New Shower Won't Work - Electrical Problem?

[griz]

I have just installed a new Creda Spray Spa 8.5Kw Electric Shower which won't work.

The power light does not come on. There is power on both sides of the power block in the shower which I tested with an electrician's screwdriver.

I don't think there is a problem with the water supply as I originally purchased another shower which is the type activated by a knob controlling the water flow. When the water flows the heater should come on. The water flowed through this shower but would not heat. I adjusted the water pressure + & - but to no avail. I returned this shower and got the above as a replacement.

The Creda has a "Stop/Eco/High" knob and a separate temperature knob. The water won't flow if the heat does not come on.

I don't think the PRV (pressure relief valve) has been activated because that area of the bathroom was bone dry before I fitted the pipework and remained so after completion.

The shower is on it's own circuit from the main board which has a 40A MCB, which has not tripped. There is a separate on/off switch with red neon indicator outside the bathroom. The cable (10mm across) is clipped to the wall/ceiling across the hall into the bathroom. The distance is approx 10/12m. The wiring is approx 25yrs old.

A pull cord isolating switch and RCD remain to be installed.

The previous shower failed with a bang. I can't remember if it was on at the time - I think not but I heard the bang. I usually turn on the shower leave it to warm up and then use it.

So. Is it possible that there is something wrong with the neutral or earth wiring? Do showers detect such problems and if it is electrical how do I go about checking and testing for faults?

Any help much appreciated.

many thanks

 

[ericmark]

To replace a shower when the previous one went "Bang" without testing the wiring would be criminal and anyone who did so would likely end up in court should anyone be injured.

The test equipment is not a neon screwdriver. Although these may warn when mistakes are made they should never be used as a testing device. You need to test with an Earth Loop Impedance tester to ensure the earth has not been damaged. These testers are not DIY kit and you will need to get the testing done for you.

Also to have a shower without RCD protection is also foolhardy. Not sure on date but were required back with BS7671:2001 so around 10 years and to me we all know domestic premises should be checked every 10 years so really there is no excuse for having an installation so out of date.

I fitted RCD's to my house on all circuits back in 1992 as I would have never forgiven myself if any of my family got injured. I think more of my family to place them in unnecessary danger. Myself may be but not my family.

So I suggest to get an electrician and don't place yourself or others in danger.

 

[bernardgreen]

There is power on both sides of the power block in the shower which I tested with an electrician's screwdriver.

First of all you have created a very dangerous situation. Switch off the power to the shower and leave it OFF until the system has been repaired and tested by an electrician

You have power on both sides of the power block ? . Do you mean that the neon screwdriver lights up on both the brown and blue wires ( though with 25 year old wiring it will be red and black ).

That might suggest that the neutral wire between consumer unit and shower has gone open circuit or burnt out. That is a fire risk if you continue to try and operate the shower.

When the neutral wire failed the earth wire may have been also damaged meaning the shower is not properly earthed. That could mean someone working on the shower could be fatally electrocuted.

You have no knowledge of the dangers involved. Switch of at the consumer unit and get an electrician to make it safe.

 

[ColJack]

did you not suspect comething wrong with the electrics when the first shower failed to heat up?


oh and 10mm across? that's what? 2.5mm² T+E? 4mm² T+E at best?..

you need the circuit replaced with bigger cable and an RCD installed...

CALL A SPARKY!!! before you hurt yourself.

 

[griz]

Ok thank you. Message received and understood.


Oh by the way...

My last experience with an electrician was when a neighbour and friend changed her shower. Same brand same model but 9.5kw from 8.5kw. He was there 45 mins and of those 30mins were involved with changing the shower. The charge was £175 and...

No pull cord isolating switch was mentioned or installed;

No RCD was mentioned or installed;

No discussion took place about the wiring.


So you can understand why so many people are so uninformed about these things.

Still we live and learn or in this case we have lived and learn't.

 

[bongos]

Unfotunately there are cowboys out there. It doesn't sound like your friend had a particularly good spark.

You would be best using a spark that is a member of a competent person scheme. They should at least be doing things right - and if they don't you at least have comeback via their competent person scheme.

Have a look here.