Truma burning out heating elements in hot water system

[chuckb]

Can someone PLEASE help me.
I bought a new Truma hot water heater to replace the 12 year old one that died. We were in Brisbane a year ago when this happened. We came to Nanango about 1 month after it was installed and set up. That was approx 9 months ago. Since we have been in Nanango we have had the unit replaced and have fried 4 heating elements. The 5th heating element is being shipped today. The unit we bought is gas/electric. We have had hot water for less than a month since we bought the new unit because the gas AND electric don't work. I was told the regulator needed to be replaced so i bought a new one and it still didn't work. They said there might be a block in the line and I paid $150 to have a gas fitter adjust the regulator, check all lines and reset everything. It worked for 1 1/2 hrs and hasn't worked since. As far as the electric part, I even bought a new 15A cord and plugged it into the hot water system by itself to the power box and it still fried the heating element. The elements only last 2 days and gone. This unit cost around $1500 all up to buy, have installed and a compliance plate done. Since all this has started I have had to pay out another $525 for things not covered by warranty. Being on a pension isn't making it any easier. And I also care for a disabled wife which is making everything even harder. ANY advise would be greatly appreciated. This is making me sick at this stage . Thank you

 

[ProfJohnL]

Hello Chuck,
I'm sorry to read of your catalogue of failures with the Truma heater. Truma products are normally pretty good, so I am surprised at so many issues with your replacement unit.

Not specifically Truma related, but I used to be a gas and electrical engineer on caravanning products, and when I was asked to look at cases where continual problems arose, I have to say it was usually down to something wrong with the way it had been installed or used. So have you had the installation checked out by a Truma authorised fitter?

Just for clarity, can you please confirm the exact model of heater you have, and becasue local regulations are different in other countries can yo tell us where you are in the world.

 

[chuckb]

Hello Chuck,
I'm sorry to read of your catalogue of failures with the Truma heater. Truma products are normally pretty good, so I am surprised at so many issues with your replacement unit.

Not specifically Truma related, but I used to be a gas and electrical engineer on caravanning products, and when I was asked to look at cases where continual problems arose, I have to say it was usually down to something wrong with the way it had been installed or used. So have you had the installation checked out by a Truma authorised fitter?

Just for clarity, can you please confirm the exact model of heater you have, and becasue local regulations are different in other countries can yo tell us where you are in the world.

Thank you for getting back to me mate.

Truma UltraRapid B14 Gas/Electric Hot Water System with Cream Cowl & Cover​

This unit has been professionally installed by 2 different companies to Truma's satisfaction. This is their latest and "best" model. I live in Queensland Australia.

 

[Martin_E]

Generally there is only a couple of reasons.
Being used without any water in the heater, this normally invokes the thermal cutout, to reset disconnect from the mains, fill water heater and plug back in, this resets the heater, but continually doing it can kill the element.
I saw one where an element had been fitted on a Saturday afternoon, within 24 hours the element had failed. The cause was found….the owner had used Milton’s in the water at a very high concentration, this basically eat the element! The element went from a shiny colour to virtually black in that time.
I guess generator use could spike them to🤔

 

[chuckb]

Generally there is only a couple of reasons.
Being used without any water in the heater, this normally invokes the thermal cutout, to reset disconnect from the mains, fill water heater and plug back in, this resets the heater, but continually doing it can kill the element.
I saw one where an element had been fitted on a Saturday afternoon, within 24 hours the element had failed. The cause was found….the owner had used Milton’s in the water at a very high concentration, this basically eat the element! The element went from a shiny colour to virtually black in that time.
I guess generator use could spike them to🤔

The water heater has never been run without filling first. First thing I did was go out and buy a new water filter and I don't use any additives in the water. I only used the generator twice since we have been here but can't blame that because it was in between having a new heating element installed both times and wasn't working anyway. I am beginning to think I am destined for cold showers but in saying that, I have been having them for 8 out of the last 9 months anyways. Getting used to them.

 

[ProfJohnL]

I agree with Martin, Failing to fill can be an accelerator to failure. But Chuck has discounted that possibility.

I wonder if there is a failure in the thermostatic control of the elements, causing them to run hotter than they should? I do note they are 1.4kW elements where as the more common size was only 1.2kW

Another thing that puzzles me is how quickly the new elements are failing. The speed suggests whatever is causing it is quite aggressive. The build up of lime scale would I suspect take longer, but I cant rule out electrolytic corrosion, which can eat away at metal quite quickly under the right conditions.

Could it be a batch of elements which are all inherently faulty?

Has the power wiring to the elements been checked for correct polarity and earthing (safety conductor), In the UK you must not rely on the metal work of appliances or caravans to be an effective power conductor in the event of a fault, perhaps something else is relying on the water heater as a route to ground - I have seen this type of fault on some caravans where appliances have not been installed correctly.

I fear we are not being especially helpful on this problem

 

[Martin_E]

I guess another question could be how stable is the incoming power?
These https://www.amazon.co.uk/Reenwee-Re...0&psc=1&mcid=07d29514a05237f592a763da51737415 are good for monitoring power (cheaper might be available)

 

[Dustydog]

The OP unit has an extra element to boost the heating. Is it possible one of the elements is causing the other to fail? One for the Prof or Martin?

 

[Buckman]

I came across this and they are not my words, but may help;

Heating elements are not that delicate. You have an issue that is causing the element to fail. Over current, power spikes play a part in element failure. I would start by checking the water level in the boiler and make sure it is proper- including your boiler fill circuit. If it is not correct it can expose the element to low water levels and overheat. Then you are going to have to move on to voltage and current monitoring of the element and or electronics controlling the element. Also are you buying OEM elements or some other brand ?

 

[Martin_E]

The OP unit has an extra element to boost the heating. Is it possible one of the elements is causing the other to fail? One for the Prof or Martin?

Some food for thought, if the element was replaced and fitted upside down (but I can’t remember if it’s possible) then the element would sit high in the boiler rather than lowdown 🤔 this would mean if for some reason the water level dropped below the element it would trip, it’s just a thought!

 

[Martin_E]

The OP unit has an extra element to boost the heating. Is it possible one of the elements is causing the other to fail? One for the Prof or Martin?

The Rapid is (1300w I think,) one element with temp sensor attached, I guess another thought I just had is if the terminal paste wasn’t applied to the replacement element sensor this may cause an issue 🤔