LANDA MHC3-24324 MHC Pressure Washer Instruction Manual

LANDA MHC3-24324 MHC Pressure Washer

Product Information

Specifications:

• Product Name: Landa MHC
• Type: Hot Water – Gasoline Powered – Diesel/Oil Heated
• Model: MHC43500E
• Pressure Washer Models:
  • MHC3-24324 (1.110-087.0)
  • MHC3-30324 (1.110-038.0)
  • MHC4-30324 (1.110-039.0)
  • MHC4-30324E (1.110-040.0)
  • MHC4-30324E/S (1.110-041.0)
  • MHC4-35324E (1.110-042.0)
  • MHC4-35324E CAL (1.110-084.0)
  • MHC4-35324E/B (1.110-077.0)
  • MHC4-35324E/B CAL (1.110-081.0)

How To Use This Manual:
This manual contains the following sections:

• The “HOW TO USE THIS MANUAL” section will tell you how to find important information for ordering correct repair parts.
• The “SAFETY” section contains important information regarding the hazardous practices of the machine.
• The “OPERATIONS” section is to familiarize the operator with the operation and function of the machine.
• The “MAINTENANCE” section contains preventive maintenance to keep the machine and its components in good working condition.
• The “PARTS LIST” section contains assembled parts illustrations and a corresponding parts list.

Safety Information:
Thank you for purchasing this Pressure Washer. We reserve the right to make changes at any time without incurring any obligation.

Product Usage Instructions

• Component Identification:
  The component identification section will help you identify the different parts of the pressure washer.

• Assembly Instructions:
  The assembly instructions will guide you on how to properly assemble the pressure washer before use.

• Operation Instructions:
  The operation instructions will guide you on how to operate and use the pressure washer effectively.

• Detergents And General Operating Techniques:
  This section provides information on the detergents that can be used with the pressure washer and general operating techniques to achieve optimal cleaning results.

• Thermal Pump Protection:
  This section provides information on thermal pump protection to prevent damage to the pressure washer’s pump due to overheating.

• Shutdown Instructions:
  The shutdown instructions will guide you on how to properly shut down and store the pressure washer after use.

• Maintenance:
  The maintenance section contains preventive maintenance procedures to keep the pressure washer and its components in good working condition. It includes instructions on cleaning, lubrication, and regular inspection of parts.

FAQ (Frequently Asked Questions)

• Q: Where can I find the nearest Landa Dealer?
  A: You can consult our web page at www.landa.com or refer to the contact information provided on the machine data label.

• Q: How can I order repair parts?
  A: Parts can be ordered from authorized dealers. When placing an order, provide the machine model and serial number. Refer to the machine data label located on the inside of the front cover of the manual.

• Q: Where can I find the model and serial number of my machine?
  A: The model and serial number are located on a decal attached to the pressure washer.

• Q: What should I do if I encounter a safety hazard or damage to the product?
  A: Refer to the safety section of the manual for important information regarding hazardous practices. If you encounter a safety hazard or product damage, stop using the pressure washer and consult a qualified technician for repairs.

• Q: How often should I perform maintenance on the pressure washer?
  A: Regular preventive maintenance is recommended to keep the pressure washer in good working condition. Follow the maintenance procedures listed in the manual, which include cleaning, lubrication, and regular inspection of parts.

Machine Data Label

How To Use This Manual

This manual contains the following sections:

• How to Use This Manual
• Safety
• Operations
• Maintenance
• Parts List

The HOW TO USE THIS MANUAL section will tell you how to find important information for ordering correct repair parts.

Parts may be ordered from authorized dealers. When placing an order for parts, the machine model and machine serial number are important. Refer to the MACHINE DATA box which is filled out during the installation of your machine. The MACHINE DATA box is located on the inside of the front cover of this manual.

The model and serial number of your machine is located on a decal attached to the pressure washer.

• The SAFETY section contains important information regarding hazardous or unsafe practices of the machine. Levels of hazards are identified that could result in product damage, personal injury, or severe injury resulting in death.
• The OPERATIONS section is to familiarize the operator with the operation and function of the machine.

The MAINTENANCE section contains preventive main-tenance to keep the machine and its components in good working condition. They are listed in this general order:

• Storage
• Engine Maintenance
• Maintenance And Service
• Unloader Valves
• Winterizing Procedure
• High Limit Hot Water Thermostat
• Pump
• Cleaning of Coils
• Rupture Disk
• Fuel
• Burner Nozzle
• Landa MHC Oil Burner
• Landa MHC Burner Air Adjustment
• Fuel Pressure Adjustment
• Removal of Soot and Heating Coil
• Coil Reinstallation
• Troubleshooting
• Preventative Maintenance

The PARTS LIST section contains assembled parts illustrations and corresponding parts list. The parts lists include a number of columns of information:

• REF – column refers to the reference number on the parts illustration.
• PART NO. – column lists the part number for the part.
• QTY – column lists the quantity of the part used in that area of the machine.
• DESCRIPTION – column is a brief description of the part.
• NOTES – column for information not noted by the other columns.

