Boiler temp in vacant house

BongoW

Any suggestions on what temperature a Combi boiler should be set at if the house is vacant for an extended period? I’ve googled that the house temp should be kept at at least 13c, but there’s no room thermostat and so am just having to set the boiler temp. I’m doing trial and error at the mo, but would prefer to know the most efficient temperature to set the boiler temp at to avoid both freezing pipes and unnecessary bills. I’ve currently set the boiler on low and constant, although I’ve read conflicting opinions on this.

tacpot12

To some extent the answer will depend on how much moisture gets into the house on a normal basis and the outside temperatures. You want to keep the house heated enough so that any moisture that does get in is held as water vapour for long enough for the ventilation in the house to allow it to leave before it condenses on cold walls and windows. Trial and error is the best way to do this unfortunately.

But you should also check that the temperature control on the boiler is doing what you think it is doing. Some boilers have a thermostat that controls the temperature of the central heating water IF the boiler is on. The thermostat doesn't turn the boiler on if the temperature in the house drops to a certain point. In my experience it is quite unusual to have the boiler actually turned on and off by a thermostat that is mount on the boiler. Also some combi boilers have a thermostatic control for the temperature of the hot water that comes out of the taps.

BongoW

Thanks so much for your reply. I’ve just bought the house and so am having to get my head around this new boiler. It’s quite an old house and already has some mould/damp problems (which were conveniently hidden by very large furniture whilst it was on the market). I’m going to have to get someone in to sort out what that’s all about, but thankfully the vast majority of the walls (and all windows) are warmish and dry. There’s just damp in certain areas, some is pretty bad. I turned the boiler temp down when I got the keys and I can see the boiler does go off and then kick back in when the temperature drops below the set temp. The house isn’t freezing cold whenever I go back in, but I also turned the radiators down today, as they were warmer than needed. I guess I may have to just fiddle about with it for a bit. I’ve got someone coming in tomorrow to look at the damp, so I’ll pick their brains too. Thanks again!

macman

Most modern boilers have a frost stat, which should kick in if the temp goes below about 6C.