Truma ultrastore water heater issues

[tommyatr]

Hi all.
Just joined the site after reading up on various posts regarding the above.

Basically I have an abbey aventura 330 6 berth that i recently purchased.Was away for a few days there and couldn't get hot water working.the green light doesn't come on at all on control panel, found the fuse on pcb board to have blown. Changed fuses but they blow immediately. Checked all out today when I got home and heating element has continuity and an ohms reading of roughly 61.the water heater won't work on gas or electric.

Any ideas before I send pcb away for repair, to me a fuse constantly blowing would indicate a short but can't find anything.main fuse under consumer box is ok.

 

[Raywood]

I know it sounds basic but is it the rights size fuse. Cannot remember what size it is but it is a large one. If not that I am afraid you are probably right.

 

[bertieboy1]

Tommyatr,
Your reading of 61ohms is about right,this gives a current of 3.7 amps on 230 volts which in turn gives 835 watts ( 3.7A*3.7A*61ohms )
Our ultra store rating is 850 Watts @230 volts,this equates to 3.69 amps ( 850W/230V)
I don't know much about the ultra store or it's components but if the fuse ruptures on both gas and electric operation this suggests a common component failure - the PCB?
The difference in your current and mine can be explained by the accuracy of your multimeter and also your reading.accuracy.

 

[Woodentop]

Tommyatr,
Your reading of 61ohms is about right,this gives a current of 3.7 amps on 230 volts which in turn gives 835 watts ( 3.7A*3.7A*61ohms )
Our ultra store rating is 850 Watts @230 volts,this equates to 3.69 amps ( 850W/230V)
I don't know much about the ultra store or it's components but if the fuse ruptures on both gas and electric operation this suggests a common component failure - the PCB?
The difference in your current and mine can be explained by the accuracy of your multimeter and also your reading.accuracy.

Except that (1) we still use a nominal 240V in the UK, and (2) you need to check the actual supply volts presented to the heater to use that calculation.

 

[ProfJohnL]

Tommyatr,
Your reading of 61ohms is about right,this gives a current of 3.7 amps on 230 volts which in turn gives 835 watts ( 3.7A*3.7A*61ohms )
Our ultra store rating is 850 Watts @230 volts,this equates to 3.69 amps ( 850W/230V)
I don't know much about the ultra store or it's components but if the fuse ruptures on both gas and electric operation this suggests a common component failure - the PCB?
The difference in your current and mine can be explained by the accuracy of your multimeter and also your reading.accuracy.

As far as I am aware, the mains element and the 12V systems are electrically isolated, so there is no common fuse to both systems. If neither system is working then that suggests two faults or possibly attempted incorrect operation by the user.

I suggest you obtain a copy of the operating instructions and check how you are trying to use the appliance

try these
https://dealernew.truma.com/_anweisungen/Truma_Katalog/pdf_verzeichnis/70_000/70020_33900.pdf

As for the heating element resistance BErtieboy has shown the calculations, but what he hasn't accounted for is the change in resistance of teh element when its hot. Suffice to say a cold resistance of 61Ohms is perfectly normal and not out of range.,

 

[WoodlandsCamper]

Except that (1) we still use a nominal 240V in the UK,

No we don't, it's been 230v for a long time. EU and all that, the UK Government agreed to harmonization at 230V on 9th March 1993.

 

[Hutch]

Just checked the mains voltage her in RMK, and it's fluctuating between 238 and 241volts. I thought it was supposed to be 230, volts, I will check again at in an hour when most people are cooking, It might change,
At least it's stable.

Edit, yes I know my multi meter is not calibrated, before the Prof gets me. But just checked with my 2nd MM and that reads the same.

 

[Damian]

Mains voltage is always fluctuating between 220 and 250v depending on demand.

Effective date -- Nominal voltage----Permitted tolerance-----Permitted voltage range.

Pre-1995 ---------240 V -------------- +6 % / -6 %--------------- 225.6 - 254.4 V
1 January 1995--230 V-------------- +10 % / -6 %---------------216.2 - 253.0 V
April 2010 (proposed)--230 V------ +10 % / -10 %------------- 207.0 - 253.0 V

 

[Hutch]

Better than Nigeria, It used to fluctuate between Nil and 300 volts. Everyone had voltage stabalisers on equipment.

