If your furnace starts but it doesn't make heat, a number of things could be wrong, and one of them is a faulty gas valve. The gas valve inside your furnace allows gas from the gas line to enter the furnace so it can ignite. When the thermostat signals the furnace to turn on, the control board sends power to the ignitor, gas valve, and flame sensor.
The ignitor heats up to light the gas released by the valve and the flame sensor checks that the gas lights. If something is wrong with the gas valve, the normal sequence of starting the furnace doesn't take place. Instead, there is no flame and no heat. Here are some things that can go wrong with the gas valve and how a bad valve is replaced.
What Can Go Wrong With A Gas Valve
A gas valve can malfunction if it goes bad, but it can also malfunction for other reasons. The control board may not be sending the valve power, the solenoid might be bad, or wiring might be loose. If any of those are the problem, the furnace repair technician can replace them and see if the gas valve starts working again.
The furnace repair technician can use a multimeter to test for power going into and out of the valve. If power goes in but not out, then the valve is bad. A bad gas valve has to be replaced rather than repaired for safety reasons.
How A Bad Furnace Gas Valve Is Replaced
Furnaces differ, but the gas valve should be in a location that's easy to see and reach since it connects to the gas pipe that supplies gas to the furnace. First, the repair technician turns off the gas and electricity to the furnace. Then they can locate the gas valve and disconnect it.
The valve has wiring attached that has to be removed. There are also two pipes attached to the valve. One is the gas line pipe, and the other is on the opposite side and is the manifold pipe. These pipes have to be unthreaded to free the valve.
Next, a new valve is put in, attached to the wiring, and connected to the pipes. The valve assembly is secured to the furnace with screws and tested to make sure it works properly and helps the flame to ignite and create heat. The gas valve is an important part of your furnace, and since it controls the release of gas, call a furnace repair company if you think the valve might be bad or if your furnace starts and won't heat. Look for a local company like Powder River Heating & Air Conditioning Inc.