NOTE:

• If a service or option kit is installed on your machine, be sure to keep the KIT INSTRUCTIONS which came with the kit. It contains replacement parts numbers needed for ordering future parts.
• The manual part number is located on the lower right corner of the front cover.

Introduction & Safety Information

• Thank you for purchasing this Pressure Washer.
• We reserve the right to make changes at any time without incurring any obligation.

Owner/User Responsibility:
The owner and/or user must have an understanding of the manufacturer’s operating instructions and warnings before using this pressure washer. Warning information should be emphasized and understood. If the operator is not fluent in English, the manufacturer’s instructions and warnings shall be read to and discussed with the operator in the operator’s native language by the purchaser/owner, making sure that the operator comprehends its contents.
The owner and/or user must study and maintain for future reference the manufacturers’ instructions.
The operator must know how to stop the machine quickly and understand the operation of all controls. Never permit anyone to operate the engine without proper instructions.

SAVE THESE INSTRUCTIONS

• This manual should be considered a permanent part of the machine and should remain with it if the machine is resold.
• When ordering parts, please specify the model and serial number. Use only identical replacement parts.
• This machine is to be used only by trained operators.

Important Safety Information

1. Read the owner’s manual thoroughly. Failure to follow instructions could cause a malfunction of the machine and result in death, serious bodily injury, and/or property damage.

2. Know how to stop the machine and bleed pressure quickly. Be thoroughly familiar with the controls.

3. Stay alert — watch what you are doing.
   DANGER:
   Keep wand, hose, and water spray away from electric wiring or fatal electric shock may result.

4. All installations must comply with local codes. Contact your electrician, plumber, utility company, or the selling dealer for specific details
   WARNING: This machine exceeds 85 db appropriate ear protection must be worn.

5. Always wear properly rated eye protection such as safety goggles or face shields while spraying. (Safety glasses do not provide full protection.)

6. Keep the operating area clear of all persons.
   WARNING: Flammable liquids can create fumes that can ignite, causing property damage or severe injury.
   WARNING: Risk of fire — Do not add fuel when the product is operating or still hot.
   WARNING: Do not use gasoline crankcase drainings or oil containing gasoline, solvents or alcohol. Doing so will result in fire and/or explosion.
   WARNING: Risk of fire — Do not Spray flammable liquids.

7. Allow the engine to cool for 2 minutes before refueling. If any fuel is spilled, make sure the area is dry before testing the spark plug or starting the engine. (Fire and/or explosion may occur if this is not done.)
   Gasoline engines on mobile or portable equipment shall be refueled:

   • outdoors;
   • with the engine on the equipment stopped;
   • with no source of ignition within 10 feet of the dispensing point; and
   • with an allowance made for expansion of the fuel should the equipment be exposed to a higher ambient temperature.
     In an overfilling situation, additional precautions are necessary to ensure that the situation is handled safely.
     WARNING: Risk of injury. Disconnect the battery ground terminal before servicing.

8. When in use, do not place the machine near flammable objects as the engine is hot.

9. Oil-burning appliances shall be installed only in locations where combustible dust and flammable gases or vapors are not present. Do not store or use gasoline near this machine.
   Use heating oil or diesel. If diesel is used, it is recommended to add a soot remover to every tankful to reduce soot buildup on the heating coil.

10. Use No. 1 or No. 2 heating oil (ASTM D306) only. NEVER use gasoline in your fuel oil tank. Gasoline is more combustible than fuel oil and could result in a serious explosion. NEVER use crankcase or waste oil in your burner. Fuel unit malfunction could result from contamination.

11. Do not confuse gasoline and fuel oil tanks. Keep proper fuel in the proper tank.
    WARNING: Risk of injury. Hot surfaces can cause burns. Use only designated gripping areas of the spray gun and wand. Do not place hands or feet on non-insulated areas of the pressure washer.

12. Transport/Repair with fuel tank EMPTY or with fuel shut-off valve OFF.
    WARNING: Hot discharge fluid. Do not touch or direct discharge stream at persons or animals or severe injury or death will result.

13. To reduce the risk of injury, close supervision is necessary when a machine is used near children. Do not allow children to operate the pressure washer. This machine must be attended to during operation.
    WARNING: Grip the cleaning wand securely with both hands before starting. Failure to do this could result in injury from a whipping wand.

