boiler - should we turn it off?

[melly]

Hi, there I hope someone can help. I live in France and have a holiday cottage -the fuel boiler for the central heating system seems to work ok most of the time but has a tendancy to cut off - especially when we most rely on it - when it's freezing. This winter it will be empty so we were thinking it might be best to turn it off and drain the system since we dont want to buy fuel just to keep the thing ticking over. However, our plumber seemed reluctant to do this and said something about anti-freeze which I didn't quite understand. It occured to me that maybe he was suggesting that if the system has anti-freeze in it (which we had put in last winter) it should be possible to just turn off the boiler and the water supply. Would this be okay or would we still risk frozen pipes etc?

 

[Bernie2]

Hmm!

Hard to say, depends on temperature drop and quality of anti freeze. Also many boilers have an anti frost device which switch's on if the temperature at the boiler drops to near freezing. But it could be expensive on fuel to keep the boiler on if your somewhere cold.

The thing is, switching the boiler off obviously cuts this function out.

But if the systems anti freeze is in good condition and suitable for the low temperature range experienced then the system should be okay switched off. If it isn't of course you risk freeze ups.

Think of it the same way as you would a car's cooling system and try and work from there. In point take a sample to the local garage and they will probably test it for you if they have the equipment.
The thing is it might or might not work, for most car anti freeze is glycol based and if you have a combi boiler it is probably not glycol in the system, glycol is dangerous to humans and if it got into the mains water heating side you could poison people.

Good Fortune!

 

[melly]

Thanks Bernie2. The boiler isnt a combi it must be over 15 years old a massive old Dietrich! There is an anti-frost programme on the house thermostat but because we cant rely on the boiler not to cut out anyway we cant trust it. Besides, as you say, it is expensive to buy fuel to keep going all winter. So looks like draining the system might be the way to go.