WEIL McLAIN GV90 Plus Series 2 Gas Fired Water Boilers User Manual

WEIL McLAIN GV90 Plus Series 2 Gas-Fired Water Boilers

Product Specifications

• Product Name : GV90+ Series 2 Gas-Fired Water Boiler
• Part Number : 550-143-009/0324
• Series: 2

Product Usage Instructions

Precautions:

Ensure to read all warnings and definitions provided in the manual to prevent accidents and ensure safe operation of the boiler.

Prevent Air Contamination:

Make sure the boiler air is piped according to the manual to avoid contaminants. Refer to the list of air contaminants to avoid.

Maintain Boiler:

Set up a maintenance plan using the schedule included in the manual. Schedule an annual start-up by a qualified service technician before every heating season.

Locate Boiler Components:

Refer to the manual for illustrations and descriptions of various boiler components.

Start or Shutdown Boiler:

Follow the Operating instruction sheet details provided in the manual to correctly start or shut down the boiler.

Troubleshoot Common Problems:

Refer to the common problems/solutions table in the manual to resolve typical heating system or boiler issues.

FAQ

• Q: How often should I have my boiler serviced?
  • A: It is recommended to have the boiler serviced and inspected by a qualified service technician at least annually to ensure safe and efficient operation.
• Q: What should I do if I smell gas?
  • A: If you smell gas, do not operate any electrical appliances, extinguish any open flames, do not touch any electrical switches, and evacuate the area immediately. Contact your gas supplier or emergency services from a safe location.

WARNING If the information in this manual is not followed exactly, a fire or explosion may result, causing property damage, personal injury or loss of life.

Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance

— WHAT TO DO IF YOU SMELL GAS —

• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any telephone in your building.
• Immediately call your gas supplier from a neighbor’s telephone. Follow the gas supplier’s instructions.
• It you cannot reach your gas supplier, call the fire department. Installation & service must be performed by a qualified installer, service technician or the gas supplier.

GV90+ Series 2 GAS-FIRED WATER BOILER — User’s Information Manual

Hazard definitions

The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or to important information concerning the life of the product.

DANGER
Indicates the presence of hazards that will cause severe personal injury, death or substantial property damage.

WARNING
Indicates the presence of hazards that can cause severe personal injury, death or substantial property damage.

CAUTION

Indicates the presence of hazards that will or can cause minor personal injury or property damage.

NOTICE

Indicates special instructions on installation, operation or maintenance that are important but not related to personal injury or property damage.

Boiler service and maintenance

WARNING The Boiler manual is for use only by a qualified heating installer/ service technician. Refer only to this User’s Information Manual for your reference. Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury (exposure to hazardous materials) or loss of life. Installation and service must be performed by a qualified installer, service agency or the gas supplier (who must read and follow the supplied instructions before installing, servicing, or removing this boiler. This boiler contains materials that have been identified as carcinogenic, or possibly carcinogenic, to humans).

NOTICE

When calling or writing about the boiler— Please have the boiler model number from the boiler rating label and the Consumer Protection (CP) number from the label located on the top of the boiler next to the air inlet connection.

STOP!! — Read before proceeding

WARNING

User – Have this boiler serviced/inspected by a qualified service technician, at least annually.

WARNING

Failure to adhere to the guidelines on this page can result in severe personal injury, death or substantial property damage.
Boiler service and maintenance –

• To avoid electric shock, disconnect all electrical supplies to the boiler before performing maintenance if the wiring will\ be exposed.
• To avoid severe burns, allow the boiler to cool before performing maintenance.
• You must maintain the boiler as outlined in this manual and have the boiler started up and serviced at least an- annually by a qualified service technician to ensure boiler/ system reliability.

Carbon monoxide detector –

• This product burns gas to produce heat. The appliance must be properly installed, operated, and maintained to avoid exposure to appreciable levels of carbon monoxide, and the installer is required to confirm that at least one carbon monoxide alarm is installed in the living space before the appliance is put into operation. It is important for the carbon monoxide alarms to be installed, maintained, and replaced following the alarm manufacturer’s instructions and applicable local codes.