14. Never make adjustments to the machine while in operation.

15. Be certain all quick coupler fittings are secured before using a pressure washer.
    WARNING: High pressure developed by these machines will cause personal injury or equipment damage. Keep clear of the nozzle. Use caution when operating. Do not direct discharge stream at people or animals, or severe injury or death will result.
    WARNING: Protect the machine from freezing.

16. To keep the machine in the best operating conditions, you must protect the machine from freezing. Failure to protect the machine from freezing could cause malfunction of the machine and result in death, serious bodily injury, and/or property damage. Follow the storage instructions specified in this manual.

17. Inlet water must be clean fresh water and no hotter than 90°F.
    DANGER: Risk of asphyxiation. Use this product only in a well-ventilated area.

18. Avoid installing machines in small areas or near exhaust fans. Adequate oxygen is needed for combustion or dangerous carbon monoxide will result.

19. The manufacturer will not be liable for any changes made to our standard machines or any components not purchased from us.

20. The best insurance against an accident is precaution and knowledge of the machine.
    WARNING: Be extremely careful when using a ladder, scaffolding, or any other relatively unstable location. The cleaning area should have adequate slopes and drainage to reduce the possibility of a fall due to slippery surfaces.

21. Do not allow acids, caustic, or abrasive fluids to pass through the pump.

22. 22. Never run the pump dry or leave the spray gun closed longer than 1-2 minutes.

23. Machines with shut-off spray guns should not be operated with the spray gun in the off position for extensive periods as this may cause damage to the pump.

24. Protect discharge hose from vehicle traffic and sharp objects. Inspect the condition of the high-pressure hose before use or bodily injury may result.

25. Before disconnecting the discharge hose from the water outlet, turn the burner off and open the spray gun to allow water to cool below 100ºF before stopping the machine. Then open the spray gun to relieve pressure. Failure to properly cool down or maintain the heating coil may result in a steam explosion.

26. Do not overreach or stand on unstable support. Keep good footing and balance at all times.

27. Do not operate this machine when fatigued or under the influence of alcohol, prescription medications, or drugs.

28. Use only kerosene, No. 1 home heating fuel, or diesel in the burner fuel tank. If diesel is used, add a soot remover to every tankful.
    WARNING: Do not spray the machine or any people, animals, or electrical parts.

Follow the maintenance instructions specified in the manual.

Component Identification

• Pump — Delivers a specific gpm to the high-pressure nozzle which develops pressure.
• Spray Gun — Controls the application of water and detergent onto a cleaning surface with a trigger device. Includes safety latch.
• Detergent Injector — Allows you to siphon and mix detergents.
• Wand — Must be connected to the spray gun.
• High-Pressure Hose — Connect one end to the water pump’s high-pressure discharge nipple and the other end to the spray gun.
• Rupture Disk — Secondary pressure release in the unlikely event the unloader valve fails.
• Unloader Valve — Safety device which, when the spray gun closes, prevents over-pressurization (not shown).
• NOTE: If the trigger on the spray gun is released for more than 2 minutes, water will leak from the pump protector. Warm water will discharge from the pump protector onto the floor. This system prevents internal pump damage

MHC3-24324

Assembly Instructions

• STEP 1: Attach a 3/4″ garden hose to the inlet connector. The minimum flow should be 5 gpm.

• STEP 2: Attach the high-pressure hose to discharge the nipple using a quick coupler. Lock the coupler securely into place by pulling back the coupler collar and inserting it onto the discharge nipple, then pushing the collar forward to lock in place.
  NOTE: If using a detergent injector, attach the detergent injector to the discharge nipple using a quick coupler. Attach the high-pressure hose to the other end of the detergent injector.

• STEP 3: Attach wand to spray gun using Teflon tape on threads to prevent leakage. Attach swivel connector on discharge hose to spray gun using Teflon tape on threads. Attach the swivel connector on the high-pressure hose to the spray gun using Teflon tape on the threads. Engage the safety latch to prevent from triggering the gun.

• STEP 4: Check the oil level on the sight glass on the side of the pump. Oil should be visible one-half-way up the sight glass (SAE 10W-40 non-foaming). The oil level can also be checked by using the dipstick on the top of the pump.

• STEP 5: Fill the gasoline tank and check the engine oil. Fill the fuel tank. Do not confuse gasoline and fuel oil (diesel) tanks. Keep proper fuel in proper tanks.

• STEP 6: On electric start models only, you will need to install a battery making sure that the red cable is attached to the positive terminal. Use a Group U1 garden tractor-style type of battery rated for 300 CCA (battery not included).

  • CAUTION: These machines are intended to be protected from outside environments.

