Re: Frost control/Drain Valve

by Guest Mon 12 Apr 2021 - 9:54

TBH, im not a great fan of leaving heating or water on as a way of 'keeping the van warm'...
we arent (normally) at home for long periods in the winter cold, but this winter ive not once thought about it...to me its just a waste of money, others think differently.
with the water dumped, if the forecast is a bit dodgy, why not leave it empty and forget about using the Combi.
Combis have a finite lifetime and leaving it on 24x7 just to prevent the water from dumping isnt a great idea.
if you must heat the van (when you're not in it....) use a cheap fan heater on a timer and not your expensive Combi.

by jennyandpeter Mon 12 Apr 2021 - 10:13

I cannot recommend a fan heater unattended at any time , if heat is necessary us a oil filled radiator. Better still leave empty if there is any chance of frost.

by Guest Mon 12 Apr 2021 - 10:50

sorry, i didnt mean fan heater...I meant a stand alone heater...as you say an oil filled is safest....

by steamdrivenandy Mon 12 Apr 2021 - 11:32

A couple of Christmasses back we had a houseful for the season. Our son and his fiancé were given the Eriba Troll out on the drive to sleep in. They kept it warm and snug in there. However our electricity usage, which averaged 400 to 500 units per December, increased to 772 that year and I could think of no other additional usage that might account for it. Recent Decembers have averaged 300 units. Checking the figures, on our current electricity pricing those extra 300 or so units over two to three days cost as around an extra £50.

by Caraman Mon 12 Apr 2021 - 11:52

nuevoboy wrote:During these last, cold winter months I've kept my 'van plugged in to EHU and set the temperature to its minimum 5 degrees heating setting, so as not to drain the water system and all has been fine (except for the 'leccy bill).
I've not had it plugged in since giving the 'van a run last week and we've had a few overnight frosts but the valve hasn't tripped.

Saturday night was cold, but no frosts and I checked the 'van at 7 o'clock when I got up and all still OK.
Went out a 9 and the valve had emptied the boiler, so the temperature must have been still dropping enough to go below 3 degrees inside the 'van.

Rather than leave the heating on overnight, is there a problem with just leaving the hot water system switched on (even on economy) to stop the boiler emptying?

You have a choice of wasting electricity to prevent the water in your system from freezing or wasting 10 litres of water by draining the system and then benefitting from fresh on your next trip. I know which I prefer. The Truma frost valve protects the Combi from damage caused by freezing but it doesn't protect the taps and the pipes leading to the taps. For that you have to drain the system and leave the taps open. Leaving the hot water on rather than the heating may be enough to stop the frost valve from tripping but it might not stop the taps and pipes being damaged.

by Guest Mon 12 Apr 2021 - 12:13

our stops at home, with the van on the drive, generally arent long enough to even bother dumping the water...unless there is a real risk of sustained low temperatures....we get much fresh water flushing through the system with our high usage.
as above, we are 'usually' somewhere between early Jan and late April where water doesn't freeze, so not that much of an issue.