DIY Doctor UK DIY Forums

We have a combi boiler.

Over the last few weeks, the heating hasn't been set to come on. But at occasional random times, the radiators feel warm as if the heating has been on. But it hasn't been set to.

We've never been able to catch it when it is actually on and the boiler is fired up.

What could this be?

is your boiler vaillant as these do have a 'warmstart' which fires to boiler to keep instant h/w,if so when it fires to top up the h/w the divereter valve could be letting by,there are othe makes that have this too let me know which yours is