Operation Instructions

• STEP 1: Turn on the water at the faucet and pull the trigger on the spray gun allowing water to flow until all air has discharged from the system. Check for water leaks; tighten as needed.

• STEP 2: Before installing the nozzle, turn on the water supply and run the machine allowing water to flush through the system until clear. Pull the wand coupler collar back and insert the desired pressure nozzle into the coupler then secure by pushing the coupler collar forward.
  NOTE: Variable pressure control wand handle must be turned clockwise to enable water to flow out of the high-pressure nozzle.
  NOTE: Do not use the electric starter for more than five seconds at a time. If the engine fails to start, release the switch and wait ten seconds before operating the starter again. When the engine starts, allow the engine switch to return to the ON position. If the engine is to be started without the battery, turn the switch to the start position and pull the rope to start. Turn off the choke.

• STEP 4: With the spray nozzle pointed away from you or anyone else, press the trigger on the spray gun to obtain pressurized cold water spray.

• STEP 3: Read the engine manual, turn on the gas valve and choke. Turn the engine switch to the START position and hold it there until the engine starts.

• STEP 5: For hot water, turn the burner switch ON when a steady stream of water flows out of the spray gun. The burner will light automatically.
  NOTE: Do not start the machine with the burner switch on.

  • The selection of high or low pressure is accompanied by turning the handle.
  • NOTE: A high-pressure nozzle must be inserted at the end of the wand to obtain high pressure. To apply soap read Detergents and General Operating Techniques section.

Detergents And General Operating Techniques

WARNING:
Some detergents may be harmful if inhaled or ingested, causing severe nausea, fainting, or poisoning. The harmful elements may cause property damage or severe injury.

• STEP 1: Use a detergent designed specifically for pressure washers. Household detergents could damage the pump. Prepare detergent solution as required by the manufacturer. Fill a container with pressure washer detergent. Place the filter end of the detergent suction tube into the detergent container.
• STEP 2: Apply a safety latch to the spray gun trigger. Secure the black detergent nozzle into a quick coupler. NOTE: Detergent cannot be applied using the Yellow nozzle.
• STEP 3: With the motor running, pull the trigger to operate the machine. Liquid detergent is drawn into the machine and mixed with water. Apply detergent to the work area. Do not allow detergent to dry on the surface.

IMPORTANT:
You must flush the detergent injection system after each use by placing the suction tube into a bucket of clean water, then run the pressure washer at low pressure for 1-2 minutes.

Thermal Pump Protection
If you run your pressure washer for 3-5 minutes without pressing the trigger on the spray gun, circulating water in the pump can reach high temperatures. When the water reaches this temperature, the pump protector engages and cools the pump by discharging the warm water onto the ground. This thermal device prevents internal damage to the pump.

Cleaning Tips
Pre-rinse the cleaning surface with fresh water. Place the detergent suction tube directly into the cleaning solution and apply to the surface at low pressure (for best results, limit your work area to sections approximately 6 feet square and always apply detergent from bottom to top). Allow detergent to remain on the surface for 1-3 minutes. Do not allow detergent to dry on the surface. If the surface appears to be drying, simply wet down the surface with fresh water. If needed, use a brush to remove stubborn dirt. Rinse at high pressure from top to bottom in an even sweeping motion keeping the spray nozzle approximately 1 foot from the cleaning surface. Use overlapping strokes as you clean and rinse any surface. For best surface cleaning action spray at a slight angle.

Recommendations:

• Before cleaning any surface, an inconspicuous area should be cleaned to test the spray pattern and distance for maximum cleaning results.
• If painted surfaces are peeling or chipping, use extreme caution as a pressure washer may remove the loose paint from the surface.
• Keep the spray nozzle a safe distance from the surface you plan to clean. High-pressure wash a small area, then check the surface for damage. If no damage is found, continue to pressure washing.

CAUTION – Never use:

• Bleach, chlorine products, and other corrosive chemicals
• Liquids containing solvents (i.e., paint thinner, gasoline, oils)
• Trisodium phosphate products
• Ammonia products or acid-based products

These chemicals will harm the machine and will damage the surface being cleaned.

Rinsing
It will take a few seconds for the detergent to clear. Apply safety latch to spray gun. Remove the black soap nozzle from the quick coupler. Select and install the desired high-pressure nozzle. NOTE: You can also stop detergent from flowing by simply removing the detergent siphon tube from

Shutdown Instructions

• STEP 1: Remove the detergent suction tube from the container and insert it into one (1) gallon of fresh water. Pull the trigger on the spray gun and siphon the water for one minute.
• STEP 2: Turn the burner switch off and continue spraying, allowing the water to cool below 100° F.
• STEP 3: Turn the engine off.
• STEP 4: Turn off water supply.
• STEP 5: Open the spray gun to relieve the remaining pressure.

