Replacing Electric Wall Heater Wire

[dmuk]

The previous owner attempted his own repair job on the Electric Wall Heater. I suspected he moved it and did his own wire extension. Anyway, I am looking to replace the wire.

I am hoping this is an easy job however want to avoid frying anything.

It is a Stiebel Eltron CAEC 750 Panel Heater.

Not certain what replacement wire to purchase. (If I can actually disconnect the wire from the back of the unit?)

I have taken a photo of the fuse box just to seek confirmation on what to turn on/off when performing the DIY.

I am looking for some help on what to do...

Photos:

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[securespark]

Why do you suspect the previous owner attempted a repair, moved the heater or did an extension?

If he has done this, why are looking to replace it again?

Which wire are you looking to replace?

If you are talking about the flex feeding the unit from the pictured switch, that is part of the unit that was most probably fitted in the factory.

The spec. of the cable will either be in the handbook or stamped on the cable itself, or you may have to contact the manufacturers.

Do you consider yourself to have the correct skillset required for the job?

 

[JohnW2]

I have taken a photo of the fuse box just to seek confirmation on what to turn on/off when performing the DIY.

Particularly in view of the warning label on the switch, this is clearly a crucial question - which we may or may not be able to answer. However, I for one cannot really read the circuit labels on your CU ('fuse box'), so could you possibly provide a better piccie?

Kind Regards, John

 

[JohnW2]

Why do you suspect the previous owner attempted a repair, moved the heater or did an extension?

I assumed that the OP was referring to the taped-up join (whatever may be under the tape) in the cable, and that he wanted to replace it with a continuous length of cable (which, as you imply, may or may not be easy).

However, at the least, I can understand the OP wanting to look underneath that tape and, if necessary, improve whatever join exists there.

Kind Regards, John

 

[dmuk]

However, I for one cannot really read the circuit labels on your CU ('fuse box'), so could you possibly provide a better piccie?

I have added close up photos of the box. We have 5 heaters, so assuming that 5 to 9 relate to the wall heaters.

I suspect the previous owner moved the heater in question because it is the only one in the property that sits away from the power outlet. Under the tape is wire extension device. This doesn't look that safe hence looking to improve it.

The wires for all units do not have any markings and I do not have the handbooks.

I guess one question would be how the wire connects to the heater at the back of the unit. This may well explain why the previous owner added an extension rather than just fitting a longer wire.

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[AndyPRK]

Are there just 3 wires in the cable?

 

[JohnW2]

I have added close up photos of the box. We have 5 heaters, so assuming that 5 to 9 relate to the wall heaters.

That would seem to make sense. I can but assume that some of the heaters are supplied by one circuit and the other from the other circuit, and that the warning on the switch is is suggesting that you should switch off both (circuits 5 & 9) before working on the circuit, since it is not clear which supplies which heater. However, that is all speculation - you need a method of confirming that the circuit is dead before you do any work on the circuit. Do you have any sort of test meter and, if so, are you confident & comfortable to use it? Is there any sort of light on the heater which comes on when it is switched on?

I suspect the previous owner moved the heater in question because it is the only one in the property that sits away from the power outlet. Under the tape is wire extension device. This doesn't look that safe hence looking to improve it.

That's what I assumed. However, it's quite possible that whatever is under the tape already represents a satisfactory and safe join in the cable.

I guess one question would be how the wire connects to the heater at the back of the unit. This may well explain why the previous owner added an extension rather than just fitting a longer wire.

Indeed, it may be difficult to access the origin of the cable within the heater - hence the previous owner just extended it. There is nothing wrong in concept, electrically, with extending the cable, provided it's done properly and safely.

Kind Regards, John

 

[JohnW2]

Are there just 3 wires in the cable?

One would suspect so - but since the main thing the OP is asking is how to safely isolate the circuit, hopefully he doesn't yet know for sure

Kind Regards, John

 

[AndyPRK]

You can see the wires under the switch in the photo.

One looks black which would be correct for 4 core and would explain why it says two supplies

 

[AndyPRK]

I suspect Mcbs 5 to 9 inclusive do heaters as there are 5 heaters.

They just ran out of labels

 

[JohnW2]

]You can see the wires under the switch in the photo. ... One looks black which would be correct for 4 core and would explain why it says two supplies

Ah, yes! I can't disagree with what you say, although I'm not sure it makes any great sense to me ...

I suspect Mcbs 5 to 9 inclusive do heaters as there are 5 heaters. ... They just ran out of labels

Good thinking (the OP would hence be advised to switch off all 5 of them, before testing for dead) - but, as above, would it make any sense for there two be two supplies at one switch if each of the (0.75 kW, if all the same) heater had its own 16A circuit?

Kind Regards, John

 

[AndyPRK]

I think the only safe way in this case is to turn off all the red switches and rcd.

 

[JohnW2]

I think the only safe way in this case is to turn off all the red switches and rcd.

Agreed. Quite apart from the uncertainties about the heater circuits, the arrangement of the CU seems a little odd.

dmuk: If you first switch off absolutely everything, as suggested above by Andy, a photo of what is going on inside that switch might help us to get a feel for what is going on.

Kind Regards, John

 

[flyingsparks]

Could be a pilot wire supply from a central programmer or room stat. Dimplex do a heating system like this.

 

[Taylortwocities]

An interesting consumer unit.

It would appear to be a dual tariff one as it has two MAIN switches. From a first glance, it looks like the only thing on the left hand main switch (off peak?) is the water/immersion heater. There is another one on the other side of the CU.

The web site shows the Stiebel Eltron CAEC 750 as a straight panel heater. My guess is that the 5 panel heaters may, at some time, have been storage radiators and these have been swopped out for panel heaters at some time.

That may be the reason for the "two supplies" label if that heater location had a storage rad with a boost convector feature.

This can only safely be determined by a site inspection.