Water Heater tripping external RCD and fridge doesn’t work on elec

[Mike123]

Just got on site and when plugging in EHU, the external rcd trips immediately.

Tracked it down to the water heater, as isolated the internal trip switches and the water heater left off allowed the other 240 to work.

Also at the same time noticed the fridge doesn’t work in elec - seems to be the same time these faults have occurred.

Apart from testing the ohms re the heating element to confirm if faulty, any thoughts….

Able to use gas for fridge and water heater so have back up in place - thanks in advance

 

[PP Bear]

Had the same and turned out to be the internal heating element had blown a hole in it, my fault completely when I was a newbie and had to change the element.

 

[Mike123]

That’s what I expect - but not sure why the fridge has gone on the blink…..

 

[autorouter]

Are you sure the fridge 240V is not on the same trip switch as the water heater?

 

[Mike123]

Good call - the internal rcd had water heater only on the label.

Are you sure the fridge 240V is not on the same trip switch as the water heater?

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[dunnah01]

How many amps is the EHU supply?

 

[Mike123]

16 amp

 

[Mike123]

So can confirm that both the fridge and water heater come off “MCB 3” regarding 240v.


Question is - how do I find out which one is tripping the external rcd ????

 

[rb62]

Turn the both off,reset trip,turn them back on one at a time.

 

[Diabalo]

Disconnect one of them

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[Spriddler]

If it is the water heater element that's tripping the power, either don't turn the water heater on or just disconnect it?

 

[Mike123]

Need to find the water heater switch then - any idea where this will be ?

Thanks all for the swift responses

 

[meanders]

You need to trace the wiring and disconnect one live lead. Usually easier to do at the appliance end, but depends on the van. Test, If the RCD stays in, its the device you disconnected, if so try the other. It's just possible that both have a issue and only together do they drop the RCD.

 

[Spriddler]

Need to find the water heater switch then - any idea where this will be ?

It may depend upon the year of the m/h. Presumably you don't have the manual.

This might help as it shows at 15.00 mins how to turn off the water heating.......

 

[MichaelT]

Need to find the water heater switch then - any idea where this will be ?

Thanks all for the swift responses

It's where you turn the water heater on, just set to gas and not electric.

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[Mike123]

Thanks

I can disconnect the wire connector on the water and can go from there.

Cheers

You need to trace the wiring and disconnect one live lead. Usually easier to do at the appliance end, but depends on the van. Test, If the RCD stays in, it’s the device you disconnected, if so try the other. It's just possible that both have a issue and only together do they drop the RCD.

 

[PP Bear]

My water heater has a separate switch close to the heater, so can be isolated. Look around your heater for a switch box, usually with a red light to indicate when it’s on.

 

[meanders]

Thanks

I can disconnect the wire connector on the water and can go from there.

Cheers

If you end up with bare ends on the incoming cable, make sure they are well insulated from each other, and any nearly metal before restoring power. LX tape will be OK but a piece of loose choc block would be better if you have any at hand.

 

[Mike123]

If you end up with bare ends on the incoming cable, make sure they are well insulated from each other, and any nearly metal before restoring power. LX tape will be OK but a piece of loose choc block would be better if you have any at hand.

Sorry - meant to say it’s an latch type connector

 

[Cush]

My water heater has a separate switch close to the heater, so can be isolated. Look around your heater for a switch box, usually with a red light to indicate when it’s on.

Ditto. Mine has a switch like that in the closet above the heater, has one for the ultrastore and electric heater beside each other. Fridge one is next to the fridge at the bottom of a cupboard. 2003 AT

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[Mike123]

Thanks for all the help on this one.

Got back today and hooked up EHU, no trips what so ever.

Not sure what it was but working fine now.

 

[Landy Andy]

Thanks for all the help on this one.

Got back today and hooked up EHU, no trips what so ever.

Not sure what it was but working fine now.

You may find that if you have two water heating elements that one has failed but not to earth. Won’t now trip electrics. But now on half power.
That is how mine is.

 

[Mike123]

Both fridge and heater are working on EHU, so not sure what it was.

 

[Landy Andy]

If a single element has failed like mine, you won’t notice any difference apart from your boiler takes ages when on electric. I just run mine on gas now.