• For Direct Exhaust units, a carbon monoxide detector is required in the same room and near the boiler. The carbon monoxide detector must be wired on the same electrical circuit as the boiler.
  Boiler operation –

• Do not block the flow of combustion or ventilation air to the boiler. This boiler is equipped with a control that will automatically shut down the boiler should air or vent be blocked. If vent or air blockage is easily accessible and removable, remove it. The boiler should attempt to restart within an hour. (If a blockage is not obvious or cannot be removed, have the boiler and system checked by a qualified service technician.)

• Do not allow contaminated air to enter the boiler room (or air inlet pipe if directly vented). See page 4 for details.

• Do not use this boiler if any part has been underwater. Immediately call a qualified service technician to inspect the boiler and to replace any part of the control system and any gas control that has been under water.

• Should overheating occur or the gas supply fail to shut oft, DO NOT turn off or disconnect the electrical supply to the circulator. Instead, shut off the gas supply at a location external to the appliance.
  Combustion air –

• DO NOT install combustion air intake where there is a risk of combustion air contamination.

Boiler water —

• Have boiler water chemistry checked at least annually by a qualified service technician. poet use patrollers adelainessalimmay bedands aged. This can result in substantial property damage.
• DO NOT use “homemade cures” or “boiler patent medicines”. Serious damage to the boiler, personnel, and/or property may result.
• Leaks in boiler. in miles beep anadosento system. Continual fresh make-up water will reduce boiler life. Mineral water in hea tachs here des be prayer carried is the make-up water can cause internal corrosion.
• Do not add cold water to a hot boiler. Thermal shock can cause the boiler heat exchanger to crack.

Freeze protection fluids –

• NEVER use automotive or standard glycol antifreeze. Use only freeze-protection fluids made for hydronic systems.
  Throwly eling in any retire boilers turer. that has used glycol before installing the new boiler.

CAUTION Frozen Water Damage Hazard

• Residences or buildings that are unattended in severely cold weather, boiler system components failures, power outages, or other electrical system failures could result in frozen plumbing and water damage in a matter of hours. For your protection, take preventative actions such as having a security system installed that operates during power outages, senses low temperatures, and initiates an effective action. Consult with your boiler contractor or a home security agency.

DANGER

If any part of a boiler, burner or its con- trolls has been sprayed with or submerged under water, either partially or fully, DO NOT attempt to operate the boiler until the boiler has been either replaced or completely repaired, and inspected, and you are sure that the boiler and all components are in good condition and fully reliable. Otherwise, by operating this boiler, you will cause a fire or explosion hazard, and an electrical shock hazard, leading to serious injury, death, or substantial property damage. See the instructions at right.

Saltwater Damage – The exposure of boiler components to saltwater can have both immediate and long-term effects. While the immediate effects of saltwater damage are similar to those of freshwater (shorting out of electrical components, washing out of critical lubricants, etc.), the salt and other contaminants left behind can lead to longer-term issues after the water is gone due to the conductive and corrosive nature of the salt residue. Therefore, Weil-McLain equipment contaminated with saltwater or polluted water will no longer be covered under warranty and should be replaced.

Electrical Damage – If any electrical component or wiring came into contact with water, or was suspected to have come into contact with water, replace the boiler with a new Weil-McLain boiler.

Prevent combustion air contamination —

Air contamination

Common household and hobby products often contain fluorine or chlorine compounds. When these chemicals pass through the boiler, they can form strong acids in the vent system or boiler. The acid can eat through the vent or boiler wall, causing serious damage and presenting a possible threat of flue gas spillage into the building.

Please read the information below. If the contaminating chemicals will be present, have your installer pipe the boiler air from outside per the Boiler manual.

WARNING

If the boiler is installed in any area likely to cause contamination, or if products that would contaminate the air cannot be removed, you must pipe combustion air to the boiler air intake.

Contaminated combustion air will damage the boiler and vent system, resulting in possible severe personal injury, death or substantial property damage. Do not operate a GV90+ boiler in a laundry room or pool facility, for example, without using ducted outside air. These areas will always contain contaminants.

