Suprima - unusual (to me) fault

Has worked fine for some time with its latest refurb board from CET but out-of-the blue failed to start the other morning.
As I still had the very first PCB the boiler came with (changed due to usual intermittent lock-out issue) I put that in and hey-presto, it worked!
However, when I first turned the mains on I was getting a flashing red. Pressed rest and away it went.
Got another board from CET this morning, put it in and same flashing red light on power-up and I can't get the board to reset. Put the very original (very first) board back in, powered on to flashing red again but it reset and away went the boiler.
I'm trying to reset with CH & HW off at the programmer and with the boiler stat off.
The fault finding flow chart says things like check pump wiring isn't reversed but it's worked fine for years and indeed is running at the moment.
Anyone have any ideas, please?
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On 01/02/2018 12:02, Rory snipped-for-privacy@hotmail.com wrote:

Asking Geoff at CET might be your best bet...
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I did that. He was somewhat baffled.
Been away for 24hrs and been thinking about it and I wondered if the pump electronics might be causing an issue perhaps together with something marginal on the PCB.
I set it the boiler to come on at 7PM tonight and got home at 9 and it was running - and this is still with the original PCB in!
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Well, this is all a bit weird - it's run for four days now with the original PCB fitted (a note I'd left with said removed in 2004). I've turned the power off and on and it came back on fine, without needing to be reset.
I want to put the 6mth old refurb and the new refurb boards back in and see what happens but I'm loath to touch it while it works!
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On 06/02/2018 19:19, Rory wrote:

Given its winter, "if it ain't broke, don't fix it" springs to mind!
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John.
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Certainly what I was thinking.
It was quite iffy yesterday. It started fine but then, unusually, went off at some point not long after. So it was cold when we got up, and I wasn't popular. I reset it and it started then cut out again a few mins later. N ormally once it's going it runs until it hits the boiler 'stat.
After that it was fine all day. Today it ran perfectly until about 11.30 w hen I noticed it was going chilly and found it was flashing red. It reset a nd ran fine.
What's different about these faults from the usual Suprima lock-out is it's going straight to flashing red - it's not doing the 3 tries at igniting (o r re-igniting).
I do need to bite the bullet and try the other PCBs again, as at least one of them has to be exchanged back to Geoff.
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On Thursday, 8 February 2018 14:17:27 UTC, Rory wrote:

ff at some point not long after. So it was cold when we got up, and I wasn 't popular. I reset it and it started then cut out again a few mins later. Normally once it's going it runs until it hits the boiler 'stat.

when I noticed it was going chilly and found it was flashing red. It reset and ran fine.

's going straight to flashing red - it's not doing the 3 tries at igniting (or re-igniting).

e of them has to be exchanged back to Geoff.
maybe tapping the pcb with a bit of plastic or squirting it with freeze spr ay couyld narrow down a bad joint
NT
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Just thought I'd update this - I limped along with my original PCB. I had tried prodding it - a plastic baby spoon worked well! - and found two of th e relays clicked when nudged, so a bit of gentle 'packing' helped them work .
I decided to bite the bullet and get another refurb board. Low and behold it worked fine.
Quite why the first replacement didn't work at all I don't know. I've read of this before with Suprimas but hadn't thought of it my case, I assumed th e fault was elsewhere. I guess there's something about the parameters the board checks on power up and maybe some are more fussy than others.
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That suggests a dry joint somewhere - or a broken track which makes when flexed.
My first approach would be to remove the board and re-flow all the joints.
If it is a multi layer PCB, make sure any through hole stuff flows to both sides.
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*Change is inevitable, except from a vending machine*

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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On Thursday, April 12, 2018 at 4:44:03 PM UTC+1, Dave Plowman (News) wrote:

Thanks, yes, I did have a go at the board years ago but these Suprima boards are very delicate and from reading of others experiences it's common to lift pads and even tracks. So I wanted to not molest this board further and keep it a known 'good' board.
The one I got from CET that didn't work in my boiler was pretty heavily reworked, with quite a lot of links and bridges.
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That would happen with careless replacement of components - not re-flowing existing joints.

Sounds like it had a short somewhere that wasn't protected by a fuse.
If they really do save pennies by using an ultra lightweight material for the PCB and tracks, would be a make to avoid.
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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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On Saturday, 14 April 2018 00:18:12 UTC+1, Dave Plowman (News) wrote:

I think all boilers are makes to avoid bar Vaillant & WB, simply on grounds of reliability.
NT
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The PCB on my Viessmann is made to an excellent standard. I know this because I've replaced a PCB type fuse on it. But then, so are most goods. I've never really come across one I'd describe as being made from a poor quality PCB material.
Of course like all PCBs they can have burnt etc tracks if not fuse etc protected, and you have a component or whatever fail short circuit. Or it gets badly overheated.
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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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On Saturday, 14 April 2018 10:59:35 UTC+1, Dave Plowman (News) wrote:

none of that tells anything much about its reliability of course.
NT
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I was replying to a post about perceived build quality of PCBs.
Stating a particular boiler is just great in your own experience is of limited value. You need statistics for many to get a truer picture.

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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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On Saturday, 14 April 2018 13:18:55 UTC+1, Dave Plowman (News) wrote:

I thought the Which report on boilers was well known round here.
NT
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If it gives reliability results gleaned from owners, can be a useful guide. Not so much for a new model.
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*Everyone has a photographic memory. Some just don't have film*

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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On Saturday, 14 April 2018 15:57:36 UTC+1, Dave Plowman (News) wrote:

No, but still useful enough to know what companies to avoid. Maybe 1 or 2 of the not so good will get their act together at some point, until I'm not buying.
NT
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On Saturday, April 14, 2018 at 5:35:15 AM UTC+1, snipped-for-privacy@gmail.com wrote:

You see plenty of "they don't make 'em like they use to" comments on both those brands. WB sell a lot of boilers but it does seem that if you get a bad one it can be a right pain with recurring faults.
Boiler fitters like WB as in the event of a problem during installation their support is excellent.
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On Sunday, 15 April 2018 12:52:06 UTC+1, Rory wrote:

Sure, they also have significant room for improvement.

availability of spares is the best for WB.
NT
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