I have a SIME friendly Format 80E boiler fitted in my static caravan. The CH system water was tested recently and had zero % anti-freeze in it. Does anyone know what the correct %age should be? I put aprox 25% car radiator anti-freeze in and after a few days the seal went on the pump and filled the motor up with water. I can only assume the fault is due to the anti-freeze. Is there a special anti-freeze for CH systems?

Charlie, January 2009

standard antifreeze that you put in a ar for example is not the correct antifreeze to use at all. it will do more damage than good. you need to buy someting called 'sentinel' central heating antifreeze and the amount you will need to put into the system will be given on the antifreeze container

APR Plumbing, LANCS, January 2009