Worcester Combi Fault

[tvrjohn]

Hi
Having problems with a 28 CDI combi, and would like some ideas on what is the specific solution PLEASE

Central heating stops working and 'domestic hot water demand indicator - flashing fast red light.

ok Manual says its Air Flow Fault (RSF) , Flue Gas Spillage (OF) what do these mean ?

Tried the on/off and press reset button for 5 secs, makes no difference, still flashing.

Took covers off, nothing obvious

Can manage to restart it using this technique !

1, switch main power to off
2, switch on
3, turn hot water tap on and off until ignition sequence starts

sparks and lights burner to supply hot water demand, then switch central heating demand on, can then turn hot tap off.
This then ensures heating is on, but it goes out after maybe 2 hrs
and flashing hot water demand light problem returns.

Note, strange that it will not attempt to light the burner, by demand from the central heating

Look forward to any comments, explanation of issue
Thanks, John

 

[Slugbabydotcom]

Cant be certain without seeing it.
I'm assuming yours is the fan flue version and its the old 28CDI

A common scenario on these is that the fan runs slowly or not at all.
A drop of oil on the fan bearings will often get you going and buy enough time to obtain another fan.

EDIT
Just read the rest of your post and had a bit more thought.
There could also be a diverter valve problem but eliminate the above first.

 

[tvrjohn]

Slugbaby thanks for prompt comments

Yes it is fan flue type, no issues with fan, runs really free

Why might it be gas diverter, ?