| Comment | Most boilers will have an automatic frost detection system that will briefly fire it up once the circuit temperature reaches around 5C irrespective of what you're doing with the thermostat
The water in your central heating should also contain anti-freeze fluid, so that's not going to be an issue unless you let things really drop (i.e. leaving the house empty and not running the heating for weeks)
Usually first thing to go wrong is the boiler condensate pipe (which dumps water from your boiler into your waste pipe) freezing up and stopping the boiler from working. It should be insulated from external walls but often isn't. For this reason it's a good idea just to run your boiler a few minutes a few times a day when outdoor temps are subzero even if you're not using it otherwise. You can tell it's becoming blocked if your boiler starts makes watery gurgling noises and stops running |
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