Combustion air contamination:

WARNING

Ensure that the combustion air will not contain any of the contaminants in Figure 1.
Combustion air supply openings or intake terminations must NOT be near a swimming pool, for example.
Avoid areas subject to exhaust fumes from laundry facilities- ties. These areas will always contain contaminants.

Hazard definitions

The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or to important information concerning the life of the product.

DANGER

Indicates the presence of hazards that will cause severe personal injury, death or substantial property damage.

WARNING

Indicates the presence of hazards that can cause severe personal injury, death or substantial property damage.
CAUTION

Indicates the presence of hazards that will or can cause minor personal injury or property damage.

NOTICE

Indicates special instructions on installation, operation or maintenance that are important but not related to personal injury or property damage.

Boiler service and maintenance

WARNING

The Boiler manual is for use only by a qualified heating installer/ service technician. Refer only to this User’s Information Manual for your reference. Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury (exposure to hazardous materials) or loss of life. Installation and service must be performed by a qualified installer, service agency or the gas supplier (who must read and follow the supplied instructions before installing,  servicing, or removing this boiler. This boiler contains materials that have been identified as carcinogenic, or possibly carcinogenic, to humans).

NOTICE

When calling or writing about the boiler— Please have the boiler model number from the boiler rating label and the Consumer Protection (CP) number from the label located on the top of the boiler next to the air inlet connection.

STOP!! — Read before proceeding

WARNING

User — Have this boiler serviced/inspected by a qualified service technician, at least annually.

WARNING

Failure to adhere to the guidelines on this page can result in severe personal injury, death or substantial property damage.

Boiler service and maintenance —

• To avoid electric shock, disconnect all electrical supplies to the boiler before performing maintenance if the wiring will be exposed.
• To avoid severe burns, allow the boiler to cool before performing maintenance.
• You must maintain the boiler as outlined in this manual and have the boiler started up and serviced at least annually by a qualified service technician to ensure boiler/system reliability.

Carbon monoxide detector —

• This product burns gas to produce heat. The appliance must be properly installed, operated, and maintained to avoid exposure to appreciable levels of carbon monoxide and the installer is required to confirm that at least one carbon monoxide alarm is installed in the living space before the appliance is put into operation. It is important for the carbon monoxide alarms to be installed, maintained, and replaced following the alarm manufacturer’s instructions and applicable local codes.
• For Direct Exhaust units, a carbon monoxide detector is required in the same room and near the boiler. The carbon monoxide detector must be wired on the same electrical circuit as the boiler.

Boiler operation —

• Do not block the flow of combustion or ventilation air to the boiler. This boiler is equipped with a control that will automatically shut down the boiler should air or vent be blocked. If the vent or air blockage is easily accessible and removable, remove it. The boiler should attempt to restart within an hour. (If the blockage is not obvious or cannot be removed, have the boiler and system checked by a qualified service technician.)

• Do not allow contaminated air to enter the boiler room (or air inlet pipe if direct vented).  for details.

• Do not use this boiler if any part has been underwater.
  Immediately call a qualified service technician to inspect the boiler and to replace any part of the control system and any gas control that has been under water.

• Should overheating occur or gas supply fail to shut off, DO NOT turn off or disconnect the electrical supply to the circulator. Instead, shut off the gas supply at a location external to the appliance.

Combustion air —

DO NOT install combustion air intake where there is a risk of combustion air contamination.
Boiler water —

• Have boiler water chemistry checked at least annually by a qualified service technician.
• DO NOT use petroleum-based cleaning or sealing compounds in the boiler system. Gaskets and seals in the system may be damaged. This can result in substantial property damage.
• DO NOT use “homemade cures” or “boiler patent medicines”. Serious damage to the boiler, personnel, and/or property may result.
• Leaks in the boiler or piping must be repaired at once to prevent make-up water. Use this boiler ONLY in a closed-loop system.  Continual fresh make-up water will reduce boiler life. Mineral buildup in heat
• exchangers reduces heat transfer, overheats the materials, and causes failure. The addition of oxygen carried in by make-up water can cause internal corrosion.
• Do not add cold water to hot boiler. Thermal shock can cause the boiler heat exchanger to crack.

