Gas Heater Repair

If you are looking for gas heater repair guidelines, you need not look any further. In this article, I provide an overview of how to repair these types of heaters, by highlighting solutions to most common problems.
Gas heaters or gas furnaces are some of the most efficient heating systems, that one can opt for. Like every appliance, they come with their share of problems. A dysfunctional heater can literally let your assets get frozen in winter.


The working is quite simple to understand in principle. A gas heater takes in cold air, filters it and then heats it by usage of a steel heat exchanger fitted with a gas burner. Then the hot air is blown away by the usage of a blower motor into the duct network. These ducts transport the hot air throughout your house. There is a feedback mechanism that takes the cold air back in through return air grills and is transported back through the duct work. There is an elaborate ignition and temperature control mechanism inside the main heater core which uses thermostats.

Repair Guidelines

It will be useful to have your gas heater manual with you while beginning troubleshooting, as it will have all the required technical information.

Heater Supplies Insufficient Or No Heat
This is the most common problem and it can be caused by either a thermostat failure, low temperature setting of thermostat, blown fuse, closing of natural gas valve inlet or pilot light failure.

How to Fix It?
If it's a faulty thermostat that is the culprit or you notice a blown fuse, then replace them immediately. In case the heater has stopped working, due to a tripped circuit breaker, reset it. If the heating is insufficient, raise the temperature dial that sets the thermostat heating limit. Another reason for insufficient heat supplied may be a clogged filter which may need cleaning or replacement.

Heater Intermittently Switches On and Off
The reasons for this kind of a problem can be many. One of the reason might be a problem with the heat anticipatory system of the thermostat or a problem with the blower motor. Other than these main causes, a clogged air filter might also be the culprit.

How to Fix It?
You will have to adjust the heat anticipatory system of the thermostat, if that's causing problems. If the blower motor of the heater is the culprit, then ensure proper lubrication, and adjust belt tension to make it work smoothly. Replace the belt, in case it is too frayed.

Blower Doesn't Turn Off
The reason for this might be that the thermostat has been set to 'fan continuous' option among the various settings. In case, the thermostat has no fan setting, then the fan limit control switch might be the culprit.

How to Fix It?
If it's because of the fan setting just change it, to solve the problem. If the switch is the problem, then either replace it or reset it.

Heater Pilot Goes Out
The reasons for a pilot going out could be many. It may be caused by a strong air draft, gas tube clogging, clogged orifice or a faulty thermocouple.

How to Fix It?
You may need to clean the gas tube, for which you might need assistance from professionals. If it's the thermocouple that's causing the problem, just replace it.

These were some of the most common gas heater problems that crop up. Fixing them on your own can save substantial amount of money, as repair costs are high. If the problem is beyond your understanding and you are not sure about what to do, its best to handover the job to a professional.
By Omkar Phatak
Published: 4/28/2010
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