Subprima 40 boiler Fault

[Engineer2012]

Hi,

I have the above boiler installed in my home.

Today it has started tripping the RCD on the electrical consumer unit but it doesn't trip the central heatings MCB on the consumer unit.

I have 1 thermostat in the hall and one thermostat in the garage, along with the heating controls in the kitchen.

My first thoughts was one of the thermostats were faulty so I disconnected them 1 by one and the RCD kept tripping each time power was applied to the system. When I took both thermostats off and the system controller the RCD does not trip!

I have not tried connecting the heating to a non RCD protected breaker in the consumer unit but I don't know if this would work as there surely seems to be a problem that causes the tripping.

Can anyone suggest a solution or a cause of the fault and how I could check the fault and rectify?

Thanks

Thanks

 

[DBPlumbHeat]

common problem with electrics tripping are pump, 3port/2port diverter and spade connectors to the fan on the older no L suprima's. carry out electrical checks before sticking you hands straight in!

 

[Agile]

Hi,

Today it has started tripping the RCD on the electrical consumer unit but it doesn't trip the central heatings MCB on the consumer unit.

Thanks

Why should it?

They both respond to different types of electrical fault.

All you need to do is to search for existing threads which will give you hundreds of posts about nuisance tripping.

Tony