 

[Dustydog]

I don't know the answer yet.Why isn't it working on gas? Nothing to do with mains voltage!
12v provides the spark for ignition.
Is it coincidence there are two problems?
I'll sleep on it but I bet our Prof comes up with a solution.

 

[ProfJohnL]

I don't know the answer yet.Why isn't it working on gas? Nothing to do with mains voltage!
12v provides the spark for ignition.
Is it coincidence there are two problems?
I'll sleep on it but I bet our Prof comes up with a solution.

As ever with threads like this we get so far, and then it becomes clear the questioner is not familiar with the detail workings of the appliance, and I become concerned the information and suggestions may actualy lead the OP to do something they shouldn't.

We don't have access to appliance and its installation, so all we can do is speculate. and currently (excuse the pun) we don't know if the OP is doing something wrong, or if the equipment is actually faulty or not. though as the owner reports a repeatedly blowing fuse which is not normal.

In this case I am sure the best solution first for the owner to get the caravan properly looked at by a techie who is familiar with gas and the Truma product.and its repairs.

 

[tommyatr]

I have a feeling there has been an underlying issue for a while.

Found a receipt for a new element from 2014, when I took out the one that's in just now it looks new, still all shiny as if it has never heated up and started to discolour.

I'm just trying to find out if anyone has had similar fault as not prepared to pay silly money on getting a 10+ year old caravan water heater looked at by local dealers and paying thru the nose for new parts when there are people who will repair them for alot less.

I do appreciate all replys and do not wish to sound ungrateful for any help received.

I just find it odd that the light isn't working on the dial if the pcb is only for the gas burner control.

At the moment I'm looking at sending the pcb away for testing and repair as can't see much else that can cause this without pulling the whole unit out, if pcb comes back ok then I suppose that's next before biting the bullet and taking to dealers.

Many thanks once again

Tommy.

 

[Martin_E]

It could be that the tank has got frosted, expanded and now sits on the burner causing a short. But that wouldn't (as far as I am aware) effect the 230v side

 

[ProfJohnL]

It could be that the tank has got frosted, expanded and now sits on the burner causing a short. But that wouldn't (as far as I am aware) effect the 230v side

I'm sorry Martin,
I know the Truma product quite well, and what you suggest I have never seen, and consider it to be highly unlikely. The shape of the tank is quite strong along the sides and bottom, if it were to suffer frost damage form expansion as ice is formed, it deforms the top and some times blows the tank to tank top joint.. Also there is no component in the burner that carries the 12V supply, so again there is no conceivable way that wold be enough to blow fuses.

The information I have seen so far would in my opinion require the unit to be fully inspected and bench tested.

As removal of the appliance requires breaking gas connections this should only be done by a competent fitter.

 

[Martin_E]

John

I suggest you do some more research, the top and the bottom of the tank can react the same with frost damage, have you been to the Truma training room? They have a good example of a blown tank up there.

So you are saying there is no voltage/amperage at the spark igniter, I will press the start button while you stick your finger near the ignitor when it's sparking!!

 

[ProfJohnL]

John

I suggest you do some more research, the top and the bottom of the tank can react the same with frost damage, have you been to the Truma training room? They have a good example of a blown tank up there.

So you are saying there is no voltage/amperage at the spark igniter, I will press the start button while you stick your finger near the ignitor when it's sparking!!

Yes Martin I have been trained on Truma along with other manufacturers products (many years ago) and I have probably handled more of them than most on the forum. I have never seen a significantlt distorted truma tank bottom through frost damage here in the UK.

The damage that can be created by frost can be quite alarming, but the samples often shown of worst case damage are often artificially created by putting a heaeter in a deep freeze, to prove a point. The Truma tanks were always less susecptable to forst damage compared for example to the Carver Cascade 2.

I didn't say there was no electrical connections in the burner only that there is no direct 12V supply . The current dispated through the spark ignitor is in micro amps but at about 12kV, if the spark electrode is shorted to other metal parts it does not cause the fuses to blow as the impeadence of the HT system is high.