boiler tripping rcd

[COLING]

Hi Guys,
Can anyone help? I have a fairly old Olympic Thorn boiler which has been working fine until I had a new electrical consumer unit fitted with an RCD.For the first 2 days everything was fine but now the boiler keeps tripping the RCD and refuses to fire up. The electrician has checked out the supply to the 3 amp exterior fuse which is ok. From there the supply goes to the programmer where it hooks up with the room thermostat before going into the boiler.Any help/advice would be much appreciated.ThankQ,
ColinG

 

[COG]

The circ pump has the largest load then the gas valve then controls ,seems a bit odd it was ok before the re wire. if you have a new consumer unit your trip should be in the center protecting the heavy loads (skts,cooker,shower) and the smaller more likely to be a nuisance to the other side such as lights,door bell,alarm,BOILER)

 

[Paul Barker]

Unless it's a TT earth in which case the whole house must be rcd protected.

 

[Agile]

Has anyone tested your installation with an earth leakage clamp meter?

Tony Glazier

 

[Alan Carruthers]

Could be a faulty RCD Get it checked by a Part P Qualified person or the system checked on a mega or a Fluke.

 

[chrishutt]

Earth leakage is most likely to occur in CH pump, so if the HW is gravity, you should be able to tell if it's the pump or boiler tripping the RCD. If it's fully pumped, you could disconnect the pump temporarily to test if boiler alone causes trip. If not, I suggest replacing pump.

 

[meldrew's_mate]

Could be a faulty RCD Get it checked by a Part P Qualified person or the system checked on a mega or a Fluke.

Good advice, could also be you didn't have an RCD before and are now detecting leakage which has been occurring for a long time. This should have been picked up when the new consumer unit was fitted.
An RCD tester can "inject" small leakage currents to replicate nuisance tripping, so a registered electrician may be required.

Not sure I should be telling you this but I once had a Glowworm boiler fan tripping the RCD, proved it by temporarily removing the earth lead from it. BE WARNED, don't leave it like this, your whole piping system could become live whilst testing so don't try this with youngsters or oldsters in the house.

 

[Spark123]

An RCD tester can "inject" small leakage currents to replicate nuisance tripping, so a registered electrician may be required.

Do you mean a ramp test? Possible but generally speaking an RCD should be checked when installed at 0.5I +&- to ensure it doesn't trip.

Not sure I should be telling you this but I once had a Glowworm boiler fan tripping the RCD, proved it by temporarily removing the earth lead from it. BE WARNED, don't leave it like this, your whole piping system could become live whilst testing so don't try this with youngsters or oldsters in the house.

Please do not try this, it is dangerous.
Just a thought, although can someone please confirm, can he see if temporarily disconnecting parts of the system i.e. the pump from the C/H system (disconnecting both live and neutral) stops the RCD tripping when powered up?
Please note that although it may not be the case, insulation testing a device which incorporates semiconductors (PCBs) may cause damage.