Freeze protection fluids —

• NEVER use automotive or standard glycol antifreeze. Use only freeze-protection fluids made for hydronic systems. Follow all guidelines given by the antifreeze manufacturer.
  Thoroughly clean and flush any replacement boiler system that has used glycol before installing the new boiler.

CAUTION Frozen Water Damage Hazard

Residences or buildings that are unattended in severely cold weather, boiler system components failures, power outages, or other electrical system failures could result in frozen plumbing and water damage in a matter of hours. For your protection, take preventative actions such as having a security system installed that operates during power outages, senses low temperatures, and initiates an effective action. Consult with your boiler contractor or a home security agency

DANGER

If any part of a boiler, burner or its controls has been sprayed with or submerged under water, either partially or fully, DO NOT attempt to operate the boiler until the boiler has been either replaced or completely repaired, inspected, and you are sure that the boiler and all components are in good condition and fully reliable. Otherwise, by operating this boiler, you will cause a fire or explosion hazard, and an electrical shock hazard, leading to serious injury, death, or substantial property damage. See the instructions at right.

Saltwater Damage — The exposure of boiler components to saltwater can have both immediate and long-term effects. While the immediate effects of saltwater damage are similar to those of freshwater (shorting out of electrical components, washing out of critical lubricants, etc.), the salt and other contaminants left behind can lead to longer-term issues after the water is gone due to the conductive and corrosive nature of the salt residue. Therefore, Weil-McLain equipment contaminated with saltwater or polluted water will no longer be covered under warranty and should be replaced.

Electrical Damage — If any electrical component or wiring came into contact with water, or was suspected to have come into contact with water, replace the boiler with a new Weil-McLain boiler.

Prevent combustion air contamination —

Air contamination

Common household and hobby products often contain fluorine or chlorine compounds. When these chemicals pass through the boiler, they can form strong acids in the vent system or boiler. The acid can eat through the vent or boiler wall, causing serious damage and presenting a possible threat of flue gas spillage into the building. Please read the information below. If the contaminating chemicals will be present, have your installer pipe the boiler air from outside per the Boiler manual.

If the boiler is installed in any area likely to cause contamination, or if products that would contaminate the air cannot be removed, you must pipe combustion air to the boiler air intake.

WARNING

Contaminated combustion air will damage the boiler and vent system, resulting in possible severe personal injury, death or substantial property damage. Do not operate a GV90+ boiler in a laundry room or pool facility, for example, without using ducted outside air. These areas will always contain contaminants.

Combustion air contamination:

WARNING

Ensure that the combustion air will not contain any of the contaminants in Figure 1. Combustion air supply openings or intake terminations must NOT be near a swimming pool, for example. Avoid areas subject to exhaust fumes from laundry facilities. These areas will always contain contaminants.

Figure 1 Corrosive contaminants and sources

Products to Avoid

Spray cans containing chloro/fluorocarbons
Permanent wave solutions
Chlorinated waxes/cleaners
Chlorine-based swimming pool chemicals
Calcium chloride used for thawing
Sodium chloride used for water-softening
Refrigerant leaks
Paint or varnish removers
Hydrochloric acid/muriatic acid
Cement and glues
Antistatic fabric softeners used in clothes dryers
Chlorine-type bleaches, detergents, and cleaning solvents found in household laundry rooms
Adhesives used to fasten building products and other similar products
Excessive dust and dirt
Areas likely to have contaminants
Dry cleaning/laundry areas and establishments
Swimming pools
Metal fabrication plants
Beauty shops
Refrigeration repair shops
Photo processing plants
Auto body shops
Plastic manufacturing plants
Furniture refinishing areas and establishments
New building construction

Perform maintenance per the schedule below

Figure 2 Service and maintenance schedules

Service technician

(see Boiler Manual for instructions)

Annual start-up| Follow the procedures listed in the Boiler Manual.
Owner maintenance

(see the following pages for instructions)

Daily|

•   Check boiler area

•   Check air openings

•   Check pressure gauge

Monthly|

•   Check boiler interior piping

•   Check venting system

•   Check air vents

•   Check condensate drain system

•   Check relief valve

Periodically| •   Test low water cutoff

•   Clean vent termination/air intake screens

Every 6 months| •   Oil blower motor (if required)

•   Operate relief valve

End of season| •   Shut down procedure

User maintenance procedures

WARNING

The boiler should be inspected and started annually, at the beginning of the heating season, only by a qualified service technician. In addition, the maintenance and care of the boiler designated on page 5 and explained on the following pages must be performed to assure maximum boiler efficiency and reliability. Failure to service and maintain the boiler and system could result in equipment failure,causing possible severe personal injury, death or substantial property damage.