Maintenance

Storage

CAUTION:
Always store your pressure washer in a location where the temperature will not fall below 32°F (0°C). The pump in this machine is susceptible to permanent damage if frozen. FREEZE DAMAGE IS NOT COVERED BY WARRANTY.

1. Stop the pressure washer, and squeeze the spray gun trigger to release pressure.
2. Detach water supply hose and high-pressure hose.
3. Turn on the machine for a few seconds, until the remaining water exits. Turn the engine off immediately.
4. Drain the gas and oil from the engine.
5. Do not allow the high-pressure hose to become kinked.
6. Store the machine and accessories in a room that does not reach freezing temperatures.

CAUTION:
Failure to follow the above directions will result in damage to your pressure washer.

1. Replenish engine oil to the upper level.
2. Drain gasoline from the fuel tank, fuel line, fuel valve, and carburetor.
3. Pour about one teaspoon of engine oil through the spark plug hole, pull the starter grip several times, and replace the plug. Then pull the starter grip slowly until you feel increased pressure which indicates the piston is on its compression stroke and leave it in that position. This closes both the intake and exhaust valves to prevent rusting of the cylinder.
4. Cover the pressure washer and store in a clean, dry place that is well-ventilated away from open flame or sparks. NOTE: The use of a fuel additive, such as STA-BIL®, or an equivalent, will minimize the formulation of fuel deposits during shortage. Such additives may be added to the gasoline in the fuel tank of the engine, or to the gasoline in a storage container.

After Extended Storage

CAUTION:
Prior to restarting, thaw out any possible ice from pressure washer hoses, spray guns or wands.

Engine Maintenance
During the winter months, rare atmospheric conditions may develop which will cause an icing condition in the carburetor. If this develops, the engine may run rough, lose power, and may stall. This temporary condition can be overcome by deflecting some of the hot air from the engine over the carburetor area.

NOTE:
Refer to the engine manufacturer’s manual for service and maintenance of the engine.

Preventative Maintenance

1. Check to see that the water pump is properly lubricated.
2. Follow Winterizing Procedures to prevent freeze damage to the pump and coils.
3. Always neutralize and flush detergent from the system after use.
4. If water is known to be high in mineral content, use a water softener in your water system or de-scale as needed.
5. Do not allow acidic, caustic, or abrasive fluids to be pumped through the system.
6. Always use high-grade quality Landa cleaning products.
7. Never run the pump dry for extended periods.
8. Use clean fuel-kerosene, No. 1 fuel oil, or diesel. Replace the fuel filter every 100 hours of operation. Avoid water-contaminated fuel as it will seize up the fuel pump. Desoot coils monthly or use an additive if diesel is being used.
9. If the machine is operated with smoking or eye-burning exhaust, coils will soot up, not letting water reach the maximum operating temperature. (See section on Air Adjustments.)
10. Never allow water to be sprayed on or near the engine or burner assembly or any electrical component.
11. Periodically delete coils as per instructions.
12. Check to see that the engine is properly lubricated.

It is advisable, periodically, to visually inspect the burner. Check air inlet to make sure it is not clogged or blocked. Wipe off any oil spills and keep this equipment clean and dry. The areas around the pressure washer should be kept clean and free of combustible materials, gasoline and other flammable vapors and liquids. The flow of combustion and ventilating air to the burner must not be blocked or obstructed in any manner.

Maintenance And Service

Unloader Valves

WARNING:
The unloader valve on this pressure washer has been factory set and sealed and is a field nonadjustable part. Tampering with the factory setting may cause personal injury and/or property damage, and will void the manufacturer warranty.

Winterizing Procedure
Damage due to freezing is not covered by warranty. Adhere to the following cold weather procedures whenever the washer must be stored or operated outdoors under freezing conditions.

During winter months, when temperatures drop below 32°F, protecting your machine against freezing is necessary. Store the machine in a heated room. If this is not possible then mix a 50/50 solution of anti-freeze/water into a 5-gallon bucket. Place a short section of garden hose into the bucket and connect it to the machine. Elevate the bucket and turn the pump on to siphon the anti-freeze through the machine. If compressed air is available, an air fitting can be screwed into the inlet connector and, by injecting compressed air, all water will be blown out of the system.

High Limit Hot Water Thermostat
For safety, each machine is equipped with a high-limit control switch. In the event that the temperature of the water should exceed its operating temperature, the high limit control will turn the burner off until the water cools.

Pumps
Use only SAE 10W-40 non-detergent oil. Change oil after the first 50 hours of use. Thereafter, change the oil every three months or at 500-hour intervals. The oil level should be checked by using the dipstick found on top of the pump or the red dot visible through the oil gauge window. Oil should be maintained at that level.

