Laars mascot ft MFTHW

Questions and Answers

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David BarronAug 19, 2025
What to do if Laars mascot ft MFTHW burner does not ignite when hot water is opened?
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  Donald StoutAug 19, 2025
  If the burner on your Laars Boiler doesn't ignite when you open the hot water tap, there are several things to check: * Ensure the ON/OFF button on the Control Display is turned ON. * If the Control Display is blank, verify the power cord is plugged in and the 4A fuses on the main controller are intact. * Confirm that water is being supplied to the unit, as it activates when the inlet water flow exceeds 0 gpm. * Check that the cold and hot water lines are correctly plumbed and not reversed. * Make sure both the cold water and gas supply lines are open. * Ensure the water lines are not frozen.
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Scott FoxAug 21, 2025
Why is the water from my Laars Boiler not hot enough?
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  Kevin WilliamsAug 21, 2025
  If the water from your Laars Boiler isn't hot enough, consider the following: * Check the temperature setting on the unit to ensure it's not set too low. * Inspect the filter in the cold water supply line for clogs from debris. * Verify that the gas supply type is correct for your unit. * Ensure the supply and manifold gas pressures align with the specified requirements. * Confirm the water flow sensor, which has three wires, is properly connected on top of the heat exchanger.
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Kevin PayneAug 23, 2025
What to do if water is too hot in Laars Boiler?
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  Sarah AlexanderAug 25, 2025
  If the water from your Laars Boiler is too hot, take these steps: * Verify that the temperature setting on the unit is not set too high. * Check the filter in the cold water supply line to ensure it's free of debris. * Confirm that the gas supply type being used is correct for the unit.
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Jason KellyAug 26, 2025
Why does my Laars mascot ft MFTHW make abnormal sounds during operation?
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  Elizabeth ChurchAug 26, 2025
  Abnormal sounds from your Laars Boiler during operation can be due to several reasons: * A leak of combustion gas between the sealed chamber and exhaust tube inside the unit. * Improper venting termination. * Insufficient gas pressure, which can cause an unstable burner flame and noise. Make sure that the venting termination complies with specifications and check the supply gas pressure is sufficient. If there is a leak of combustion gas, call a qualified service technician for evaluation.
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Ronald TurnerAug 28, 2025
Why does the hot water temperature fluctuate in my Laars mascot ft MFTHW Boiler?
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  Ashley WilkersonAug 28, 2025
  If the hot water temperature from your Laars Boiler fluctuates at the tap, consider these factors: * Ensure the filter in the cold water supply line is clean. * Verify the gas supply type is correct. * Check that the supply gas pressure is sufficient.
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Jamie TuckerAug 30, 2025
What to do if Laars mascot ft MFTHW is operating but nothing is shown on the control display?
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  Jason CraigAug 30, 2025
  If your Laars Boiler is operating but the Control Display shows nothing, the issue might be: * Lost communication from the control to the display. Check for loose connections and proper pin alignment/engagement on the Control's plug. You can also try cycling the power off and on using the boiler power switch to see if the display starts working again.
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Robert FletcherSep 2, 2025
Why is my Laars mascot ft MFTHW blower running at full speed with nothing on the display?
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  Mr. Chase CoxSep 2, 2025
  If the Control Display of your Laars Boiler shows nothing and the blower is running at full speed, it could indicate: * The control is not receiving power. Check the wiring for any short circuits or incorrect connections. Also, check the transformer connection to the control, referring to the wiring diagram, and ensure there is a 12V output from the transformer.
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lukeatkinsonSep 4, 2025
What causes Laars Boiler temperature to rise too quickly?
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  Charles GriffinSep 4, 2025
  A rapid temperature increase in your Laars Boiler occurs when the supply water temperature in the heat exchanger rises faster than 2°F per second during the first two minutes the burner is on. This issue usually resolves itself after a short delay, or you can manually reset it on the Control Display. Look for a message related to the TEMPERATURE SENSOR and follow the instructions for checking loose connections.
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Nicole KingSep 6, 2025
What does BLOWER FAULT mean on my Laars mascot ft MFTHW?
- O
  obassSep 6, 2025
  A BLOWER FAULT on your Laars Boiler indicates that the blower is either unable to reach the required speed or does not reach 0 RPM when turned off. To resolve this, reset the system using the manual reset screen on the Control Display.
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Donna PotterSep 8, 2025
Why is the Laars mascot ft MFTHW blower still operating after combustion stops?
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  Valerie CarlsonSep 8, 2025
  It's normal for the blower in your Laars Boiler to continue running for about 1 minute after combustion stops. This allows it to vent (exhaust) the flue gas from the chamber.