CAUTION

The following information provides detailed instructions for completing the maintenance items listed in the maintenance schedule, page 5. In addition to this maintenance, the boiler must be serviced and started up at the beginning of each heating season by a qualified service technician.

Check boiler area

WARNING

To prevent the potential of severe personal injury, death or substantial property damage, eliminate all materials discussed below from the boiler vicinity. If contaminants are found: Remove products immediately from the area. If they have been there for an extended period, call a qualified service technician to inspect the boiler and vent system for possible damage from acid corrosion.

If products cannot be removed, immediately call a qualified service technician to install an outside combustion air source for the boiler (if not already installed).

1. Combustible/flammable materials — Do not store combustible materials, gasoline or any other flammable vapors or liquids near the boiler. Remove immediately if found.
2. Air contaminants — Products containing chlorine or fluorine, if allowed to contaminate the boiler intake air, will cause acidic condensate in the vent and boiler. This will cause significant damage to the vent and/or boiler if allowed to continue. Read the list of potential materials listed on page 4 of this manual. If any of these products are in the room from which the boiler takes its combustion air, they must be removed immediately or the boiler combustion air must be supplied from outside.

Check air openings

1. Verify that combustion and ventilation air openings to the boiler room and/or building are open and unobstructed.
2. Verify that boiler vent discharge and air intake are clean and free of obstructions. Remove any debris on the air intake or flue exhaust openings.

Check boiler pressure/temperature gauge

1. Make sure the pressure reading on the boiler pressure/temperature gauge does not exceed 24 psig. Higher pressure may indicate a problem with the expansion tank.
2. Contact a qualified service technician if the problem persists

User maintenance procedures (continued)

Check boiler interior piping

1. Remove the boiler jacket top.
2. Visually inspect for leaks around internal piping, circulators, relief valves,s and other fittings. Immediately call a qualified service technician to repair any leaks.

WARNING: Have leaks fixed at once by a qualified service technician. Continual fresh makeup water will reduce boiler life. Minerals can build up in sections, reducing heat transfer, overheating cast iron, and causing section failure.

WARNING: Do not use petroleum-based cleaning or sealing compounds in the boiler system. Severe damage to boiler and system components can occur, resulting in possible severe personal injury, death or substantial property damage.

Check venting system

1. Visually inspect the flue gas vent piping for any signs of blockage, leakage or deterioration of the piping. Notify your qualified service technician at once if you find any problem.

WARNING

Failure to inspect the vent system as noted above and have it repaired by a qualified service technician can result in vent system failure, causing severe personal injury or death.

Check automatic air vents (if used — use automatic air vents with diaphragm-type expansion tanks only)

1. See Figure 3.
2. Remove the cap from any automatic air vent in the system and check operation by depressing valve “B” slightly with the tip of a screwdriver.
3. If the air vent valve appears to be working freely and not leaking, replace cap “A”, twisting all the way on.
4. Loosen cap “A” one turn to allow vent to operate.
5. Have vent replaced if it does not operate correctly.

Figure 3 Automatic air vent

User maintenance procedures (continued)

Check condensate system

1. NOTICE — To improve clarity, this illustration of the condensate trap is shown with no air inlet pipe attached. If your boiler has an air pipe connected here, DO NOT tamper with it. The trap is also shown as item m .
2. Inspect the condensate trap (item 1 in the illustration at right). If the trap does not contain water, turn off the boiler ON/OFF switch and call your boiler service technician immediately.
3. Item 3 in the illustration is the drain tubing to the condensate pump. Inspect this tubing or piping, making sure it is in good condition and not obstructed.

