Electric showers

[Deanorey]

Hi all im Dean, this is my first forum. So not really sure how it works but here goes. I've just reinstalled an electric shower for the third time in the last 10 years. That's not the issue though. I've used the same make and model to make it easier for reinstillation. But for some reason it's not working. I've tested terminals and power is good. However when I press the power on the shower the light on the isolater goes off 

 

[ProDave]

High resistance burnt out contact somewhere. there was probably nothing wrong with the old shower you just ripped out, if only you had tested first.  Start at the shower isolator switch or connections in the consumer unit. When you find it, it will be pretty obvious charred and burned bits.

 

[NozSpark]

And if you do go into the consumer unit and/or shower isolator make sure it's turned off..

Any burnt / over heated copper cables will have to be cut back to bright copper otherwise you'll have the same problem again quite soon

 

[Andy™]

High resistance burnt out contact somewhere. there was probably nothing wrong with the old shower you just ripped out, if only you had tested first.  Start at the shower isolator switch or connections in the consumer unit. When you find it, it will be pretty obvious charred and burned bits.

+1. most likely neutral terminal on the switch thats faulty and nothing to do with the shower

 

[Deanorey]

Cheers Dave 

I did however check that power was going to all contacts and it was. However in the old shower there was some charring to the negative feed. Would what you say still apply? 

 

[Ruzzeii]

i had a shower a couple of weeks ago and the customer was saying how it did work then didn't work then did work then didn't work, so i looked inside the consumer unit and found the feed in to the MCB was all loose on the busbar , probably like that for ages, surprised it didn't have signs of heat damage

 

[kerching]

Cheers Dave 

I did however check that power was going to all contacts and it was. However in the old shower there was some charring to the negative feed. Would what you say still apply? 

What did you test it  with?

As has been said before.......sounds like high res fault

 

[SLIPSHOD & SLAPDASH]

i had a shower a couple of weeks ago 

Do you pong yet

 

[Ruzzeii]

Do you pong yet

like a kipper

 

[Doc Hudson]

Did you do any dead R1 R2 tests through the isolator switch before energising. I would suggest doing and R1+R2 then compare it with Rn+R2, see if there is any significant difference in the values.  They should be within a gnats whisker of each other, same cable same CSA conductors. Check that the values you get are appropriate for the length of the cable run. Using the milliohm per metre table it is very easy to see if length and resistances match up. If the cable terminations or the contacts inside the switch are in deteriorating I think you will see a higher than expected reading on one of the legs.

Doc H