Truma water heater probs

[Gemani2]

Hi all, help needed
we bought an old camper about 2 weeks ago and when we bought it the water heater worked for about 10 mins then red light came on.

went away last week all excited and forgot about the water heater probs..until we switched it on and thought oh..should have sorted that before we came away but in all the excitement of the van had a million other things to do!

So..we switch it on, get green light, you can hear the ticking/clicking in quick succession , of the ignitor..., you then can hear a 'boof' sound as if the gas has ignited..after about 9 seconds it has a click and red light comes on...gas is okay, water is okay. when we hear the boof sound we get heat coming out of the vent so gas must be igniting even though just for a short time.

I've looked through other threads but are stumped on this as it worked for about 10mins when we first had the van and it gave us hot water so not sure why it suddenly went awol on us

its a truma water heater.

I really don't know where to look first..any ideas ? someone told us to keep trying in quick succession in case it was air lock in gas ?

I'm not sure of the history of the van before we had it, not sure if laid up for a time or used.

 

[Deleted member 5816]

Truma Water Heater

Hi I would not advise to keep lighting it. If there is air in the gas pipe try running the hob for a few minutes to purge as much as possible,try the Truma after about 5 minutes and if needed wait at least5 minutes between try's. Is there water through the hot tap, you must have the vent off to feel the warm air expelled.

Try a google search for your exact problem you will get loads of results.

Alf

 

[Gemani2]

Have had the fridge and hob running all week whilst away, ran the hot tap in sink and shower to make sure no air in supply , it's baffling us that it did work and now will not?

 

[n brown]

sounds like this-- Truma Thermocouple Truma Thermocouple [M30050-13900+] - £12.08 : caravan accessories,caravan parts,caravan spares,caravan breakers,west midlands, Cheapest Caravan Parts In The West Midlands if your heater has this type

 

[Gemani2]

[No message]

 

[n brown]

Signs and Symptoms of a Bad Hot Water Heater Thermocouple | eHow

 

[lebesset]

just had to solve this for a friend , could be the same problem ; the gas feed pipe was partly blocked by heavy ends at the lowest point just before the heater , although there was enough to light there was soon insufficient gas to keep going and on came the dreaded red light

undid the union nearest to the heater , compressed air through the pipe from the bottle end , out poured the heavy ends [ only a tiny volume ] and no further problem

if you don't have compressed air , just turning the gas back on briefly may produce enough pressure

 

[Robmac]

As Brownie said - sounds like Thermocouple.

 

[Gemani2]

Everyone on this forum is brilliant and slowly we are getting there so thank you to all who have replied.

We can now get hot water , it stays on for about 10 mins but then the red light comes on again. It does not always work again, very hit and miss. We have to have the dial on about 50 temperature for it to come on for 10 mins, but why the red light...it's driving me nuts !

I do have a compressor, so will,try it tomorrow

Thank you again all, really do appreciate your help

 

[n brown]

if it stays on for more than a few seconds after releasing the knob then it's not the thermocouple

 

[Gemani2]

Think we have sussed it, we found a tenny little red switch on the kitchen worktop behind the hob( in between hob and window) had no idea wot it was for, we switched it and now the boiler is working . We have no idea if this switch is linked to the problems or if its just coincidence that we have switched it and its now working...but we will leave the switch as it is. We now have hot water and all working...BUT it only works the next time we switch it on if we make sure we switch the temp dial to 'O' before switching boiler off.

Thanks to all that helped ..if there are any other 1989 hymer 644 owners who also have is little red switch I will interested to hear if its connected to the boiler !

 

[Gemani2]

Pics of my little red switch

 

[MATS]

Problem with our truma boiled down (pun) to a faulty room temperature sensor. Water only all ok. Put heating on and red light came on. If Themesitor (room temp sensor)was disconnected heating came on fine on full. So we replaced thermistor and all has been good since then. Not sure if someone has improvised here and put the switch in to disconnect the room thermistor - just a thought as this could be something else.

 

[Gemani2]

Thanks Mats , ours is hot water only....and i'm not touching the little red switch again, going to leave it well alone ! if it aint broke, which its not now, don't fix it !!

thanks for all your help folks

 

[Gemani2]

O.M.G....this water heater is driving me nuts! It's not working again ! ??? We thought we'd sussed it, see previous notes...but just tried it and same again, back to square one

It's a water heater only, gas is on, water in the tank, same as before....any comments appreciated !

 

[gaz2676]

check outside see if youve left the cover on ....if so pop it of leave for 30 secs try again ...good luck
the cover goes on for traveling protection

 

[Gemani2]

Water heater again...blown out the pipe with compressed air, changed the gas bottle to a new full one, we can't see where the thermo wotsit is to check it and can seem to get to it / find it , we have an exploded view / diagram which is so not clear..can any one point me to the thermo wotsit ?

 

[Smaug]

The thermocouple is a little copper/ brass tube (it may be plated) usually with a crimped end that sits in the pilot light flame. When hot it keeps the gas flowing, if the pilot light goes out, it cools down & cuts the gas off. It has a copper tube that generally goes to the electronic control box somewhere.

A final thought; my water heater vent is under a window which has a micro switch on it, if you open the window you risk getting fumes in the van so the micro-switch turns the heater off.

 

[Gemani2]

Update on probs;

Hubby took this apart ( and flooded the camper) cleaned all the bits he could. Everyday for week he went out and tested it, worked perfectly first time. We went away for the weekend, not working! We have come back and guess what, working again...now we have possibly narrowed it down to low battery voltage ? For some reason our camper is not rigged up to charge the liesure battery, expect on plugging in to ehu, this seems to charge the battery. Every time we have tried it at home we have been plugged in. When away, not on ehu...hubby going to get a split charger thingy to sort out the charging issue, but my question is...could the low voltage in the battery be a cause for the water heater not to work? If it was the thermo wotsit, surely it would not work at all? Everything seems to be pointing to the battery...when we have been on our journey the fridge has been on 12v and, as its not charging, when we get to where we are going battery is down....could it be as simple as the battery?

 

[Smaug]

FWIW I had a similar set up (CI Carrioca 635) where the leisure battery was only charged on EHU. Why they build them like that I cannot understand. I fitted a split charger & it has improved a lot, but many on here recommend the B2B battery charger systems.

12v fridges can use a lot of power & I have found that if I have the fridge on 12v while driving then the leisure battery doesn't charge up that much. If I need the battery to charge while driving AND the fridge on I put it on gas. Sometimes it will blow out, but mostly it works fine on gas while driving. It's never going to gas me as the gas will be cut off if the pilot goes out & there is a re-ignition device initially - it's only if it doesn't re-ignite that the gas supply is cut.