LAARS MFTCW199 High Efficiency Wall Mount Combi Boiler User Manual

: June 6, 2024
: LAARS

MFTCW199 High Efficiency Wall Mount Combi Boiler

User’s Manual

THE FT SERIES
Wall-Mounted, Modulating Gas, Condensing, Combination Boiler Model FTCW
140,000 BTU/h 199,000 BTU/h

Natural Gas (NG) – Factory Configuration
Propane Gas (LP) – Field-Convertible

FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician, qualified in hot water boiler and heater installation and maintenance. Improper installation and/or operation could create carbon monoxide gas in flue gases which could cause serious injury, property damage, or death. Improper installation and/or operation will void the warranty.

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 phone in your building.
Immediately call your gas supplier from a nearby phone. Follow the gas supplier’s instructions.
If you cannot reach your gas supplier, call the fire department.

Installation and service must be performed by a qualified installer, service agency, or gas supplier.

1. Familiarizing yourself to the FT SERIES

The FT Series Combi is a wall mounted, condensing and fully modulating, residential boiler and water heater.

This User’s Manual will guide you into the basics of operating your FT Series Combi.

Please reference the Installation and Operation Manual for complete details. Doc# 1487

2. Caring For Your FT

Your FT Series Combi will require very little maintenance. However, as with any fine appliance there are certain steps that should be taken to ensure continuing optimum performance.

2.1 General Care

Keep the area around the FT Series Combi clean and free from combustible materials, gasoline and other flammable liquids and vapors.
The FT Series Combi must be completely isolated and protected from any source of corrosive chemical fumes such as trichlorethylene, perchlorethylene, chlorine, etc.
Keep bottom and top openings on the boiler free for proper ventilation of interior components.
Do not obstruct or block a free flow of air to the boiler to ensure proper ventilation.
If desired, clean the jacket surfaces with a damp cloth and mild detergent. Do not use flammable cleaning materials.
If sidewall vented, keep the vent terminal clear of obstructions — do not allow snow to cover the vent terminal. Clean the intake screen often, and then develop an appropriate maintenance schedule.

2.2 Annual Inspection of Flue and Vents

Visually inspect the vent pipe once a year. Should any deterioration exist, have the affected parts replaced by a qualified service person.

2.3 In the Event of a Power Failure

The FT Series Combi can not be operated during an electrical power outage. If there is an extended power outage with danger from freezing, then the FT Series Combi (and all other water systems) should be drained completely. When draining the boiler, turn off main electrical disconnect switch. When placing back in service, refer to Section 3 of this Manual for instruction. All draining and filling must only be done by a qualified service person.

2.4 Full Service Every Year

In addition to the annual visual inspections, a qualified service agency should conduct a detailed inspection of all flue product carrying areas of the FT Series Combi and its venting system.

User’s Manual – The FT Series Wall Mounted, Combination Boiler

combination boiler

Name of Component

Air Vent (air eliminator)
Pressure Relief Valve
Air Intake Collar
Air Gas Mixing Pipe
Gas Valve
DHW Water Tank
Main PCB
Manual Power Switch (ON / OFF)
Boiler Pump
‘CH’ Supply Connection
‘CH’ Return Connection
CH Pressure Gauge
DHW Outlet Connection
Gas Inlet Connection
DHW Inlet Connection (filter and flow restrictor)
Condensate Connection
Condensate Trap
Blocked Condensate Switch
Mixing Valve
Terminal Block
Control Panel and Display
Heat Exchanger
Ignition Transformer
Flame Detecting Sensor
Burner Case
BLDC Fan (Blower)
Vent Pipe
Air Pressure Sensor
Vent Pipe Collar
Sight Glass
Low Water Cut Off
Overheat Temperature Sensor

3. Shut Down and Restart

3.1 To Start the FT Series Combi
If drained, please refer to the Install and Operating

3.2 Shutting Down the FT Series Combi

1. Turn off the main electrical disconnect switch.
2. Close all manual gas valves.
3. If freezing is anticipated, drain the FT Series
Combi and be sure to also protect building piping
from freezing. All water must be removed from
heat exchanger and condensate trap or else
damage from freezing may occur. Please refer to
the Install and Operating Manual.
This step to be performed by a qualified service person.

4. The Control Display and Operation

control panel

The Control Display has a Control Dial (E), 4 buttons (A, B, C, D), and a Liquid Crystal Display (with 72 back-lit segments). This section of this manual gives instruction on how to navigate into the many functions of the FT and to change temperature set points, set system variables and controller parameters.

Buttons

|

Function

|

Method

|

Function

|

Method

---|---|---|---|---

A

|

Display Power

|

Turns Control Display ON / OFF

|

Press/Tap

|

B

|

Modes

|

Status Display Mode (With display power on)

|

Press/Hold (5 Seconds)

|

Return to Menu (from Status Display Mode)

|

Press/Tap

Installer Mode (WIth display power off )

|

Press/Hold (5 Seconds)

|

Return to off display off mode (from installer mode)

|

Press/Tap

C

|

Hot

Water

|

DHW Set point LOW Range

95 – 120°F (35 – 49°C)

|

Press/Tap (To return home, tap Scroll/Select)

|

DHW set point HIGH

Range 121-140°F (49.5- 60°C) (from DHW set point LOW RANGE)

|

Press/Hold (5 Sec onds), (To return home, tap Scroll/Select)

D

|

Central

Heat

|

CH set point mode (boiler only)

|

Press/Tap (To return home, tap Scroll/Select)

|

Toggle (°C/°F) (from CH set point mode)

|

Press/Hold (5

Seconds)

E

|

Scroll /

Select

|

Turn to scroll (clockwise or counterclockwise), Tap to select

|

Press/Tap

|

Temperature Specifications Operating ambient Temperature Range : -10 to 60°C. Operating Relative Humidity up to: 90% at 40°C. Shipping & Storage Temperature Range of : -20 to 80°C.

