Hot water heater tripping circuit breaker

[mcanderson]

I have a Quick 20L hot water heater and it is tripping the circuit breaker. So my thoughts are:

1. Thermostat
2. heating element
3. Circuit breaker.

Anyone want to throw in their 2p/c and ideas of checking each in turn.

 

[Keith-i]

Corrosion or loose connection on heater element.

 

[mcanderson]

They are spotless.

 

[James jameson]

Isolate first.
then disconnect the element and test on low ohms with a multi meter between the earth and either live or neutral terminals.
you should get open circuit.
but if you get a reading the chances are the element has gone to earth and needs replacement

i would expect element to be faulty.
breaker is very unlikely
stat also unlikely usually fail open so the heater doesn’t operate
stats must also have a settable part for the temp adjustment usually 55c AND an internal magnetic manually resettable part that cuts the heater if the stat fails

 

[jrudge]

It’s the element

 

[Seastoke]

They are spotless.

If you have a multi meter put it on ohms and switch off heater and then put one lead on the element connection and with one on the Earth terminal if you get a circuit , there will be an Earth fault. Then do the same with the element wires disconnected , if still a circuit your element is Kaput.

 

[jordanbasset]

It’s the element

Agree has happened to me three times, it was always the element

 

[CJ13]

You’ve burnt out the element.
Penguin Eng, Hayling Island, will have a suitable replacement. You also need a big box spanner (54mm??), available on eBay.

 

[Seastoke]

If it is the element, try and get an element made of Aqualoy.

 

[Seastoke]

Also if you don't have a multi meter ,just disconnect the wire from the stat to the element wrap in tape , then switch on if it does not trip then it's the element. Don't forget to switch back off.

 

[James jameson]

Also if you don't have a multi meter ,just disconnect the wire from the stat to the element wrap in tape , then switch on if it does not trip then it's the element. Don't forget to switch back off.

Please don’t do this. At least put the wire in a connector block or Wago. Not just tape

 

[mcanderson]

Thanks all for the help. Will try on Monday to get an element here in France, or it will be one for the cabin bag next trip down.

 

[Hurricane]

I agree with jrudge
You can't really test for this problem.
Just change the whole immersion heating element and that problem goes away.
It is probably a corrosion thing that we get on boats but even home domestic immersion heaters don't last.
On the boat, we get through one about every 4 or 5 years.
I don't use any specific marine ones.
I just replace it with a domestic immersion heater and keep spare ones that can swapped quickly.
In fact, I bought a couple more a few weeks ago.
I have even installed extra isolation ball valves so that I don't have to drain the system every time the element is changed.
Ours is a 3Kw heater so I get mine from TLC Direct - here 11 Inch Std 3kW Immersion Heater c/w Stat & Cutout | Backer (09192VC PACK311/15TC)
If yours is a standard UK immersion heater, make sure that you have a proper immersion heater wrench/ box spanner - they make a special one for that job.

When it first happened, I had a spare heater but I couldn't get the correct box spanner in Spain - all the Spanish ones all have a smaller boss.
I think that the UK ones might specific to the UK.
I suspect that France might be the same.

 

[Portofino]

Castorama do them .
Typical example, but various sizes to suit .Chances are the whole thing is knackered .Far easier just the swop the whole thing out and have the benefit of ALL new going Fwds . New is probably more energy efficient FWIW .

https://www.castorama.fr/chauffe-ea...s-black-15l-sous-evier/5414849557956_CAFR.prd

Edit = pull the shore power socket out before fiddling about .

 

[mcanderson]

Thanks for the tip on changing to a standard domestic unit, but having the ability to heat from the engine is needed so I will stick with the marine unit.

 

[Portofino]

Thanks for the tip on changing to a standard domestic unit, but having the ability to heat from the engine is needed so I will stick with the marine unit.

Arh !
Never missed that tbh .But we do have a geny and when anchoring off tend to run it periodically so flick the immersion switch as well .

 

[mcanderson]

Yes, we do the same. However the redundancy is nice and we ran the engine this morning to heat water for a shower.

 

[superheat6k]

I would avoid a domestic immersion. At 3 kW most of your typical 16amp shore supply will be used just to heat a small tank of water.

1 - 1.5 kW heaters are more expensive but in my experience necessary for a boat calorifier.

I would also suggest no boat should be without a multimeter. I have three aboard mine, including one with a DC current clamp.

 

[Hurricane]

I would avoid a domestic immersion. At 3 kW most of your typical 16amp shore supply will be used just to heat a small tank of water.

1 - 1.5 kW heaters are more expensive but in my experience necessary for a boat calorifier.

I would also suggest no boat should be without a multimeter. I have three aboard mine, including one with a DC current clamp.

The original one fitted to our boat was 3Kw - identical to a domestic one.

 

[Hurricane]

Thanks for the tip on changing to a standard domestic unit, but having the ability to heat from the engine is needed so I will stick with the marine unit.

I can't see any technical difference between a domestic heater and a marine one - except the price of course.