WARNING

If the condensate trap is dry or the condensate drain line is damaged or obstructed, there is a risk of flue gas flow into the building. The boiler must not be operated and must be inspected and serviced only by a qualified service technician. Failure to comply with this directive could result in the possibility of severe personal injury, death or substantial property damage.

Check boiler relief valve

1. Inspect the boiler relief valve and the relief valve discharge pipe for signs of weeping or leakage.
2. If the relief valve often weeps, the expansion tank may not be working properly. Immediately contact your qualified service technician to inspect the boiler and system.

Test Low Water Cutoff

1. Test the low water cutoff periodically during the heating season by pressing the LWCO TEST button on the control module. Allow the boiler to fire, then press the LWCO TESTbutton. The boiler should cease firing and shut down. The LWCO led should light. Let go of the TEST button and the boiler should resume operation. The LWCO led should no longer be lit.

Clean vent termination & air intake screens 

1. Remove all lint and debris from both the boiler air intake screen and the flue discharge screen.
2. The boiler control module will sense blockage of the air intake or flue and lockout if the blockage is excessive. It will signal the failure by flashing the appropriate indicator lights on the control board.
3. If removing the debris does not allow the boiler to operate correctly afterward, contact your qualified service technician to inspect the boiler and vent/air systems.

User maintenance procedures

Oil blower motor

1. Oil blower motor only if required, some GV90+ boilers may have an alternate sealed bearing blower motor, (No oiling required).
2. Remove the jacket top panel to access the blower motor.
   • WARNING
   • Use only Anderol 465 to lubricate the blower motor. Do not use common universal household oils.
3. Use only Anderol 465. DO NOT use household universal oils.
4. See Figure 4.
5. Place a few drops of oil in each of the two oiler cups on the side of the blower motor.

Operate boiler relief valve

1. Before proceeding, verify that the relief valve outlet has been piped to a safe place of discharge, avoiding any possibility of scalding from hot water
   • WARNING
   • To avoid water damage or scalding due to valve operation, a metal discharge line must be connected to relief valve outlet and run to a safe place of disposal. This discharge line must be installed by a qualified heating installer or service technician in accordance with the instructions in the GV90+ Boiler Manual. The discharge line must be terminated so as to eliminate the possibility of severe burns should the valve discharge.
2. Read the boiler pressure/temperature gauge to make sure the system is pressurized.
3. Lift the relief valve top lever slightly, allowing water to relieve through the valve and discharge piping.
4. If water flows freely, release the lever and allow the valve to seat. Watch the end of the relief valve discharge pipe to ensure that the valve does not weep after the line has had time to drain. If the valve weeps, lift the seat again to attempt to clean the valve seat. If the valve continues to weep afterward, contact your qualified service technician to inspect the valve and system.
5. If water does not flow from the valve when you lift the lever completely, the valve or discharge line may be blocked. Immediately shut down the boiler, following the lighting instructions on the inside jacket top. Call your qualified service technician to inspect the boiler and system.

Follow boiler shutdown procedure

1. Follow “TO TURN OFF GAS TO APPLIANCE” on the Operating instructions on the inside of the jacket top panel. You will also find these instructions on page 12 of this manual.
2. Do not drain system unless exposure to freezing temperatures will occur.
3. Do not drain the system if it is filled with an antifreeze solution.
4. Do not shut down boilers used for domestic water heating. They must operate year-round.

How it works . . .

1. 1 Integrated boiler control

   • The Integrated Boiler Control (IBC) responds to signals from the room thermostat, air pressure switch, inlet water sensor, boiler water temperature/LWCO sensor and boiler limit circuit to operate the circulators, gas valve, igniter and blower. When a room thermostat calls for heat, the IBC starts the system circulator and blower.
   • The IBC runs the blower to purge the boiler flue passages, then turns on the igniter and lets it warm up. After igniter warm-up, the IBC opens the gas valve, turns the igniter off, and checks for Bflame. The flame must come on within 4 seconds or the IBC will shut down and try the full cycle again. When the room thermostat is satisfied, the IBC turns off the boiler components and waits for the next heat call. The IBC indicator lights show normal sequence when the lights are on steady. When a problem occurs, the IBC flashes combinations of lights which indicate the most likely reason for the problem. While attempting to satisfy the heat demand, the control module monitors the boiler temperature changes via the temperature sensors and determines whether or not theavailable hot water will satisfy the demand, only running the circulator. If additional heat is needed, the sequence continues. When DHW (if used) calls for heat, sequence above is bypassed.

