Biasi M90E 24S . My Boiler has stopped firing-up.

[KelvinFive]

I would be very grateful for any help or advice on the following.

About 3 weeks ago the boiler stopped igniting when a tap was turned on. To get hot water I just switched on the central heating. Or if the central heating was set to auto and already running we got hot water out of the tap on demand no problem.

At the time it did occur to me that this would probably be a problem that would only get worse.
...well it has.
We have no ignition now.

The boiler makes all the usual sounds apart from the final woosh to light the boiler.

I am not familiar enough to identify the specific sound of the pump or fan but like I said all sounds as usual.

‘A10 Boilers’ fitted a new PCB and Fan in June 2009 and I was devastated by the high price. £548.25.

If this is a PCB issue then I'm quite happy switching it for a refurbished board myself. However if it's anything else I will need help.

My question is:
Are there any simple things I can do to diagnose the problem?
Should I just go ahead and switch the PCB for a £50 refurb “eBay” board because its so much cheaper and would rule out one problem?
pcb (BI1305101)

At no time does the red “lock out” light come on.
The green light flashes every second and after 15 seconds has a red glow behind it.



Thanks in advance.

 

[Deleted member 221031]

Sounds like the pressure proving switch isn’t activating

 

[KelvinFive]

Thanks nwgs.

Is the pressure proving switch the same as the "air pressure switch" as attached image. If so would you recommend simply replacing it?

 

[muggles]

I'd recommend getting a Gas Safe Registered Engineer in to test it properly and replace it if appropriate. It's a safety critical component which can only be accessed by removing a cover that you're not supposed to be removing as a DIYer. Forum rules dictate that we can't give DIY advice on gas and safety critical boiler components

 

[KelvinFive]

Good to know thanks. But more importantly is that the problem?
I'm hoping I don't have to shell out for yet another PCB.

 

[ianmcd]

No that is not the primary flow switch and you shouldnt be touching that, the flow switch you are looking for is part number 24 on page 11 of your manual

 

[KelvinFive]

So the "pressure proving switch" is the same as the "Primary flow switch"?

 

[ianmcd]

So the "pressure proving switch" is the same as the "Primary flow switch"?

yes both the exact same thing, some manufacturers use different names its function basically is to make sure the pump is running and there is a sufficient flow of water through the boiler before allowing the burner to light

 

[KelvinFive]

Ian there is no need for you to concern yourself with my safety.
Your post is very confusing as no one has mentioned the Primary Flow switch.
Also your page reference sheds no light on the problem page 11 of both user manual and service manual attached.

What manual are you looking at?

 

[ianmcd]

https://www.biasi.co.uk/assets/public/user_manual/24/Riva Compact_User and Installation.pdf

 

[KelvinFive]

Cheers I probably should have said it's the PARVA Model not the RIVA COMPACT.

 

[ianmcd]

https://www.biasi.co.uk/assets/public/installer_literature/32/Parva_User Manual.pdf

page 10 Item 24 they are virtually the same boiler

 

[KelvinFive]

Fixed. It was the fan. Tony fixed it with no more than a couple of squirts of silicon spray.