Worcester Bosch FS 30 CDI not coming on demand for heat

[ln1234]

HI All,

Weird problem with an FS30 CDI, The boiler does not come on when demand for heat (LR terminal) is on, but I can turn it on manually via the service menu. Heating controls all seem fine, but anyone seen an issue before where it doesn't seem to register the demand for heat and just stays on in idle mode? No errors showing up on the boiler.

I'm thinking it might be a PCB issue?

Cheers

 

[Deleted member 120897]

If you can turn it on via service menu, I’d say control issue. Easy way, join the wires together , if it comes on you know it’s control issue (thermostat).

 

[ShaunCorbs]

If you have 240v on lr then something wrong with the boiler diverter working ?