2. Transformer
   The control transformer reduces line voltage to 24 volts for the gas valve and limit circuit.

3. Blower

   • The blower pulls in air and mixes it with gas from the gas valve. The blower forces this mixture into the burner for combustion inside the boiler chamber.

4. Recuperator

   • The recuperator is a stainless steel heat exchanger that increases boiler efficiency by extracting additional heat from the flue gases. Return water passes through the recuperator before entering the boiler.

5. Water temperature/LWCO sensor

   • The water temperature/LWCO sensor provides a signal to the control module to turn off the gas valve if the temperature in the boiler goes above its setting. (The circulator will continue to run as long as there is a call for heat.) The low water cutoff (LWCO) sensor will shut off the boiler when the water level drops below sensor.

6. System circulator

   • The system circulator circulates water through the external (system) piping. The flow rate of the circulator is controlled by the IBC, depending on the temperature of the water entering the boiler sections. Pump must remain on boiler — do not remove.

7. Bypass circulator

   • The IBC operates the bypass circulator to mix hot water from the boiler outlet with colder return water from the system as needed to prevent condensation of flue gases in the cast iron heat exchanger. When the water returning to the boiler is below 140°F, the IBC regulates the bypass circulator and system circulator flow rates to raise the return water temperature up to 140°F before it enters the cast iron sections. By balancing these flow rates, the IBC can protect against condensation even if return water is as low as 60°F. Pump must remain on boiler — do not remove.

8. Air pressure switch

   • The air pressure switch signals the IBC, telling the control whether air is moving through the blower.

9. eturn water temperature sensor

   • The water temperature sensor monitors the temperature of the water entering the boiler sections. The sensor sends this information to the IBC. The IBC determines how much to adjust the circulator flow rates to provide at least 140°F water to the cast iron heat exchanger.

LEGEND

a Supply to system, 1” NPT
b Return from system, 1” NPT
c Combustion air inlet fitting — 3” PVC connection
d Flue outlet — 3” PVC connection
e Gas valve — negative pressure regulated gas control
f Pressure/temperature gauge
g Flue way inspection port cover
h Sensor hose trap
i Manual air vent
j Relief valve
k Thermal switch — a device that shuts the boiler off if flue temperature exceeds its setpoint
m Condensate trap — shipped loose with boiler, field installed

WARNING

This boiler uses a negative-pressure-regulated gas valve, set for an outlet pressure of approximately –0.20” water column.
DO NOT set the outlet pressure higher than the factory setting.

GV90+ Series 2 Water Boiler

Operating instructions

WARNING

Before attempting to start the boiler, check the boiler pressure temperature gauge. If the boiler and system are full of water and properly pressurized, the gauge should read at least 12 psig on most systems. Operating the boiler without proper water content will damage the boiler and controls and could result in severe personal injury, death or substantial property damage

Figure 5 Operating instructions

FOR YOUR SAFETY – READ BEFORE

WARNING

If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or loss of life.

A. This appliance does not have a pilot. It is equipped with an ignition device that automatically lights the burner. Do not try to light the burner by hand.
B. Before OPERATING, smell all around the appliance area for gas. Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor. See below.

C. Use only your hand to turn the gas control knob. Never use equipped with an ignition device which tools. It the knob will not turn by hand, don’t try to repair it automatically lights the burner. Do not try to call a qualified service technician. Force or attempt to light the burner by hand. repair may result in a fire or explosion.
D. Domediately is la Dania service he nician to inster to the floor because some gas is heavier than the appliance and to replace any part of the control system air and will settle on the floor. See be low. and any gas control. which has been underwater.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance. Foote aspers studion som a neighbor’s phone Done in your electrical switch; do not use any
• If you cannot reach your gas supplier, call the fire department.

