Baxi Bermuda BBU 15 condensing boiler problem

[scooby2]

When the boiler tries to start, the measured supply voltage to it drops to about half and the boiler then stops. This is after fitting a new circuit board after the previous one failed and tripped the circuit breaker.

We suspect it might be the relays in the Siemons controller (Timer).

Has anyone had this problem? Thanks for any help.

BTW We have had a boiler engineer come and look at the boiler, but then say he couldn't help as it is an electrical problem.

 

[ianmcd]

Doubt if it is the boiler that is at fault, I think you have a neutral fault on the boiler supply.
The siemens controller is simply a switch so it wont be that it will be on the electrical supply to the boiler

 

[scooby2]

Doubt if it is the boiler that is at fault, I think you have a neutral fault on the boiler supply.
The siemens controller is simply a switch so it wont be that it will be on the electrical supply to the boiler

Than you for your reply, how do we test for this? I've not heard of a neutral fault before (my husband is the practical and technical one!)