Potterton suprima 50 intermittent lockout :(

[AL]

Had the boiler for about 2 years now, however about 6 months ago it started going into lockout mode, at this time i hit reset and it would be fine for a couple of weeks. However it has gradually become worse, now it locks out practically everyday. Strange thing is, it seems to heat the water for a while then go off? so is it overheating or something? Am i going to have to remortgage to get a plumber out or is there something i can test. I am an electronics engineer and don't mind messing about with the electrics but i ain't going to play with the gas

Many thanks in advance

AL

 

[ChrisR]

If it were overheating it woould go into overheat lockout - see yer instructions for the way the llight(s) go es then. Can't remember!.

Depressing PCB's in these boilers. Lots of problems with cracks in solder joints. Take the pcb oout and inspect and resolder connectors, and relay pins. Clean connection pins andd see how it goes. There are only 2 other bits to change - the hi limit stat and the temp sensor thermistor.

If it turns out to be your board (£230 retail), at I think less than 3 yrs old Potty will come and repair for £170 all in regardless of fault. You can get repaired pcb's for a lot less but I can't recommend them.

A corgi would check the fan is clean and that the air tubes to the air switch are clear - but you aren't competent to do that so it (!). Case seals are important so you musnt go in there.

 

[AL]

thanks for the quick reply, i'll give the PCB the once over. If it's just naff solder joints then it's pretty easy to reflow. I guess it must take quite a lot of thermal punishment. I'll let you know how i get on, cheers!

AL

 

[MANDATE]

I had same problem 18 months ago.
With all power to boiler off I ran seperate lead to fan, which operates a diaphram which in turn make or breaks a micro switch which I checked for continuity.
I also checked the boiler stat and high temp stat and could not find anything wrong, also checked the solinoids on the gas valve and changed the high tension ignition lead and still no joy.
Having run out of things to check the pcb became favourate for the root cause, as I'd heard of the poor history, so I purchased a replacement from 'curzoncare' and found potterton had just introduced a improved version (cost approx £134) and problem cured.(15 mins to change it)
I have examined the old pcb and found cracks in soldering where the terminal posts are fitted (but I had to use a magnifier) so fitting and removing the various plugs on the board may have caused the problem
With a bit of luck you may need only a soldering iron

 

[Baggy]

This is a very common problem with these boilers.

For a recondidtioned board you could try http://www.cetltd.com/, I got one from them for around 50 quid delivered .... did the job nicely.

 

[AL]

Cheers Baggy,

i had a look at the link you posted and it's only about £40 for the PCB reconditioned. I'll have a go at reflowing the pcb myself and if that don't do it i'll get a recon board, for only £40 i can't go wrong, cheaper than a plumbers call out fee

AL

 

[AL]

I had the PCB out yesterday, and gave it a look. It seemed as though many of the larger component leads had dry joints and had small cracks as a result of this plus 3 years of rapid thermal change. I re-flowed all of these solder joints and so far (24 hours) it has gone in to locked out mode. I guess only time will tell if it has fixed my problem, i'd just like to thank everyone for their help.

Cheers

AL

 

[MANDATE]

I assume you mean it has not gone into lockout mode?

 

[AL]

Yep sorry, my typo. It is still working fine , this is the longest it has not gone into lockout for months, so i'm pretty sure that it is fixed, and thanks to you guys saved me a couple of hundred quid which the plumber would have charged me i expect

Thanks again

AL

 

[AL]

Still working. So i am now 100% sure that i have fixed the problem. Top site, saved me loads of money. Cheers again

AL

 

[sorted]

My suprima 40 went into lock out just as above. It came on at times, then not at all at other times , then only heated water slightly at other times before turning itself off! -Frustraing intermittant problem of the worst kind, I ordered a new pcb from www.keeptheheaton.com . p/n 5102160 (replacement of old p/n 407750).Funny how potty don't recognise there was a problem with the old part but decide to revise it!!. It cost 130 pounds + vat + 2.50 pounds for delivery(cheapest i could find) .I ordered it over the net then had it delivered the next day-brilliant!. Some addendum instructions were included on how to fit it which it said was in addition to the users original instructions manual.I couldn't find my original instructions manual but in the end didn't need it- cos it was so straight forward to switch the board over anyway. All you need is 2 philips head screwdrivers - 1 small head , 1 larger head . Simply

a) isolate /turn off power to boiler
b)undo the 3 screws holding on the side casing.
c)old pcb board will swing down into view
d)pull off the 2 spades connectors & 5 connector blocks(noting which way round they fit)
e)undo the 4 small screws that hold the pcb to the case and remove it
f) put in new board and affix using screws removed from e)
g)reconnect block connectors. (notice 2 connectors relocate into 2 slightly different positions on the revised board 5102160 -These are the 2 blocks closest to the LEDS on the board- its very apparent where they fit cos they have different sizes so can only fit into their matching sockets! )
h)reconnect the 2 spade connectors
i)Put on new fascia card on panel (new board has slightly different reset button - so needs a hole- the new fascia is provided with hole in it - see the included instruction leaflet to replace old one)
j)Replace side casing of boiler using 3 large screws removed earlier.

Turn power on and watch the boiler spring to life!
Will take you about 1 hour or so at the very most.

Best of luck.+ no more boiler worries - You will have hot water to shave in the morning etc.
SORTED!!!!

 

[ianh1000]

I had exactly this issue with a 5 year old boiler, I checked everything and thought I had cured it by reseating the 2 ICs on the board, sounds like I may have just been lucky enough to "flex" the joints back.

I will take a closer look if it fails again.

 

[ChrisR]

It can be dirty connector pins - which you would have moved.
Someone at Potty told me "there is no problem with Suprima boards"..
i was appropriately condescending, disrespectful, and defamatory.

 

[breezer]

if you are going to change a pcb may i make a suggestion, if you have a digital camera do as i did , take a picture of it (or two or three)

if not make a note of which plug goes where and which way round