Question

I have a 2005 Hymer Freetec 582. Every time the temperature drops below 4'C the boiler drain valve operates and drains the boiler - as it should. Unfortunately it also completely empties the fresh water tank, which according to the hand book "all other parts of the drinking water system remain filled". For a winterised motorhome that we intend to take with us for winter skiing it is obviously a problem if each day we leave the motorhome to ski we are going to return to a completely empty freah water tank. Can you please assist with advice that may correct the problem?

Answer

The water heater will not drain if the heater is turned on, my advise is to leave the heater on, it will then retain the water. If it is draining the water tank then you will need to do a bit of re-plumbing as it should not do this, I would suggest when the water heater was installed they fitted the drain too low or the water tank too high. Without seeing the installation I am unable to suggest a remedy for this