Now that the cold weather of fall has arrived, your home's gas wall heater needs to be functioning at its best. While gas-powered wall heaters are fairly simple appliances and tend to be very reliable, they are prone to a few common mechanical problems. One of the most frequent issues is a thermostat that only intermittently turns the system on.
If you've noticed that it's become necessary to fiddle with the thermostat to get the heater to turn on, then this is typically a simple problem you can fix without having to call an HVAC technician.
To repair the gas wall heater, follow these simple steps:
Step 1: If the Thermostat Has Batteries, Change Them
Before you delve any farther into repairing your heater, it's important to start with the simple things that often go awry. If your heater has a thermostat with batteries, then simply change them out with a fresh pair. Sometimes, even if the "change battery" light isn't on, low batteries can still cause problems with a thermostat's operation.
Step 2: Check the Status and Flame Quality of the Pilot Light
As with battery issues, sometimes gas wall heaters have problems with their pilot light generator or thermocouple. To ensure both of these parts are working correctly, all you need to do is take a good look at the pilot light and its flame quality. If the pilot light is burning strong, then it's almost guaranteed that the problem you are encountering is with the wall thermostat and not one of the internal parts.
Step 3: Remove the Wall Thermostat
The thermostat on your wall has a black and a white wire connected to it. The other end of these wires is inside the heater connected to the thermocouple. These wires do not have any electrical power, and it is safe for you to remove them from the thermostat by unscrewing each connection you see.
Step 4: Test the Wiring at the Thermostat Location
If you touch the end of the black wire to the end of the white wire, then the heater should come on. If you test the wires and the heater doesn't come on, then you need to call an HVAC technician out to replace them. If the heater does come on, then you can be sure the problem is a faulty thermostat.
Step 5: Replace the Wall Thermostat
To replace a faulty thermostat, simply trim off a couple of inches of the wire. Strip back the wires to expose some bare wire, and then attach one wire on each contact on the new thermostat.
Check to make sure the thermostat is now reliably turning your gas wall heater on and off. If so, then you have solved the problem! If not, then it's time to call a professional for heating services.