Hi My boiler is working intermittently...Can you help?

[Mattfode]

Biasi Model: M96.24SM/B
G.C. No. 47-970-25

Hi My boiler is working intermittently and unpredictably, it can work for days fine, and then I am switching it on and off every twenty minutes or so…

There are three lights labelled:
I, II, III,

When working:- I = Green, II = off, and III = Green
When not working:- I = Green, II = Red, and III = Green
The flame goes out but there is no flame lockout light on and the red lockout button does nothing to reignite ( this is a separate light and button from the ones labelled I, II, III).
But it starts up fine when you turn off and back on.
Can you give me some advice.

I won’t be looking at it myself but I want to be sure when I get an engineer in to look we start in the first and best advised places before it becomes expensive (I know a lot of trusted engineers, but I don’t have a lot of money)
Hope you can Help me.
Thanks in advance,
MATT.

 

[Agile]

In normal operation there are two modes, CH with the two green both on and DHW with the two greens flashing alternately!

All three lights on constantly is usually a PCB error.

The PCBs are pretty expensive too!

Tony