Ideal Response 80 tripping main RCD

[laesq]

Hi,

I have an Ideal Repsonse 80 combi boiler that has suddenly started to trip the main RCD trip switch when the boiler is on.

When I say on, the amount of time before it trips again varies. If the boiler is left off for a while, I can turn the boiler on (mains switched) and it will happily fire up and you can hear it working away. Then after about 4 or 5 minutes it will then trip the RCD. If I switch the boiler off then, reset the RCD (so power is restored to the rest of the house), if I attempt to turn the boiler back on (mains switch) it will almost always instantly trip the RCD again. But as I said above, if I leave it off for a while (maybe something like 30mins or greater), I can then turn it back on.

Also, if I switch the boiler back on (after tripping and leaving if off for 30 mins), if it isn't required to do anything, as in, no hot water is needed or thermostat is above set temp, it will stay on happily. But when it has to fire itself up and work, I get the usual 4 - 5 minutes worth of time before it will trip the RCD again.

I've done some basic elimination of the thermostat and timer as the boiler has a single input from those devices which can simply be linked so the boiler is set to an 'always on' state for the central heating. It still does the same thing.

The boiler (as far as I know) has been in the property since new, which is somewhere between 8 and 10 years old. Also, I don't think it's ever been serviced in that time.

So I'm just wondering if this is terminal or just a case of needing a service to clear some blockage or something. Any ideas, thoughts or help here would be much appreciated.

Cheers,
Neil

 

[JohnD]

It's probably a combination of wate and electricity getting together.

quite likely a water leak round the pump getting onto the electrical parts.

Or might be a leak in the boiler doing a similar thing.

As it's a combi I presume it hasn't got a 3-way or zone valve? That too is electrical.

Inspection may show traces of a leak

The delay might be because water is drying out, or it might be something is cooling off and will turn on or off again when it gets hot, or might expand and allow the leak to open up.

 

[corgiman]

Probably the low pressure switch leaking

 

[gas4you]

I agree with Corgi. 99% of responses tripping electrics is due to the pressure swithch leaking internally.

Easy and cheap to replace, but make a note of the wires and terminal numbers before removing them.

 

[Agile]

Whilst its usually the LP switch leaking its normally leaking onto the o/h stat and damaging that!

Tony

 

[laesq]

Hi,

Thanks for all the responses so far. Got a CH guy to come and have a look. The heat exchange, once the boiler has kicked into action, gets rather wet around it's base. The guy took the burner out and found there's a large spilt almost all the way around it half way up. Also, he says the tripping looks to be caused by the water collecting around the base of the burner and shorting the three contacts there. He said two are for the ignition spark and one is an earth detector (I think). So the short to earth causes the RCD to trip.

He wasn't very keen on the Ideal Response 80 and said some units he's known haven't even lasted 3 years! So mine at 10 years old has had a good innings. He also showed me how rusty the thing had got inside. One large pipe going from the bottom of the heat exchange to the bottom of the case is very rusty and the screws are barely recognizable!

So he's going to see how much a burner costs and let me know. If it's under £100 I'll probably get it done. If it's more, I'll probably go for a new boiler.

Any thoughts, suggestions on the above?

Cheers,
Neil

 

[gas4you]

With these I would recommend getting Ideal in to sort them out. As they know that they cocked up with this boiler they do special deals on fixing them for you.

 

[corgiman]

Dave is right

I would get rid anyway I hate the heaps of shyte personally