Truma Water Heater problems

[Brackpack37]

Hi chaps Discovered at the weekend that the Truma water heater in my Weinsberg Toskana has stopped working, I had a cursory look last night to see if anything obvious had come adrift but found it impossible to see any of the workings. Basically when switching the heater on at the control panel, which is just a rotary knob, a green light should appear and you usually hear the burner light, none of this now happens. Is there anything obvious that I have forgotten to do or can do to remedy this. I am not in any way a competant electician so thats not feasible. If nothing is obvious I therefore need the assistance of hepl, I live in the Surrey (Effingham)area, can anyone recomend a company that can sort the problem. there aren't any m/home dealers near me that I know of. Thanks for any assistance David

[carolh]

make sure the 12v supply is on, because it needs this for the ignition - hope this helps

[Brackpack37]

Thanks carol, yes 12v is on

[Derek Uzzell]

Your description of operating the control-switch suggests that your motorhome is fitted with a Truma Ultrastore water-boiler, either a B10 (10 litres capacity) model or a B14. When there's a problem with the gas side of these appliances the usual reaction to an abortive attempt to start up the boiler is for the red "Failure" light on the control-switch to illuminate. That absolutely nothing happens when you move the rotary switch to the ON position suggests that the problem may be electrical. Truma's B10/B14 Installation/Operating Instructions offer no trouble-shooting advice on electrical malfunctioning, but definitely the first thing to do is to confirm that 12V power is actually present at the boiler and, if not, to check for failed fuses. Standard practice would be for the cable that provides 12V power to the boiler to be fused, usually just on the positive-feed side but possibly on positive and negative. Where this fuse (or fuses) is/are will be installation-dependent. If you are lucky then the Weinsberg handbook may help: otherwise some detective work will be needed. If the 12V power-supply fusing checks out OK, then I note there is also a 1.6A slow-acting fuse on the boiler's printed circuit board (pcb). The pcb is located beneath a removable triangular cover where the cables to the control-switch and 12V supply connect to the boiler. However, whether you can actually get at the pcb with the boiler in situ will depend on how bloody-minded the Weinsberg designer has been!! Suggest you visit Truma(UK)'s website (www.trumauk.com) for a list of their approved Service Centres. Even though there may be no motorhome dealer near you, a competent caravan dealership should be able to assist.

[Brackpack37]

Hi Derek Thanks for your reply It is a B10. When turning the knob neither of the lights (green/red) light so your observation that its an electical fault sound the most obvious. Unfortunately I have no handbook with the van, so is it possible that the fuse cotrolling this is incorporated into the fusebox in the glove box which I assume is the engines fusebox?. The control panel on the wall has push buttons which I can only assume are a type of cutout switch but as I know NOTHING about electics I can only guess. I will take a picture of the panel and post on here. David

[chas]

hi- I had a similar problem but in my case the leisure battery which had a fair bit of use , without EHU charging was not up to ignite the gas, Truma do mention this in their trouble shooting guide, so make sure its nicely charged, 13.6v at least. might just do the trick. regards chas

[Brackpack37]

Thanks Chas for your assistance, unfortunately the leisure battery is fully charged

[Frank]

Hi Derek has given you some very sound advice there. I have just had some problems with my B10 finding that I had no lights at all when I went to switch on. I located the PCB and found that the 1.6A fuse had blown. I replaced this and the boiler worked as normal. The down side is I tried to use it again last week and this time I had lights but it failed to heat up so I am left wondering if the PCB needs replacing (~ £130.00!). However, in your case you could simply try checking the 1.6A fuse first. Regards Frank

[Brian Kirby]

David

Won't help the immediate problem, I know, but getting a handbook for the Wensberg would be a good idea. 

These are, as you now know if you didn't before, quite complex vehicles and although most of the components are fairly standard and come from a limited number of suppliers, how these are assembled and wired or otherwise connected togther is not standard across makes. 

A manufacturer's handbook is quite a necessary item when things go wrong, or even if you just need to check correct methods of use.  Getting something wrong on the basis of an assumption can prove expensive!

Could a previous owner, or the dealer, help?

Good luck

Brian

[Derek Uzzell]

There's an "Electrical Woes" thread beginning 17 Jan 2005 that might possibly be helpful (Search forum on "Toskana" and "All Posts"). Frankly, unless one is familiar with the particular model of motorhome and the equipment used in it (and I know nothing useful about the Weinsburg Toskana) it's really a waste of time trying to guess where motorhome manufacturers put fuses for 'domestic' kit. Assuming that the problem is electrical, the fault-finding sequence here is straightforward. Generally, is it just the boiler that's playing hard to get? If there are several electrical items not working, then a major fuse has probably failed. If the problem is confined to the boiler, then... 1. If there is no 12V power at the boiler then there's a supply problem 'upstream' - very possibly a blown fuse. 2. If there IS 12V power at the boiler, then the fuse on the pcb may have blown. 3. If the pcb fuse is OK, then the pcb itself (or even the control-switch) may have developed a fault, in which case specialist attention will be needed. I'd certainly be tempted to remove and check any fuse that's within the 'caravan' part of the vehicle and looks like it's an add-on rather than base-vehicle related, just in case you strike lucky. Beyond that, I think that you are going to have to bite the bullet and get someone with electrical skills to look at your 'van.