Cleaning of Coils
In alkaline water areas, lime deposits can accumulate rapidly inside the coil pipes. This growth is increased by the extreme heat build-up in the coil. The best prevention for liming conditions is to use high-quality cleaning detergents. In areas where alkaline water is an extreme problem, periodic use of Landa Coil Descaler (part #8.914-296.0) will remove lime and other deposits before the coil becomes plugged.

Periodic descaling of the heating coil is recommended so please consult your local Landa Dealer for instructions.

Rupture Disk
If pressure from the pump or thermal expansion should exceed safe limits, the rupture disk will burst allowing high pressure to be discharged through a hose to the ground. When the disk ruptures it will need to be replaced. Torque the replacement rupture disk to 35-foot pounds.

Fuel
Use clean fuel oil that is not contaminated with water and debris. Replace the fuel filter and drain tank every 100 hours of operation.

Use No. 1 or No. 2 Heating Oil (ASTM D306) only. NEVER use gasoline in your burner tank. Gasoline is more combustible than fuel oil and a serious explosion could result. NEVER use crankcase or waste oil in your burner. Fuel unit malfunction could result from contamination.

Fuel Control System

These machines utilize a fuel solenoid valve located on the fuel pump to control the flow of fuel to the combustion chamber. This solenoid valve, which is normally closed, is activated by a flow switch when water is flowing through it. When an operator releases the trigger on the spray gun, the flow of water through the flow switch stops, turning off the current to the fuel solenoid. The solenoid then closes, shutting off the supply of fuel to the combustion chamber. Controlling the flow of fuel in this way allows for an instantaneous burn or no burn situation, thereby eliminating high and low water temperatures, and combustion smoke normally associated with machines incorporating a spray gun.

CAUTION:
Periodic inspection is recommended to ensure that the fuel solenoid valve functions properly. This can be done by operating the machine and checking to see that when the trigger on the spray gun is in the off position, the burner is not firing.

Burner Nozzle
The oil burner on this machine is preset for operation at altitudes below 500 feet. If operated at higher altitudes, it may be necessary to adjust the air band for a #1 or #2 smoke spot on the Bacharach scale. To adjust, start the machine and turn the burner ON. Loosen two locking screws found on the air band and close the air band until black smoke appears from the burner exhaust vent. Note the air band position. Next, slowly open the air band until white smoke just starts to appear. Turn the air band halfway back to the previously noted position. Tighten locking screws. For higher altitudes, the air band opening may need to be increased; for lower altitudes, the air band may need to be decreased.

• For higher humidity, the air band opening may need to be increased; for lower relative humidity, the air band may need to be decreased.
• For higher ambient temperatures the air band opening may need to be increased; for lower ambient temperatures, the air band opening may need to be decreased.
• Adjust to your operating location’s environment as needed for the best smoke spot and performance compliant with local, state, and federal regulations.

Landa MHC Oil Burner

Burner Air Adjustment:
To adjust fuel pressure, First, install a pressure gauge into the port just after the pump fuel exit. Turn the adjusting screw (located at the regulator port) clockwise to increase, and counterclockwise to decrease. Do not exceed 200 psi or lower the pressure below 130 PSI, when checked at the post-pump pressure port.

The fuel pressure may need to be adjusted due to altitude. For every 500 ft altitude above sea level, the boiling point of water goes down 1 °F. At high altitude environments, this boiling point change may require the heat input to be lowered so the water input does not turn to steam earlier than at the factory settings and activate the pressure sensors and pressure relief equipment when the unit is operated and much higher altitudes from factory settings or local dealer site settings. Check with your dealer before making local site fuel pressure adjustments.

Also, as ambient temperature changes seasonally, the fuel temperature in the feed tank and air temperature inlet can impact fuel flow. In more extreme temperatures, this local-site adjustment may also require different fuel nozzles for fuel inlet temperatures that are at seasonal extremes (higher or lower) in locations where the temperature changes are beyond moderate temperatures of between 40°F and 90°F. Colder temperatures will make for a thicker flow and less fine fuel spray while hotter temperatures will make for a thinner flow and a more fine spray with the same nozzle. Consider alternate nozzle configurations from the baseline factory-supplied nozzle for operating in such temperature extremes if performance is not meeting needs with air band and fuel pressure settings alone.

NOTE:
When changing the fuel pump, a by-pass plug must be installed in the return line port, or the fuel pump will not prime.

Landa MHC Burner Air Adjustment

CAUTION:
If white smoke appears from the burner exhaust vent during start-up or operation, discontinue use and readjust air bands.

