Turning consumer unit on after water damage

[ancienthistory]

Hello wise electricians of the world! I am in the UK. Recently we had a water leak which caused some damage in our home, we are currently trying to dry everything out. The water certainly affected at least some electrical circuits (e.g. water was coming through kitchen ceiling spot lights.)

My plan as a homeowner would be, turn off consumer unit, wait until all has dried out, test circuits, turn everything back on. However my contractor is saying according to regs the consumer unit cannot be turned on for 28 days following water damage to the property, indeed he's saying it cannot even be tested. Seems a bit weird to me. Can someone please help me --- under what conditions can we test and reactivate a consumer unit following water damage to the property? To be honest right now I only want to turn on the breaker to the boiler so the CH can go back on.

Thanks in advance

 

[ancienthistory]

Yes, safety critical components, so this is a given.

Thanks this makes sense. However in our case I think this is exceedingly unlikely since as I say the unit has tested ok, and indeed there is no evidence of any water damage to the consumer unit in the first place.

 

[snowhead]

So nobody knows what this 28 day rule could be?

There couldn't possibly be a fixed 28 day rule anywhere, as 28 days may not be long enough for some flooded properties and may be far too long for others.

 

[Markyd]

Sounds like 28 days is when his sparky is next available

 

[Markyd]

Sounds like 28 days is when his sparky is next available.... If you had a sparks in to do some testing and he was happy, why did he not energize some of the circuits?

 

[cliffed]

Agree with all comments I had a call out to a Care Home the other week water damage in the kitchen, water from roof leak.
Disconnected affected fitting checked elsewhere, left with electric on, returning when ceilings are finished refitting new Led VP fittings.

 

[ancienthistory]

Sounds like 28 days is when his sparky is next available.... If you had a sparks in to do some testing and he was happy, why did he not energize some of the circuits?

He did energize and the main contractor is not very happy about that, and I'm stuck in the middle trying to get my facts straight. Thanks everyone what a helpful community.

 

[littlespark]

My neighbour had a flood a few years ago, and although the water didn’t run through the CU, just the moisture in the air was enough to damage the breakers.

This didn’t stop the elderly father of another neighbour from turning on the power to give them lights…. Even though water was visibly running down pendant flexes.

First thing I did after the homeowner demanded his insurance company had me do the electrical repairs… was to install a temporary board for dehumidifiers.


I tested every length of cable, and only had to replace metal back boxes, new faceplates, new cabling for additional smoke detectors and a new CU at the end of the job.

Although he had a very good electrician… the joiner, plumber and labourer were idiots.
3 core between two way switches on staircase caught with a plasterboard screw. 3 separate water leaks which resulted in another new heat detector… and a gas leak!


Story over. There is no 28 day limit… but the installation needs tested before energising.
If in any doubt, a temp board can be fitted as soon as possible, leaving all of the installation not energised.

Even if the boiler wasn’t affected, damp could damage the internal board…. Or water got into a remote part of the heating system like a room thermostat. Best to leave it off too.

 

[Mike Johnson]

Can someone explain to me why the back box's need changing just because there is some effervescent contamination on them? seems to be padding the job IMO.

 

[nicebutdim]

Can someone explain to me why the back box's need changing just because there is some effervescent contamination on them? seems to be padding the job IMO.

Possibly due to partial loss of sacrificial coating?

Had wondered about this myself as they're unlikely to suffer much corrosion if walls are dried out. Obviously if boxes presented evidence of corrosion to steel, for whatever reason, they should be replaced, but that's more likely to be a historic issue than one caused by moisture over the course of a month or so.

 

[davesparks]

Can someone explain to me why the back box's need changing just because there is some effervescent contamination on them? seems to be padding the job IMO.

If the galvanised coating of the back box is damaged and the box has started to corrode then it is likely to continue regardless of how dry the wall is at any given moment.

It is sensible to replace everything which has been damaged by the flood.

 

[nicebutdim]

If the galvanised coating of the back box is damaged and the box has started to corrode then it is likely to continue regardless of how dry the wall is at any given moment.

It is sensible to replace everything which has been damaged by the flood.

I took it that Mike's point was related to undamaged boxes, but I guess corrosion could start at knockouts or where fixings have scratched away the coating.