Potterton Suprima 80 not firing for hot water

3 Apr 2012
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United Kingdom
We have a 10 year old or so Suprima 80 which has worked well enough apart from the usual things where it occasionally flashes lights and stops working for an day or so! Always seems to sort itself out though.

Anyway, things seem to have come to a head. It seems not to be producing any hot water at the moment, have had a combo of different lights. First time, solid red, then after lots of resetting, flashing orange and red. Then eventually it fired. Then yesterday, flashing orange indicating external call for heat but nothing. After a lot of resetting it seems to work again. This morning, nothing. Solid orange light indicating no call for heat despite the hw being switched on. No amount of messing will get it to work - however, switch on the CH and it's fine.

Boiler had a replacement board 7 or 8 years ago (single lamp version). Is it the same thing again or could it be something else in the system as it doesn't think there's a call for heat.

Forgot to mention, hold reset for 10s and the red lamp pulses very quickly. Hold it again and it goes back to solid orange. According to Google this means APS/flow switch fault but I don't trust it to be honest!

Have a BG contract so will call them, but any thoughts?
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The first zone valve - we have two of them, honeywells. Edit: 2 ports, not the 3 port pictured.

Can't remember what the contract is - covers boiler and CH, but not drains etc.
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If you have 2 x 2 port valves, the one going to the cylinder is most likely where the fault is, and most commonly will be a failed synchron motor, which is easily replaced. There are other possibilities but testing the powerhead is where I'd start.
OK, can I check that manually? When the he is on but the boiler not firing, move the metal lever myself? Thought I tried that earlier but maybe not.
In all honesty, I would leave the testing and diagnosis to your BG repair man.
The testing requires a meter and a little bit of dismantling, and also a knowledge of S plan wiring.
Hi folks,

It has been OK for the last couple of weeks with the odd slip where we get slow flashing orange lights.

Anyway, called BG and an engineer came out yesterday. He scratched his head and said there wasn't a huge amount he could do as it was working. HW and CH firing fine. He turned the boiler temp down to about 70% as it had been full, and the HW tank stat from 70oC to 60oC saying it might be overheating. Left the timer for HW in continuous so it would just be controlled by the tank stat. Basically said monitor it for a month and record any error states, then call it in and leave it in an error state if possible...

Then yesterday evening I noticed the water was only luke warm. Checked the boiler and had a slow flashing orange light (3 secs on, 1 off). I ran the hot water long enough so that I could hear the HW tank refilling but the boiler still wasn't firing. Restting the boiler and power cyling the mains had no effect at all. Turning the temp control off it made it flash faster orange ("ext call for heat/temp control off" according the to the manual), turning it back on it was the slower flash again. A long (10s) press of reset had a very fast pulsing red light, another 10s press and we were back to the long slow flash or orange. Tried to force the boiler to fire with the CH but nothing doing.

Went back to look later in the evening and it as the red flash once/sec (Lockout). As per the manual, a 10s press of reset gave a yellow light followed by 8 flashes of red, repeated. 8 flashes are not documented as a fault! Repeated the 10s reset, got a yellow light followed by flashing red 3 times/sec ("APS/flow switch fault"). Mains on/off had no effect.

Left it again and when I went to bed noticed I could hear the fan spinning on the boiler. Tapped reset briefly and the red flashing stopped and back to the old slow orange flash

Got up this morning and there seems to be hot water (not scalding, but hotter than yesterday evening so presmably it fired at some stage during the night). Checked boilersolid orange light, but left the tap running for a bit (could hear the tank filling) but nothing from the boiler. Switched on the CH and slow orange light flash started but no CH. Turned off CH and slow flashing continued.

Sorry for being verbose but I have tried to document everything just in case it is relevant.

Not sure what to do. Clearly there is a problem and with a baby in the house and peak gas engineer callout time approaching I want it sorted, but not sure whether to dcument it for a bit longer. The guy said some bits are now unavailable for our boiler so it might need a new boiler. How likely is this? Does it sound like the usual PCB failure or something else in the boiler, or something else completely?

Yours, confused!
Hi I would love to know whether or not you managed to resolve this as I have a very similar issue. After 6 years my Suprima developed the standard red light lockout issue which got worse over 6 months, so I fitted a refurbished pcb and all seemed fine.

That was 18 months ago now, with no problems at all and then last week I lost heating and hot water and was getting the slow flashing orange light (3 secs on, 1 sec off) with the boiler temperature set to its usual level and with CH and HW generating an external call for heat. Never seen that one before.

Electrode lead is new and looks fine. Have tried resets, power recycles, etc etc. In the last week or so on the odd occasion CH and or HW have fired and run for a while but then same problem occurs again.

I am starting to think it might need another PCB, but I hope not.

Any ideas welcome, short of calling out a CH engineer to have my wallet unduly lightened for no good reason.

cheers scorzon
short of calling out a CH engineer to have my wallet unduly lightened for no good reason.

cheers scorzon

Well now, 'unduly lightened', Given that I served a four year full City&Guilds apprenticeship, have to pay 'unduly' large amounts of money to GasSafe Register, Training centres, insurances, provide a van to carry me and equipment, and use skills, knowledge abilities, 'tricks of the trade' to keep people warm and clean, I may well wonder why I bother...

Good job I do not have regular customers like you though, as over 95% of my work is repeat/recommendations etc...

Consider yourself 'Duly Enlightened'

Next time it locked out left it and called British gas. Same guy came out, replaced PCB and it has been fine since...
Oh dreadnought, there's always someone without a sense of humour to tease out into the open. I was hoping for a bite, but you almost managed to reply before I posted - quality!

And I promise, no comments from me along the lines of "95% of your work is repeat business? Surely if you were any good you'd fix it first time!!" I wouldnt stoop so low.

Sorry, but it is force of habit having had a fully specced CH engineer try to fleece me previously.

Anyway, from what fliptop said, I may be changing my PCB again - a happy couple of hours tinkering I seem to recall.

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