Suprima - unusual (to me) fault

[Rorry]

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 reset 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. I'm trying to reset with CH & HW off at the programmer and with the boiler stat off.

Put the very original (very first) board back in, powered on to flashing red again but it reset OK and away went the boiler. Been running (and has gone on and off) for a few hours now.

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. The pump is an electronic one and should show a fault code if there's anything wrong with it.

 

[SavageW]

If you have an Alpha 2 pump (some earlier ones caused nuisance lockout with suprima’s) can’t think off top of my head but it was identified via code on the pump

 

[Rorry]

I did used to have an Alpha but it didn't last very long and for the last 3 yrs have been running with a Wilo Yonos Pico.

I did wonder if the electronics in the pump might be interacting with some other marginal issue and so cause a problem. The way the Suprima stops and starts the pump every time the boiler fires has always seemed like a good way of shortening the pumps life, and on the Alpha it was really noticeable that it re-started on full speed and then throttled itself back.

 

[Rorry]

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!

 

[Rorry]

Just thought I'd update this in case any other desperate owner finds it on a search!

I limped along with my original PCB during the recent cold weather but decided to bite the bullet and get another refurb board. Low and behold it worked fine.

Quite why the original replacement didn't work, I don't know. I've read of this before with Suprimas but hadn't thought of it my case. I guess just something about the parameters the board checks on power up and maybe some are more fussy than others.