User’s Manual – The FT Series Wall Mounted, Combination Boiler

4. The Control Display and Operation (continued)

control display

CH mode

|

Central Heat mode icon can be adjusted

---|---

Anti-freeze mode

|

Anti-freeze mode icon

Storage Heating mode

|

Stored Water Being Heated, can be adjusted

Lock mode

|

Buttons-locked mode icon

Communication

|

Communication icon

Summer mode

|

Only DHW Mode, can be adjusted (warm weather shutdown)

Status and Installer mode

|

The Status Mode or the Installer Mode is Active (all parameters)

Flame signal

|

Flame Signal icon

Pump icon

|

Water pump operation (CH or DHW) icon

Numeric Display

|

Number and character display, to display all parameters

DHW mode

|

Combination boiler Set Point, can be adjusted

Outside temp or 0-10 V mode

|

Operating by outside temperature or 0-10V

The LCD will illuminate when a user action is detected (a button is pressed) and will turn back off after 20 seconds.

NOTE: The display will not allow changes when the lock mode To exit the Lock mode, press the button.

is activated.

WARNING
Do no use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control that may have been under water.

5.3 Operating Mode

Operating Mode After the Power is turned on, and/or the Control Display is turned on , the Control Display will go through a Start Up’ checklist and briefly show a sequence of diagnostic codes before entering into the Operating Mode. It will then display the following information.

operation mode

indicate

Status Display Mode

display parameter

To view any of the above listed Status Parameters,
Press and Hold Button B to get into the Status Display Mode.
Rotate Dial E until you find the Parameter that you wish to view. Tap Dial E to enter that Parameter.
Adjust to the setting that you require and then press (tap) Dial E to save and to Exit.

5.5 DHW Set Point Change Mode

DHW Set Point Change Modes The display shows the following information when changing water heating temperature set points.
Changing between Celsius and Fahrenheit When the button D is pressed (for more than 5 seconds), temperature unit will toggle between °C and °F.

Indicate Example
Current DHW set point temperature 120°F
Temperature sign Celsius or Fahrenheit letter °C or °F
If display is communicating with the main controller normally, the
communication icon will be indicated.
When DHW set point range is high : from 121°F (49.5°C) to 140°F (60.0°C) H . 140°F
When changing DHW set point, the DHW icon will fl ash S24

Example 120°F °C or °F
H . 140°F S24

* Default DHW set point is 120°F (49°C)

DHW 95-120°F (35 – 49°C) LOW range (Default) -To change LOW range, press the C Button. The DHW icon and current DHW LOW will flash (a flashing
value means it can be changed). -Turn dial E clockwise to increase and counterclockwise to decrease until desired temperature is reached. -Press dial E to save set point changes.
DHW 121 – 140°F (49.5 – 60°C) HIGH range -To change HIGH range, press and HOLD the C button for more than 5 seconds. The DHW icon and
current DHW HIGH will flash (a flashing value means it can be changed). -Turn dial E clockwise to increase and counterclockwise to decrease until desired temperature is reached. -Press dial E to save set point changes and to Exit.

DANGER

Scalding may occur within 5 seconds at a setting of 140°F (60°C). Water temperatures over 125°F can cause severe burns, or death from scalding. Children, disabled, and elderly are at highest risk of being scalded. Read all instructions before setting temperature at appliance. Feel water before bathing or showering.
Manufacturer strongly recommends the use of an anti-scald mixing valve at domestic hot water outlet (boiler location) to reduce potential for scalding. Contact Manufacturer for recommended models. Check with local codes.

User’s Manual – The FT Series Wall Mounted, Combination Boiler

5.6 CH Set Point Change Mode

Changing between Celsius and Fahrenheit
When the button D is pressed (for more than 5 seconds), temperature unit will toggle between °C and °F.

temp mode

Default CH set point is 130°F (54°C) CH set point range is 130 – 180°F (54.4 ~ 82.0°C)
To change CH Set point, press the D button. The CH Icon and current
CH Set point will flash. Turn the E dial clockwise to increase, and counterclockwise to decrease CH set point, until
desired temperature is reached. Press E dial to save changes and to Exit.

5.7 Storage Mode

To activate heat storage function, First turn OFF the power to the Control Display.
Then Press and Hold Button B to get into the Installer Mode. Rotate Dial E until you find 5:St Tap Dial E to enter Storage Mode. Storage Mode indicates that the boiler is
maintaining the water temperature in the internal storage tank. When Storage Mode is active, the display will appear as shown. Turn the E dial clockwise to activate and counterclockwise to deactivate the Heat storage function. Default: ON. Press E dial to save changes and to Exit.

User’s Manual – The FT Series Wall Mounted, Combination Boiler Notes:

Page 11

User’s Manual – The FT Series Wall Mounted, Combination Boiler

H2412500-

Dimensions and specifications subject to change without notice in accordance with our policy of continuous product improvement.

Customer Service and Product Support: 800.900.9276 · Fax 800.559.1583 20 Industrial Way, Rochester, NH, USA 03867

20-10 Document 1488