Why Your Boiler Keeps Locking Out

A boiler and other appliances in a garage.

Running a boiler is not usually a difficult business, but as your hot water system ages, you may find that it begins to develop problems which are annoying, inconvenient, or actually hinder you in getting hot water. If your boiler begins to lock out, or is not heating up the water when required, then you may have one of a number of problems which could be the cause of your boiler's failure to heat.

Check the Boiler for Heat

When you have been experiencing a lot of boiler lock outs, then you should start examining the tanks. Place your hand upon the boiler case, and see whether it is actually hot. If there is no heat in the boiler, then you may have a problem with your valves, or with the energy supply. Check the valves to see whether they are locked into an off position. If it seems like a problem with the energy being supplied to your boiler, then you will need to call a professional. A boiler locking out should be covered by your insurance, but if it is not, it might require a costly repair.

Check for Electrical Failure

If your boiler keeps locking out, it may be receiving a faulty high temperature reading from one of the gauges. Examine these, and look for signs of loose wires, faulty readings, or blown fuses. You may have to take the entire gauge away and replace it before the boiler begins to work again. If your boiler is not hot, but a new temperature gauge also gives a high reading, this is a sign that the inside of the boiler has become corroded, so you will need to call a boiler engineer to have this fixed.

Check the Water Level

Another reason for boiler lock out is that the water level in the boiler is too low for it to operate safely. Examine your safety valve and check it to make sure that the water is at the correct height for the needs of your hot water system. You may find that performing a boiler blowdown, and then allowing feedwater to run into the tank, is the solution to your problems. If there is a lot of sediment in your tank, you should consider adding a chemical to the water, which will help to reduce this. Scale and corrosion can also affect water levels.

Check the Pilot Light

Another reason for boiler lock out is that the pilot light is not coming on. The flame may not light if the boiler has become dirty, blocking the gas flue, or it may have failed to spark. Check your boiler light, but be careful about trying to relight the flame if you have been running the gas for a while. Use a table fan and open nearby windows before restarting the pilot light. If the pilot light cannot be relit, this suggests that there is a bigger problem with the boiler, and you should call your energy supply company in order to have the problem fixed.