Gas furnaces use either propane or natural gas to heat enclosed living areas. While gas is often talked about as an expensive means of heat, gas furnaces typically burn cleaner than oil furnaces and therefore present their owners with less repairs than oil furnaces. But when problems do occur with gas furnaces, they're typically easy to identify and aren't labor intensive to correct. Below are four issues that commonly arise with older gas furnaces and what you can expect in terms of repairs.
A Furnace Produces No Heat
If your gas furnace produces no heat, chances are that it's experiencing one of the following issues: a closed control valve, a blown fuse or tripped circuit, a faulty thermostat or a non-working pilot light. While you could correct these problems yourself, it's best to call a gas furnaces repair service (i.e. a heating and cooling company) if you aren't experienced with gas furnaces. Regardless of which of the above issues your furnace is experiencing, an HVAC repair technician should be able to fix the problem on the same day, and none of the above issues will result in a significant repair cost.
A Furnace Produces Insufficient Heat
If your furnace has been producing less heat, it could be because the blower is occluded, the blower belt is loose or because the filter or burner is dirty. These problems can also occur in unison. As with a furnace that produces no heat, a furnace that produces insufficient heat resulting from one of the above issues can usually be fixed on the same day at minimal cost. If a gas furnaces repair technician indicates that the problem stems from one of the above issues but that some of the other issues appear immanent, save money and have all of them repaired in one visit.
A Furnace Keeps Switching On and Off
If your furnace switches on and then switches off before producing the desired level of heat, it likely suffers from one of the following problems: a clogged blower, a dirty filter or an overly dry motor. In the first case, a technician will clean out your blower and its surrounding area using a vacuum; in the second case, the technician will replace your temporary air filter or clean and reinsert your permanent air filter; in the third case, the technician will lubricate the motor by placing oil in the necessary oil ports. In each case, the service cost should again be minimal.
A Furnace's Pilot Light Won't Come On
With most furnaces, you can tell if a pilot light is on by kneeling to the floor and looking at the underside of the furnace, where you'll see a small blue flame emanating from a small pipe if the pilot light is running. A pilot light that won't light is generally caused by one of three issues: a clogged pilot opening, insufficient gas flow due to an improperly set gas valve or a damaged thermocouple. In each case, the remedy is requires light labor and can be fixed at minimal cost.
As a gas furnace repair technician for a large HVAC company, most of the gas furnace problems that I encounter are easy to fix and can be fixed at minimal cost to the homeowner. But it's always important for those who aren't experienced with gas furnaces to leave even minimal repair work to the professionals, especially considering the danger of creating a gas leak.