OPERATING INSTRUCTIONS

1. STOP! Read the safety information above on this label. This appliance is equipped with an ignition device that automatically lights the burner. Do not try to light the burner by hand.
2. Set room thermostat(s) to the lowest setting.
3. Turn OFF all electrical power to the appliance.
4. Locate the boiler manual gas valve (in the gas piping connected to the boiler).
5. Turn the boiler manual gas valve knob counterclockwise to OPEN gas supply.
6. Wait five (5) minutes to clear out any gas. Then smell for gas, including near the floor.
7. If you smell gas, STOP! Turn the boiler manual gas valve to OFF. Then follow WHAT TO DO IF YOU SMELL GAS, above. If you don’t smell gas, go to step 8, below.
8. Turn ON all electrical power to the appliance.
9. Set thermostat(s) to the desired setting.
10. The boiler display will show symbols and/or text describing the status of the boiler as it proceeds through its operating sequence. “Standby” status means the burner is off.
11. If the appliance will not operate when there is a call for heat and the piping is not hot, follow the instructions “To Turn Off Gas To Appliance” below and call your service technician or gas supplier.

Gas valve CLOSED

TO TURN OFF THE GAS TO THE APPLIANCE

1. Set room thermostats to the lowest setting.
2. Turn OFF all electrical power to the appliance. clockwise to close gas supply.
3. Turn the boiler manual gas valve knob clockwise to close gas supply.

Common problems and solutions

Rapid cycling — boiler turns

on and off frequently

| Thermostat was installed where drafts

or heat affect reading

| Locate the thermostat on inner wall away from heat sources or cool drafts.

Heat anticipator in thermostat adjusted incorrectly

| ****

Adjust the thermostat per the manufacturer’s instructions.

Incorrect boiler temperature setting| Set boiler temperature according to system needs. Maximum setting is 200°F. Increase boiler temperature setting to decrease cycling.
Insufficient water flow through

boiler

| ****

Check all valves to and from the boiler. Return to the proper setting.

Confirm circulator size.

Frequent release of water

through relief valve

| Expansion tank sized too small| Call a qualified service technician to check the expansion tank operation and size.
Flooded expansion tank| Call a qualified service technician to check

expansion tank operation.

Inoperative limit control| Call a qualified service technician to replace

limit control.

Need to frequently add

makeup water

| Leaks in boiler or piping| Have qualified service technicians repair leaks at once to avoid the constant use of makeup water. Makeup water can cause mineral deposits which, in turn, can cause boiler section failure. Do not use petroleum-based stop-leak compounds.
**Black water condition| ** Oxygen corrosion due to leaks in boiler and piping| ** Have qualified service technician repair at once. Keep pH of water between 7.0 to 8.5.
Large temperature swings in living space| ** Incorrect Economy setting| Adjust the Economy setting on boiler control.
Symptom| Common Causes| Possible Corrections
---|---|---
Popping or percolating noise heard in boiler| Mineral deposits in sections due to constant use of makeup water| Call a qualified service technician to de- the boiler, if necessary. In some cases, deposits will be too heavy to remove with de-limiting procedures.
Have qualified service technicians repair leaks to eliminate need for constant makeup water.
Incorrect pH of boiler water| Call qualified service technician to check pH level and correct. pH should be maintained between 7.0 to 8.5.
Insufficient water flow through

boiler

| Check all valves to and from boiler. Return to proper setting.
Confirm circulator size.
Metal flakes found in vent outlet or vent starter tee — flue way corrosion| Contaminated combustion air supply — See page 4 in this manual.| Remove any contaminating products. See page 4 in this manual.
Provide outside air for combustion. Have

a qualified service technician pipe-up kit.

Condensation of combustion gases in boiler sections| Have a qualified service technician check the operation of mixing system. Repair/ replace if necessary.
Some radiators or baseboard units do not heat or are noisy| Air in system| Bleed air from system through air vents in radiators or baseboard units.
Low system pressure| Fill to correct pressure.
Check for leaks in the boiler or piping. Have

qualified service technician repair at once.

Boiler temperature set too low| Adjust boiler temperature to a higher setting.

WM Technologies, LLC
500 Blaine Street
Michigan City, IN 46360-2388
weil-mclain.com

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