You can carry out many types of gas boiler repair yourself. More complex repairs will require professional help, but some common problems are fairly simple to fix. Learn more about these common problems below.
When no heat comes from the boiler, there could be several potential causes. First you should check the circuit breaker (or fuse). If it is in the "Off" position, switch it to "On" and try the furnace again. In the case of a damaged fuse, you will need to replace it.
If the pilot light has gone out, activate it by following the instructions on the boiler. Make sure the thermostat is in "Heat" mode and turn the thermostat up a few degrees to see if the boiler kicks in. Check the water in the boiler. It should be half full and between 12 to 15 PSI. You can adjust it with the pressure-reducing valve. If your unit doesn't have a pressure-reducing valve, open the water-feed valve until the pressure is set at 12 PSI.
If you suddenly find inadequate heat coming from the boiler, the problem will inevitably be low pressure in the boiler. You can read the boiler pressure reading on the tridicator. If the level is under 12 PSI, the boiler needs more water. In most cases, the pressure-reducing valve will rectify this automatically. If you don't have a pressure-reducing valve, follow the directions in the previous section.
Where there’s been a gradual reduction in heat over a period of time, it’s a good sign that the boiler needs to be flushed. You can do this yourself.
If you find water around the boiler, the problem will be due to a leaking connection in the pipes, a faulty pump or a faulty pressure-relief valve. Where the pump is the cause of the leak, you can carry out a simple gas boiler repair that requires the removal of the pump and a new pump seal.
If the pressure-relief valve is at fault, try turning off the boiler until the water cools. Open the manual pressure-relief valve for 3 seconds and allow some water to discharge. If the valve continues to leak afterward, open it again to let any trapped sediment flow out. If the valve will not close, you will need a more complex gas boiler repair to replace the valve. If no water appears when you open the valve, you'll know the valve is plugged and must be replaced. (Check that there is water in the boiler before doing this.)
Especially noisy pipes may result from water in the return lines or a faulty circulator pump. If water is trapped in the return lines, it will usually happen because the line is no longer pitched down toward the boiler. You can rectify this condition with a simple gas boiler repair; you can use a pipe hanger to change the angle.
If the problem is in the circulator pump, check for a broken spring-loaded coupling that connects the pump to the motor.