Baxi Bolier, RCD Tripping before bolier starts

[simms5280]

Can any of you help?

I have a Baxi solo WM 30/4 Boiler.

Whenever i turn on the central heating or hot water, after 5 - 10 seconds the RCD trips out in my main consumer unit.

The pilot light still stays alight at all times but does not kick in when the central heating or hot water is switched on, it just trips the RCD.

I have checked the wiring from the thermostat control to the boiler and the connections in the boiler and all seems ok.

I did have some trouble with the 3 way change over the other day, when i had the central heating on i switched on the hot water and the central heating became twice as hot and no hot water, i manually reset the change over (by pulling the lever on the side) and this seemed to cure it for a week and now the RCD trips.

Could these be related?

If not can any of you give me any ideas

Many thanks in advance

Michael

 

[EliteHeat]

Yes, almost certainly your 3-port valve is responsible. Might be the pump though. It takes a few seconds for the valve to motor into place at which time the electrical connections are made via the microswitches - this is when your RCD trips.

 

[simms5280]

Thanks for the prompt reply,

I will replace this first, if still no joy i will try the pump.

Thanks again

Michael

 

[simms5280]

No luck when replacing the 3 port value, I am still experiencing tripping

A friend of mine has mentioned the PCB, because he had a similar problem and the PCB had to be replaced.

Could this be the problem?

 

[gas4you]

I would check the fan or pump first. parts with motors are prime suspects for tripping rcd

 

[Paul Barker]

What a competent person would do is unplug the pump and the fan and gas valve (electrically) then see if it trips, if so it's the board, if not, plug in pump, does it trip, it's the pump, etc. Or feed pump then fan seperately from 230v, does it trip? New one.

The 5 second delay could be the time taked for mid pos valve to move into place or it could be the time taken to get to the part which is tripping, but there is no point guessing, it needs a competent person stood in front of it, who is able to hear what and when the boilers is doing so telly off, staffy in the garden kids to granny';s and keep your trap shut while he's trying to work..

 

[shawd]

What a competent person would do is unplug the pump and the fan and gas valve (electrically) then see if it trips, if so it's the board, if not, plug in pump, does it trip, it's the pump, etc. Or feed pump then fan seperately from 230v, does it trip? New one.

The 5 second delay could be the time taked for mid pos valve to move into place or it could be the time taken to get to the part which is tripping, but there is no point guessing, it needs a competent person stood in front of it, who is able to hear what and when the boilers is doing so telly off, staffy in the garden kids to granny';s and keep your trap shut while he's trying to work..

The pump has gone if the rcd keeps tripping full stop

 

[Gas2Air]

Maybe the OP has fixed it by now shawd the post was 2007?

 

[shawd]

Maybe the OP has fixed it by now shawd the post was 2007?

mate i can fix boilers but this computer stuff i am still gettin my head round