Does this immersion require an RCD?

[HappyHippyDad]

My customer has had a new Immersion fitted (see picture). It is a Gledhill Stainless Lite Plus. Is has dual elements The plumber has wired in one of the elements. It does not work. It does not have RCD protection.

My question is, does this immersion require an RCD? My research indicates that it does, but there is some conflicting advice. I have tried ringing Gledhill, but they are closed today. Are there any components in an immersion that require an RCD, and if so do they have the potential for DC leakage? I am just trying to determine if an RCD is required, and if so whether a type AC would be sufficient, as opposed to a type A.

I realise any wiring buried in the wall will require RCD protection.

 

[littlespark]

An immersion is just an element and a thermostat…. No dc/ electronics… unless there’s a controller somewhere on the circuit for it?

Likely it still needs an rcd for buried cables like you say.
If you don’t use a type A, would that get picked up in a future EICR by an over zealous tester?

The immersion not working…. I take it you have power at the switch there?
Is there a thermal trip in the stat? Small pinhole reset

 

[HappyHippyDad]

An immersion is just an element and a thermostat…. No dc/ electronics… unless there’s a controller somewhere on the circuit for it?

Likely it still needs an rcd for buried cables like you say.
If you don’t use a type A, would that get picked up in a future EICR by an over zealous tester?

The immersion not working…. I take it you have power at the switch there?
Is there a thermal trip in the stat? Small pinhole reset

Thanks LS.

They have agreed to have a new CU, so that's good. I made it clear it was just a good idea and not mandatory, but they are a sensible family and would like the CU upgrade.

 

[7029 dave]

My take is if the water cylinder is existing, and your only changing the element like for like under (maintenance) works then its ok.
But glad your upgrading the CU

 

[littlespark]

I think as soon as “the plumber has wired in one of them…. “has been mentioned then for safety’s sake, RCD it!

 

[EricMark]

I have wondered with my own immersion heater if the type AC RCBO should have been changed, but with little chance of anything touching a live part, not really worried, more worried as to if the thermostat is rated for the supply. I know the immersion heater uses DC, but assume a pulsed DC? But have seen nothing in the instructions for the iboost+ to say either needs RCD protection or that is needs type A or B RCD's if fitted. It works well, so have just left it alone.

 

[richy3333]

what are the instructions saying for this tank? the primary element is usually the bottom one and the top one is a 'top up' - based on economy type tariffs. Its a simple circuit so unless there is some form of controller in circuit and the thermostat is set then it should work?

 

[newfutile]

I have never seen a dc immersion,(RCD) Residual Current Device is always a good idea with anything that mixes water and electricity, I have seen loads that develop pinholes or leak eventually

 

[EricMark]

It seems there is a bridge rectifier in the iboost, and a large switching device, so it does seem the output is pulsed DC. Watching a video on one being repaired was what showed me output is pulsed DC.

I have a problem with type A rather than type AC RCD's as other than EV charging units, there seems to be no DC monitoring, and 6 mA is very little, so even with type A the DC could be well over the limits.