nightmare intermittant boiler fault

[DIYedboy]

5% of the time my Suprima boiler won't fire up when the programmer enters the timed start.
I have an open vented system in a 3 bed terrace, the programmer and roomstat are both Salus (new), I replaced the honeywell 2 port valve on the CH circuit and put a new PCB in the boiler. The programmer is calling, the roomstat is calling and the boiler just hangs there fast asleep!
To get it to work, I switch off the supply to the wiring centre (I then hear the valve being wound back to it's rest position). When I switch back on and wait a few seconds the boiler does exactly what it's supposed to do n fires up.............what d'ya think experts?

 

[rojaca]

PART NO. 5111603. If the pcb is not of the encased type you've wasted your money I'm afraid though that's not to say that the pcb is necessarilly faulty.
Do you have a multimeter? Can you check if you are actually getting 230v on the switched live to the boiler.

 

[DIYedboy]

Yes, I have a meter n will be able to check that............strangely enough, I've juat come back in, the heating has been on for 3 hours, house not very warm, programmer n stat calling but boiler asleep again (no lights on), so I had to do the old switch off trick again, perhaps this problem is getting worse, surely it can't be the board..........but it wasn't the one you suggested Rojaca, is your encased one THE answer to the Suprima's achilles heel PCB problem?

 

[rojaca]

Never had a problem with a pcb after replaced for upgrade kit. Bit steep but Heateam do fixed price repair and will fit replacement pcb and harness. B.G do fixed price cheaper but have been to many where board has been replaced like for like several times over rather than the more expensive upgrade kit.

 

[DIYedboy]

From my pitifully small knowledge, I thought that if the board was faulty, the red LED flashed and pressing the reset button was needed cos the boiler had decided to 'lock out' or am I wrong?

 

[transam]

does it do the same when you prog' for H.W ????

 

[ollski]

Never had a problem with a pcb after replaced for upgrade kit. Bit steep but Heateam do fixed price repair and will fit replacement pcb and harness. B.G do fixed price cheaper but have been to many where board has been replaced like for like several times over rather than the more expensive upgrade kit.

I always order a recon pcb from bg but have not received on for about 4 years!, I'm not sure they ever exsisted.
Sticking aps? temperature sensor fault??

 

[DIYedboy]

Transam, I don't know about the HW side

Ollski, what is an APS?

 

[transam]

An a.p.s = air pressure switch , if any one else is on here , would it be one of thosr suprimas with a flow switch on the , flow pipe ??? , could that be the prob '??
To the o.p if the fault is with the boiler it should reproduce the fault when H.W is programmed ????

 

[DIYedboy]

Transam, because the fault is intermittant, I never know when it'll happen next but it's easy to know when the rads haven't got warm, and thinking about it, the HW is a bit unreliable so I suppose the fault does occur on the HW circuit too

 

[rojaca]

Your right DIYed boy. That's usually the symptom which is why I suggested at the start that it wasn't necessarily the board. My point was mainly that if you are going to replace the board that its better to get the complete upgrade kit for the bit extra.

 

[kitch0978]

i fitted a suprima pcb couple of weeks back, you get whole nes wiring loom with it too, and side case etc......115quid fitted, we charge 45 labour and put 40% on parts so not expensive at all

 

[Gasman28]

i fitted a suprima pcb couple of weeks back, you get whole nes wiring loom with it too, and side case etc......115quid fitted, we charge 45 labour and put 40% on parts so not expensive at all

£115 fitted? An e-bay purchase?
Suprima PCB's are around £170 odd to buy

 

[kitch0978]

no brand new from part center, i thought it was cheap......but we made a profit and a happy customer! Or maybe office girl got her sums wrong!!!!

 

[transam]

Suprima boards , last time I looked £95 + vat from abcot ???