Chaffoteaux & Maury Combination boiler

21 Nov 2008
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United Kingdom
Hi I've been having problems on and off for weeks with my boiler which is not even 4 years old yet, where the reset button keeps going red, showing that the heating and hot water is not on, basically the boiler is not working and the 70 and 80 lights are flashing, showing the flame is undetected. We have been able to press the reset button and get it working again but gradually this has not worked and now we have had no heating or hot water for 5 days. Our plumber has changed the flow sensors but this has not solved the problem, anyone any ideas?
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Get a service engineer to check gas settings, if ok then look at pcb,detection electodes(i think there is a update with longer probe) this is if the boiler locks out with gas alight, if gas is not lighting then pcb, spark electrode or spark generator, Gary
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90% pcb they had a series of faults with these and the age is about right for it.

If you phone up chaff they will check all the gas valve etc but from experience we have found them to be the pcb. which also comes with a new panel as well if its the mx range.
My plumber changed the ignition switch and leads and got the boiler working for 2 days, its just gone off again. He gave me a quote for a PCB and that was for £161 plus VAT, is that about right? Ive searched a few sites and came across 1 for my model for £41.41 plus VAT plus postage so obviously thats a big difference. Getting a 2nd opinion anyway as not happy with this, its been going on for 3 1/2 weeks.

Is changing the PCB a big job? and do any of you know of a 'decent but cheap' website or place to get this part??
Stick with your plumbers quote, as long as he refunds you if it is not this at fault, or do as I do in uncertain circumstances, I fit the new pcb and leave on test for a week or so, if it all works ok, I then invoice the customer, if not I put the old pcb back in and make no charge for my stupid error in judgement.

I think his quote is very reasonable for a new original pcb fitted with a 12 month warranty.
if thats the price fitted then sounds ok to me.

More of a fiddley job to be honest. as i said before iirc you have to change all the lcd panel as well

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