A boiler that isn’t producing heat is obviously a big problem, and should be dealt with immediately. There are a few different reasons that your boiler could be skimping on heat production. Some of them are fairly easy to fix, some not so much. Let’s go through each of the possible causes for your boiler failing to produce heat, organized by symptom.
Boiler Isn’t On
If your boiler isn’t turning on at all, no matter how high you set your thermostat, there are two main things you should check. First, have a look at your thermostat and make sure that everything is set correctly. Often, when the heater won’t turn on it’s a sign that the thermostat is either not set correctly or malfunctioning. If the thermostat appears to be operating correctly, check the pilot light under your boiler. If the pilot light is out, that’s probably the cause of your trouble. If you don’t have a standing pilot light, you’ll need to call a professional to further investigate the problem.
Boiler is On, But Not Heating
This is a more distressing problem, as it indicates an issue within the boiler itself. The first thing that a professional will often check in this instance is the hot water circulator. It is quite possible that your boiler is, in fact, producing hot water that simply isn’t being circulated throughout the house. We do not recommend that you check the circulator yourself, as it will be extremely hot.
It is also possible that you have a bad valve somewhere in the system, which is preventing the water from getting to where it needs to go. If you have terminal heaters, like baseboard heaters or iron radiators, they should be checked. A good way to isolate the cause of the problem is to check and see if all of these terminal heaters are cold or just one or two of them. If there is just one or two heaters that are malfunctioning, then it is possible that an air bubble in the system is preventing the water from circulating properly.