Hi Sharon
The frost thermostat (if there is one) will be mounted on the wall somewhere.....we usually keep these turned low at about 5 degrees, and they do overrule all of the other thermostats, including the main house one that is usually found in the hall. However, your boiler will have control thermostats internally too, and if they have got the huff then they will have a mind of their own. A boiler thermostat is recognised by its thin copper tube connection (looks like a 2mm thick piece of copper wire). One type has a copper bulb on the end and is usually inserted into the top of the boiler casing somewhere, the other type looks like an aluminium disc about 25mm diameter by 10mm thick and usually lives in the control panel area somewhere. Either could have packed in, to give the problems you mention. Hope I haven't confused things even more!!
John
May 2009
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