Baxi Solo 3 PF50 boiler - Chattering relay fault

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Hello,

I have Baxi Solo 3 PF50 boiler with this problem - chattering relay when there is no heat demand - it has developed over the last month or so. Boiler is only 2 years old.

First off, I am an electrical & electronics engineer c 20 years experience.

I read that there is 'a known problem' with this PCB and that new replacements are modified.
Q) Can anyone tell me what these Mods are. There is no way on earth I am going to pay £120 for a) Someone's bad design (MY company would NEVER do this) and b) Pay that much for something that would cost less than £10 to make. (<- Don't argue the toss with me about this).

I also read that this is down to 'Capacitors'. That I can understand, poor quality electrolytics. I will simply replace them all for the cost of... nothing.
Q) Does anyone think this will actually solve the fault. Is this the 'known fault'?

Many thanks,

Andy

MOD 2

see rule 20

your post has been split
 
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underwurlde said:
I read that there is 'a known problem' with this PCB and that new replacements are modified.
where did you read this?
 
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where did you read this?
...From a chap on this site called 'raden' who apparently professionally fixes these control boards.

Anyway, after reading some of his posts, he mentioned that when he gets these boards in for repair he 'replaces 7 of the electrolytic capacitors as a matter of course'.

I took this on board and replaced ALL of them. Firstly, I was utterly STAGGERED at how many of them were actually faulty / on their way out (at least 5 of them). I was also utterly staggered at how many dry joints I found on the PCB, so I spent 10mins searchin out & touching up the dodgy ones.

15 mins later.... one perfectly working Control PCB.
COST: nowt
Bloke from CORGI: -£120 and that's just for a replacement control board, no mark up!

regards,

Andy
 
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So why say it? But, whatever. Obviously some kind of 'history' there... ;)

I'm glad this fourm has helped me out and thanks for those who have taken an interest in my thread.

Regards,

Andy
 
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I don't know about a known problem in general but i have changed 2 in the last 2 months for that very fault. (well loud it was) :LOL:

If you ask baxpoti nicely he will tell you the part No of a supressor which is meant to sort it(connects between switched live and nuetral).
 
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Thank you, but I have (I hope, it appears I have) fixed the problem by toutching up the PCB solder joints & IMO more importantly changing out the electroytic capacitors.

OK, put it another way, for the last 2 years, the system has been running fine, and then this fault develops on the PCB (chattering relay). This is why I concentrated on finding a fault on the PCB and it appears that this is the case.

Regards,

Andy

PS
I get the feeling I'm entering into a 'hot debate' about this issue.... :cool:
 
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Heard a while back that you cannot repair pcb`s and refit,something to do with it not being tested to manufacturers spec.Is this true?
Realise what the OP does on his own boiler doesn`t apply but does it apply to RGI.s ?
 
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Andy - any self-appointed "authority" or jobsworth will tell you that you shouldn't touch anything ever, etc. If you delve into the Gas Regs you can find prases which do support that. (GSIUR)
IF the thing blew up and it was because of failure of a capacitor you/I had fitted, I don't think it would help to tell his honour that you thought it was OK.. So any professional is taking on a technical risk he needn't. And he makes more money (presumably) if he fits a new board.

I was utterly STAGGERED at how many of them were actually faulty / on their way out (at least 5 of them). I was also utterly staggered at how many dry joints I found on the PCB
So was I, but only the first time. The quality is awful, on many boards, especially baxi/potterton and a few others, and it's designed that way. Some components work AT their max ratings, and relays are marginally spec'd too. