Truma Water Heating Element failure

[ricaroo]

Hello all, following winter my 850w Truma Ultrastore water heating element (2008 Elddis Autoquest 100) has failed for the second time so I find myself contemplating another replacment. On inspection apart from some brown sludge at the top, the element looks fine but I would suspect moisture ingress around the solder.

Basically these items are nothing but a big electric kettle element but at least 10x as expensive so I am most reluctant to purchase another as they do not seem very robust.

 

1)Does anyone have any tips/ideas?

2) Are there any alternative elements on the market?

 

PS The system is drained in winter via the water dump switch under the bench.

[lennyhb]

Why bother cheaper to run on gas anyway, if they fail that often is it really worth the cost & hassle.

[ricaroo]

Thanks for reply Lenny I am actually thinking along the same lines but was hoping for a more acceptable conclusion.

[Dave Newell]

One of the most common causes of premature element failure is the switch being left in the on position so that when the hookup is connected the heater comes on straight away, if the boiler is empty of water the element will not last very long.

 

D.

[Derek Uzzell]

Ricaroo

 

Realistically, there is little you can do to improve the reliability of a Truma Ultrastore boiler's 230V heating capability other than ensure that the boiler is always full of water when operating the boiler. The heating element has an excess-temperature cut-out, but I've seen it suggested that, despite this protective feature, operating the boiler empty (or only partially full) on 230V can potentially harm the element.

 

In Posting 205019 in this 2008 "Practical Caravan" thread

 

http://www.practicalcaravan.com/forum/general/27416-truma-ultrastore-problems

 

Full Timer says "...I have recently removed 2 for customers and on each there was a weld that was cracked and possibly leaking water into the element, so it could also be a manufacturing fault" - this tallies with your suspicion that water has entered the element itself.

 

As the Ultrastore boiler is pretty much the norm for water heating for caravans, and the 230V option will, often as not, be fitted to the boiler in such cases, many thousands of Ultrastore boilers with a 230V capability will have been made (and been operated) since the appliance was first marketed in 1983. I've no idea what the heating-element failure-rate has been since then but, although there are plenty of on-line discussions about element-related problems, I suspect you've just been unlucky to have had two failures in 6 years.

 

I'm confident that the 230V element used in an Ultrastore boiler (I assume your element is the 850W version) is unique to that appliance and that no alternative element is available. The asking-price of a new element is (as you'll be aware) about £70.

 

I believe that Truma's warranty period is normally 24 months. If the 2nd element was relatively new when it failed, it might be worth you contacting Truma(UK) to see if they would provide an under-warranty replacement.

 

 

 

[ricaroo]

Thanks Dave, the switch was never left on but I think despite draining off via dump tap the boiler still does hold remaining water so this is a strong possibility.

The only other thing I can think of is that following winter I sterilised the full system with dilute Milton fluid which I left in for 3/4 days. When I removed the element there was some brown sludge around the top of the element but perhaps this is normal?

[ricaroo]

Hello Derek and thanks for taking the time to reply.

 

I cannot see any cracks on the element but the water within the boiler turned grey/black indicating it had popped following water ingress into the element.

 

I have thought about warranty and poor manufacture is a realistic factor but I do not have a receipt and cannot see any identifying serial numbers on the element. However, it's probably worth a shot.

 

[Dave Newell]

ricaroo - 2014-05-11 8:55 AM

 

Thanks Dave, the switch was never left on but I think despite draining off via dump tap the boiler still does hold remaining water so this is a strong possibility.

The only other thing I can think of is that following winter I sterilised the full system with dilute Milton fluid which I left in for 3/4 days. When I removed the element there was some brown sludge around the top of the element but perhaps this is normal?

 

Hi Ricaroo, I'm sorry but you're first sentence in this reply just confuses me. If the boiler retained water to above the level of the element then there would be no problem other than frost damage which is not what I was suggesting, I am therefore at a loss as to what "....is a strong possibility" .

 

Milton is not advised for sterilising motorhome water systems as it is a chlorine based steriliser which can damage stainless steel equipment. Yes plenty will say they've used it for years with no problems but it is still not advised by the manufactruers and could therefore be a possible factor in your element failures, especially as it was left in the system for 3 to 4 days.

 

D.

[ricaroo]

Hi Dave

 

Prior to removing my broken element I drained the water using the dump tap just as I do when preparing for winter but when I detatched the in/out water pipes from the tank a few pints of water had remained in the system. This got me thinking that frost damage could be a possibility.

 

Didn't realise that MILTON could affect the element but your point might hopefully prevent other Motorhomers reading this suffering from a similar experience.

 

Thanks for your response!

[Derek Uzzell]

ricaroo - 2014-05-12 9:13 PM

 

Hi Dave

 

Prior to removing my broken element I drained the water using the dump tap just as I do when preparing for winter but when I detatched the in/out water pipes from the tank a few pints of water had remained in the system. This got me thinking that frost damage could be a possibility.

 

Didn't realise that MILTON could affect the element but your point might hopefully prevent other Motorhomers reading this suffering from a similar experience.

 

Thanks for your response!

 

If you haven't got Installation/Operating Instructions documentation for your boiler, you can download it from here

 

http://dealer.truma.com/_anweisungen/Truma-Katalog/gb/boiler/boiler_ues.html

 

I'm not 100% certain which model of boiler you have, but this leaflet mentions maintenance on Page 5

 

http://dealer.truma.com/_anweisungen/Truma-Katalog/pdf_verzeichnis/70_000/70020_85200.pdf

 

"Use wine vinegar for de-scaling the water heater, this being introduced into the appliance via the water supply. Allow the product to react and then thoroughly flush out the appliance with plenty of fresh water. To sterilise the water we recommend Certisil Combina or Micropur Forte."

 

Earlier Truma boiler Operating Instruction leaflets add the warning "Other products, particularly those containing chlorine are unsuitable."

 

As Dave advises, Milton is not advised for cleaning/sterilising leisure-vehicle water systems. Milton contains sodium hypochlorite that (in a strong concentration) may bleach and damage fabrics and corrode or damage metal including stainless steel. Whether your use of a (presumably) well-diluted Milton solution left in the boiler for 3 to 4 days damaged your heating-element is anybody's guess, but Milton's best avoided

 

Truma's schematic of a boiler indicates that water entering the boiler is delivered by a pipe to a point close to the bottom of the water 'tank'. When draining the boiler, as long as siphoning of the water-tank through the drain-valve occurs, almost all the water-contents should drain out. Assuming that Truma's drawing is accurate, if siphoning stops before the boiler is empty, the lower part of the 230V element will remain immersed in water. That several pints of water came out of your boiler when you removed the inlet connector suggests that draining was incomplete and all of the element may have remained under water. So your frost-damage suspicion may be correct.

[ricaroo]

Elementary Derek (No pun intended of course) and thanks for the tips and all the useful info.

When i eventually replace the element i'm going to ensure it is switched off when empty, check it is completelly drained for winter and use the correct cleaning solution. Now that seems good for starters doesn't it?

 

Thanks Again

[Derek Uzzell]

Truma does comment on draining down the boiler, saying (in the Operating Instructions) "...Check that the water contents have been completely drained (10 or 14 litres)".

 

Your boiler is likely to be the B10 (10 litres capacity) version, but - other than putting a container beneath the drain hose - I'm not sure how one is expected to know that the boiler has fully drained.

 

In your case, as your boiler still had a good deal of water remaining within it despite having been drained down, I'd be tempted to experiment with draining it and measuring how much water comes out. If, say, only 7 litres comes out, you will need to adopt a different draining procedure.

[ricaroo]

Derek

 

I am quite sure residual water remained despite draining down via dump tap so I will follow your advice in future.

 

Thanks again

 

 

[carloszappa]

Hi All!

 

sorry to proceed this way, but i have no more ideas... i need to connect a fan to my boiler and i don´t have the pcb schematic´s, so i don´t know wich pins to connect, even if it must be solder in the pcb (B096), i´ll

have no problem with that,i´m just asking if you know where to get the document (pcb schematics) or give me some other idea.

Many thanks and sorry once more

 

by the way boiler TRUMA B10, i supose.

thanks

 

Carlos

[Dave Newell]

Why on earth do you "need" to fit a fan to a water heater?

 

D.

[Derek Uzzell]

Carlos

 

Welcome to the Out&AboutLive forums.

 

You could try this company

 

http://www.arelectronics.co.uk/contents/en-uk/d28_Truma_Ultrastore_PCB_70020-72100_Repair.html

 

If they can repair a B10/Ultrastore's PCB, they should have technical information about the PCB itself.

 

(It would be interesting to know why you wish to connect a fan to your B10 boiler. As Dave Newell says, it does seem - on the face of it - an odd thing to do, but I'm sure you have a good reason.)

[drpeej]

I have burned out one element by draining water with power connected and when I thought I had done it again (fortunately the cutout worked and reset on this second occasion) I thought I should do something about it.

 

What I have done is to add a latching relay to the element power supply.

 

I used a small 12v latching relay circuit board that I purchased off eBay. This drives a double pole mains relay in the element power lead.

 

The latching relay is set using an illuminated momentary press switch which I have fitted next to the Truma gas control. This switches on and illuminates when pressed once and switches off when pressed a second time.

 

When connected to mains power, the heater element is not powered unless the button is pressed to latch the relay. If the 12v power is switched off in the motorhome, the relay resets to the off position automatically and needs another button press to switch it on.

 

I have also added a neon indicator to the element side of the relay so I can see when power is actually applied.

 

If anyone wants more detailed construction details I can post them here. It wasn't a difficult project. Most of the work was in sourcing appropriate components (mainly from Maplin). Access was a bit awkward. Everything is safely protected in two plastic boxes (one for the low voltage latching board and the other for the mains relay)