NOTE:
If a flue is installed, have a professional serviceman adjust your burner for a #1 or #2 smoke spot on the Bacharach scale.

Removal of Soot and Heating Coil
In the heating process, fuel residue in the form of soot deposits may develop on the heating coil and block airflow which will affect burner combustion. When soot has been detected on visual observation, the soot on the coil must be washed off after following the coil removal steps.

1. Disconnect the hose from the pump/unloader to the inlet side of the coil.

2. Remove the thermostat sensor.

3. Remove the tank head assembly by unscrewing six screws and lifting the top wrap off.

4. Fold back insulation blanket.

5. Remove the two pipe nipples and associated fittings.

6. Remove bolt Item 75, which holds down the coil to the bottom wrap.

7. Lift the coil out of the bottom wrap.
   CAUTION: The coil weighs about 80 lbs. Use proper lifting techniques.

8. Replace or repair any insulation found to be torn or broken.

9. Clean, repair, and replace the coil by reversing the above steps.

Coil Re-installation
Reinstall by reversing the above steps 9 through 1.

Final Note
The 12 VDC burner systems can draw as much as 18 amps! For such motors to run properly, the battery and engine charging system must be kept in good condition, and the engine must run fast enough to adequately charge the battery. Do not throttle down the engine for any length of time.

Troubleshooting

LOW OPERATING PRESSURE

| Water supply is insufficient| Use larger supply hose; clean filter at water inlet.
Spray nozzle is old, worn or incorrect| Match the nozzle number to the machine and/or

replace with new nozzle.

Belt slips| Tighten or replace belt; use correct belt.
Plumbing or hose is leaking| Check plumbing system for leaks. Re-tape leaks with

teflon tape.

Unloader is faulty or mis-adjusted| Adjust unloader for proper pressure. Install repair kit

when necessary or replace.

Packing in pump is worn| Install new packing kit.
Discharge valve in pump or inlet is fouled

or dirty

| Check inlet and discharge valve.
Discharge valve or inlet is worn| Replace with valve kit.
Spray nozzle has obstruction| Remove obstruction.
Steam pressure control valve is leaking

(where applicable)

| Rebuild or replace as necessary.

Engine RPM is slow

| Set engine speed at proper specifications. See serial

plate. The gasoline engine is preset for operation at altitudes below 1000 feet above sea level. If operated at higher altitudes, it may be necessary to install a high altitude main jet in the carburetor. Contact you local authorized engine sales and service center for details.

BURNER WILL NOT LIGHT

| There is little or no fuel| Fill tank with fuel.
Improper fuel or water in fuel| Drain fuel tank and fill with proper fuel.
Fuel line is clogged| Clean or replace fuel line.
Fuel filter is plugged| Replace fuel filter as needed.
Burner air bands are mis-adjusted| Readjust air bands for clean burn.
Little or no fuel pressure from fuel pump| Increase fuel pressure to specification and/or replace

fuel pump.

Burner transformer is faulty| Test transformer for proper arc between contacts.

Replace as needed.

Electrical wiring is disconnected or has

short in it

| All wire contacts should be clean and tight with no

breaks in wire.

Flex coupling is slipping on fuel pump shaft or burner motor shaft| Replace if needed.

ON-OFF switch is defective

| Check for electrical current reaching burner assembly with burner switch on. Replace switch if needed.
Heavy sooting on coil and burner can cause interruption of air flow and shorting of electrodes| ****

Clean as required.

Electrode setting is improper| Check and reset according to diagram in manual.
30 amp circuit breaker tripped| Push in reset button.
Bridge rectifier defective| Test and replace.
12V DC relay defective| Test and replace.

Fuel is not reaching combustion chamber

| Check fuel pump for proper flow. Check solenoid flow

switch on machines with spray gun control for proper on-off flow control.

MACHINE SMOKES WHILE BURNER UNIT IS RUNNING

OR

UNIT SMOKES AT COLD-START ONLY WHEN BURNER IS OFF

| Fuel is improper or water is in fuel| Drain tank and replace contaminated fuel.
Air adjustment is improper| Readjust air bands on burner assembly.
Fuel pressure is low 140 psi for burner| Adjust fuel pump pressure to specifications.
Burner nozzle is plugged or dirty| Replace nozzle. Check parts breakdown for nozzle size.
Burner nozzle spray pattern is faulty| Replace nozzle. Check parts breakdown for nozzle size.
Coil and burner assembly have heavy accumu- lation of soot| Remove coils and burner assembly, clean thoroughly. Call local dealer.
Electrode setting is misaligned| Realign electrodes to specifications.
Smoke stack has obstruction| Check for blockage or other foreign objects.
Engine RPM is low| Increase RPM to correct specs. See serial

plate.

