Faulty electrical heater

[gaz1234]

Hello
Looking for some advice.
I recently had a 4kw heater (2x 2kw) installed by a professional electrician. Was good until the it rained and the unit started to trip the rcd. We promptly engaged with the supplier who in turn got in contact with the manufacturer. The unit was ip65 rated and they confirmed its rain proof.
The unit was returned for diagnosis of which the original fault was not found as they hadn’t tested fully. During this time I’m getting mixed messages from them.
Any advice here going forward to try and resolve?
Thanks

 

[conny]

Was it installed outside? If so, was it connected to an suitable outside socket or hard-wired in? If it is IP 65 it should have been able to stand up to quite a lot of powerful water hitting it.
Unless of course the "professional electrician" failed to put back or damaged any weatherproof seals he may have removed.

 

[gaz1234]

It was. It’s designed to new installed outside (wall mounted).
Yes it’s been installed correctly, with ip rated boxes and its own Fuse on the board.
There aren’t any seals that could of been taken off

could the fuse in the board be faulty or the rcd (is that the main fuse?)?

 

[ericmark]

We are told we should test leakage and for a group of circuits on a 30 mA RCD it should not exceed 9 mA, and for most circuits 3.5 mA is the limit, between 3.5 mA and 10 mA there are special conditions.

But it is common with domestic to have many circuits on one RCD, although we have RCBO's so each circuit has it's own RCD it gets expensive.

With IP65 rain should not affect them, but it may affect some thing else. The problem with electric boxes is if filled with air heat expands the air and cool contracts the air which can then suck in water, often we have a small hole at bottom so there is no pressure differential and water will if drawn in be pushed out again at bottom, but this is not IP65, so with IP65 it has to be able to hold its seal under pressure differential, so slightest error and it can fill with water.

A leak at top and it will not expel water when heated but will suck it in as it cools.