Summary

Section 1 Product Accessories

Section 2 Product Characteristics

2.2 Specifications, 80 MBH and 100 MBH

Details technical specifications for 80 and 100 MBH models.

2.2 Specifications, 125 MBH and 140 MBH

Details technical specifications for 125 and 140 MBH models.

2.2 Specifications, 199 MBH

Details technical specifications for the 199 MBH model.

2.4 Names of Components (80;100 MBH)

Identifies and labels internal components for 80/100 MBH boilers.

2.4 Names of Components (120;140 MBH)

Identifies and labels internal components for 120/140 MBH boilers.

2.4 Names of Components (199 MBH)

Identifies and labels internal components for the 199 MBH boiler.

Section 3 Safety Regulations

3.2 Safety Precautions and Proper Use

Details crucial safety practices before, during, and after boiler operation.

Section 4 Installation

4.1 Location and Clearances

4.3 Combustion Air

4.4 Venting (Exhaust)

4.6.1 Direct Venting Clearances

4.6.2 Non-Direct Venting Clearances

4.9 Gas Supply and Piping

Covers requirements for gas supply lines, sizing, and installation.

4.10 Gas Supply Pressure

4.11 Gas Setup and Adjustment

4.12 High Altitude Installations and Orifices

4.13 Natural Gas to Propane Conversion

Details the process and parts required for converting the boiler from natural gas to propane.

4.14 Plumbing Guidelines

Covers external plumbing and water connection requirements.

4.15 Pressure Relief Valve

Details the installation and requirements for pressure relief valves.

4.16 Disposal of Condensate

Explains how to properly drain and dispose of boiler condensate.

4.17 Electrical Wiring Connections

Provides instructions for making electrical connections to the boiler.

4.18 DIP Switches

4.19 Control Board, Electrical Diagram

Shows the wiring diagram for the boiler's control board.

4.20 Ladder Diagram

Presents a ladder logic diagram illustrating the boiler's control system.

4.21 Electrical Connections

Details electrical connector pin assignments and their functions.

Section 5 Control Display and Operation

5.1 Control Dial and Buttons

5.2 LCD Overview

5.3 Operating Mode

5.5 CH Set Point Change Mode

5.6 Status display mode

5.7 Installer Mode

Outlines the installer mode for adjusting advanced parameters and settings.

5.8 Storage Mode; Indirect Water Heater

5.9 Outdoor Reset Adjustment

5.10 External Set Point Temperature Control

5.11 Error Mode

Shows how the control display indicates and reports error conditions.

Section 6 Error Codes

6.1 Error Codes

Details specific error codes, their descriptions, and potential solutions.

6.2 Fault Tree Analysis

Provides diagnostic flowcharts for identifying and resolving flame detection issues.

Section 7 Trouble Shooting

7.1 Diagnostics

7.2 Suggested Corrective Actions

Section 8 Maintenance

8.1 Annual startup & general maintenance

8.2 Flushing the Boiler

Section 9 Installation Check

9.2 Final Check Lists

Laars mascot ft MFTHW Specifications

General

Category	Boiler
Brand	Laars
Model	Mascot FT MFTHW
Fuel Type	Natural Gas or Propane
Modulating Burner	Yes
Heat Exchanger Material	Stainless Steel
Thermal Efficiency	95%
Efficiency	Up to 95%
Vent Diameter	Varies by model