Fuel Pressure is too high for clean burn (fuel PSI above 140 and below 200) and smokes when burner is off| Reduce fuel pressure PSI/Increase air band set for cleaner without max water heat loss

LOW WATER

TEMPERATURE

| Fuel is improper or has water in it| Replace with clean and proper fuel.
Fuel pressure is low| Increase fuel pressure.
Fuel pump is weak| Check fuel pump pressure. Replace pump if

needed.

Fuel filter is partially clogged| Replace as needed.
Soot buildup on coils is not allowing heat transfer| Clean coils.
Burner nozzle is improper| Call your local dealer for proper nozzle.

WATER TEMPERATURE TOO HOT

| Incoming water to machine is warm or hot| Lower incoming water temperature.
Fuel pump pressure is too high| Call your local dealer for proper fuel pressure.
Fuel pump is defective| Replace fuel pump.
Fuel nozzle is incorrect size| See parts breakdown or serial plate for proper

size.

Water supplied is insufficient| Check water GPM to machine.
Water flow is restricted| Check nozzle for obstruction and proper size. Check serial plate for correct size.
PRESENCE OF WATER IN OIL| Oil seal is worn| Check and replace if necessary.
Air humidity is high| Check and change oil twice as often.
Packing is worn or bad| Check and replace if necessary.

DETERGENT NOT DRAWING

| Air is leaking| Tighten all clamps. Check detergent lines for holes.
Filter screen on detergent suction hose is plugged| Clean or replace.
Detergent has high viscosity| Dilute detergent to specifications.
DETERGENT NOT DRAWING CONT.| Injector head may be blocked, dirty or damaged.| Clean and make sure ball and spring behind detergent hose barb or injector body are working properly.
---|---|---
Not using soap nozzle| Insert soap nozzle into wand coupler.
Detergent level is low| Add detergent if needed.

PUMP RUNNING

NORMALLY BUT PRESSURE LOW ON INSTALLATION

| Pump is sucking air| Check water supply and possibility of air seepage.
Valves are sticking| Check and clean or replace if necessary.
Unloader valve seat is faulty| Check and replace if necessary.
Nozzle sized incorrectly| Check and replace if necessary (see serial plate for proper size).
Packing piston is worn| Check and replace if necessary.

FLUCTUATING PRESSURE

| Valves are worn| Check and replace if necessary.
Valve has a blockage| Check and replace if necessary.
Pump is sucking air| Check water supply and air seepage at joint in suction line.
Packing piston is worn| Check and replace if necessary.

Gasoline Engine Altitude

| The gasoline engine is preset for operation at altitudes

below 1000 feet above sea level. If operated at higher alti- tudes, it may be necessary to install a high altitude main jet in the carburetor. Contact your local authorized engines sales and service center for details.

PUMP NOISY

| Air is in suction line| Check water supply and connections on suction line.
Inlet or discharge valve springs are weak or broken| Check and replace if necessary.
Excessive matter is in valves| Check and replace if necessary.
Bearings are worn| Check and replace if necessary.

WATER DRIPPING FROM UNDER PUMP

| Piston packing is worn| Check and replace if necessary.
O-Ring plunger retainer is worn| Check and replace if necessary.
Piston is cracked| Check and replace if necessary.
Pump protector is worn| Lower water supply pressure. Do not run the spray gun closed longer than 5 minutes.
OIL DRIPPING| Oil seal is worn| Check and replace if necessary.
EXCESSIVE VIBRATION

IN DELIVERY LINE

| ****

Valves are functioning irregularly

| ****

Check and replace if necessary.

BURNER MOTOR WILL NOT RUN

| Fuel pump has seized| Replace fuel pump.
Burner fan loose or misaligned| Position correctly and tighten set screw.
Control switch is defective| Replace switch.
There is a loose wire| Check and replace or tighten wiring.
Burner motor is defective| Replace motor.
RELIEF VALVE LEAKS WATER| Relief valve is defective| Replace or repair relief valve.

Preventative Maintenance
This pressure washer was produced with the best available materials and quality craftsmanship. However, you as the owner have certain responsibilities for the correct care of the equipment. Attention to regular preventative maintenance procedures will assist in preserving the performance of your equipment. Contact your dealer for maintenance. Regular preventative maintenance will add many hours to the life of your pressure washer. Perform maintenance more often under severe conditions.

MAINTENANCE SCHEDULE

Oil Change Record
Check pump oil level before first use of your new Power Washer. Change pump oil after the first 50 hours and every month or 500 hours thereafter. Use SAE 10W-40 non-foaming oil.

9.800-950.0 • Printed in U.S.A.

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