Tuesday, 24 May 2016

How to troubleshoot a gas furnace?

A gas furnace is a piece of equipment that takes in cold air, uses an air filter to clean it, heats it with the help of a gas burner and distributes the warm air through the ductwork. The heated air helps to increase room temperature during the cold winter days. Furnaces come with different efficiencies. However, once in a while these appliances may not work quite right and you may have to troubleshoot them. 

Let's look at the most common problems you may have to face with a conventional furnace.

Gas Furnace does not produce any heat:

Possible causes:

  1. Thermostat not working
  2. Propane or natural gas control valve is closed
  3. Circuit breaker or fuse that is controlling the gas furnace is tripped or blown
Best possible repairs:

  1. Check if the thermostat has the right temperature setting
  2. Try to move the dial setting down or up a few degrees
  3. Clean contacts in a non-digital thermostat
  4. If the circuit breaker has tripped, reset it
  5. Relight the standing pilot light
Blower is always running:  
Possible causes:

  1. Thermostat has been fixed to run fan continuously
  2. Defective control switch for fan limit
Best possible repairs:

  1. Change the fan setting on the thermostat
  2. Replace or reset furnace fan control switch
Gas furnace produces less heat

Possible causes:

  1. The air filter is dirty
  2. The gas burner is dirty or requires adjustment
  3. Air flow is blocked to the combustion air chamber
Best possible repairs:

  1. Clean or replace the dirty air filter
  2. Call a professional service provider to get the burners adjusted.
  3. Make sure the furnace has enough combustion air.
Noisy operation of gas furnace

Possible causes:

  1. A "squealing" sound caused by slipping motor or shaft bearings or blower belt that requires oiling
  2. Slight "rumble" when the burner is off may be caused due to wrongly adjusted pilot light.
  3. Slight "rumble" sound when the burner is on is caused by dirty gas burners.
Best possible repairs:

  1. Use a light weight oil to lubricate the blower motor lubrication ports located at the end of the shaft
  2. Check for correct belt tension. If it’s loose, make sure you tighten the belt.
  3. Adjust pilot light
  4. Replace frayed belt
  5. Call a technician to get the burners cleaned or adjusted.
Pilot light is out

Possible causes:

  1. Dirty orifice, a strong draft, or dirt inside the gas tube can lead to a pilot light going out.
  2. A faulty thermocouple may also shut off the supply of gas.
Best possible repairs:

  1. Ensure that your thermostat is on "Heat" mode.
  2. Find the pilot.
  3. In case you have a pilot that has a red Reset button, turn "Off," the gas valve to "Pilot."
  4. In case you have a pilot that has no red button, turn the dial from "Off" to "Pilot."
  5. Depress the knob or hold the button and light the pilot using a lighter.
  6. After the furnace burners ignite, regulate the thermostat to the preferred setting.
Sometimes your gas furnace may act out and may require repair. You can follow the tips mentioned above or call a technician to fix the problem. If the issue seems complicated, it is best to seek professional help.