Heating tripping the RCD

[aldouk]

Hi there,

Have an issue with our central heating, the power has tripped out a couple of times and it did so again through the night. By a process of elimination, I found that the issue was with the heating. As soon as I powered on the Heating switch that is next to our control unit (DANFOSS) in the kitchen, the RCD tripped.

I switched off the boiler (Ideal ICOS HE24), turned the thermostat in the living room to low, turned the controller unit (now on battery power) for heating and for water both to "off" & then changed the fuse.

When I switched it on, same thing happened, RCD tripped out.

Any ideas on what to check next, there is the water cylinder upstairs and I've checked that for any leaks around the pump area (GRUNDFOS pump) and it's dry?

Any pointers or help would be appreciated but I am guessing that I should really call out a heating engineer.

*Edit* There is also a Honeywell T4360A Frost Thermostat in the garage located next to the boiler

*Edit* I've used the r/set function on the controller in the kitchen and also checked all the connections on the main power switch & the frost thermostat. Have changed the fuse & powered on and at the moment it's holding. Boiler has been powered up and no issue yet. Fingers crossed it was just a gremlin in the system

Cheers

 

[Agile]

Most likely to be a leaking motor valve.

You dont need much water to operate a 30 mA RCD.

Worse the water evaporates as soon as the pipe is heated!

Tony

 

[aldouk]

Thanks Tony,

Well the gremlin is back, woke up this morning and again no power. I will call Ideal out to check the boiler for any leaks but this has me stumped as it was working fine through the day.

Cheers

Allan

 

[Agile]

You would be better with a local independent!

 

[aldouk]

I totally agree with you there but I have the Gas Central Heating Breakdown cover with Ideal/Homeserve so I may as well use that.

The power tripped again, noticed that it was as soon as the controller unit seeked heat that the power went off. Had a look at the boiler again and although it starts, there is no longer any display on the front and it doesn't fully fire up.

So it's staying off until the engineer comes out on Friday.

Has to be said that this unit has had 3 pumps, an expansion vessel and multiple control units replaced in the last 6 years, don't know if it's common for this make/model but it does seem to have a reliability issue.

If the boiler is fixed and the problem occurs again then I will be going down the independant route.

 

[Agile]

Stay with Homeserve with that boiler! They are very unreliable.

Whilst the motor valve seemed to be the fault, the boiler now seems to be leaking inside but that rarely trips the RCD.

Tony