Truma water heater not working

We're hopefully taking our first trip this year on Monday in our 2015 Symbol with Truma combi. As no shower facilities are open and we have to use ours  (for the first time!), I thought I'd better try it out today.

The handbook doesn't help at all but it seems to suggest turning the leftmost rotary control to position B or C for electrical operation of low or high power. That's it - when I do that and turn the hot tap on, I get only cold water, even after 10 mins waiting for things to heat up.

I thought I'd try it on gas as a second option by turning the same dial to its last position (F). Still no hot water.

I thought I'd repeat all this with the rightmost dial turned to 60 degrees (position L). This made no difference either.

I put the space heater on next (gas) to prove that the combi was actually working and it was fine so basically, I have heating but no hot water. I looked at the main control unit in the floor cupboard to check that the water heater switch was on and it was. 

Does anybody have any ideas - I'm not sure we'd enjoy a showerless holiday.

John.

My thoughts are that as the water is heated in a jacket surrounding the space heater, then if the space heater is running (and the jacket is filled with water) then the water will be heated.

Better responses will be along soon


Gas is 6Kw but elec is only 0.9Kw or 1.8Kw (based on my van with the Combi 6). So gas will heat quickest in an emergency
10 minutes may not be enough on EL 1 (low), give it an hour

did you bleed the air before switching on
are you getting hot water from the sink tap

I did the usual thing of turning the kitchen tap on to clear any air in the system until water was flowing. I've tried both the kitchen tap and bathroom sink tap but no hot water.

From experience you need to wait 40 minutes and use gas for best results or electric as high as you can.  Try the shortest rout to test but don't run too much.  Water is very cold this of year

On the right hand dial, a light should show (amber I think) at about 9 o'clock position until water is up to temp, then it extinguishes until you draw some off and the temp drops again and it lights up again. Do you have this light?

Hi Paul, that's the kind of info that the handbook should be giving - clear and concise.
Yes, I thought from previous answers that I was being impatient in expecting some sign of warmth after 10 mins so I've switched it to the higher electric setting, which has displayed the amber light you suggested. I'll check it in a few more minutes to see if that light has gone off as suggested and to feel the water temp. If it seems ok then, I'll try the shower!.

Success - after leaving the dial on the high electric setting for about 45 mins, the water is hot and, as Paul said, the amber light on the righthand dial has gone off. The lefthand dial also has an amber light but this remains on when the temp. is reached. I'll try the shower out later but have the confidence now that our trip can go ahead. Thanks to all who replied.
John

Caravan/motorhome boilers aren't instantaneous design like you get for domestic use. Units like the Combi rely on heating a store of water, rather than a stream. You'll find that if you draw of too much at any one time the water will chill as cold is drawn in to replace the hot you've used. Fastest heat up is obtained by running the unit on the highest electrical setting and gas together.

the amber light on the left dial is to show electric hook up is being used and remains on while plugged in.

Don't know if anyone has thought of cleaning/ flushing their Truma water heater system out yet ?.
I've been checking out the heater system on gas and electric and all seems fine.
Filled up the water fresh water tank and purged the system, heated up on gas and electric just fine.
Refilled with fresh water,  added Elsan FRESH water tank cleaner and waited 24 hours, turned on the hot tap in the sink and filled a plastic basin with water.
About a teaspoons worth fine lime grit layed in the bottom of the basin.
Flushed out the fresh water system again and all clear.
All ready for fish suppers in Whitby.
Boaby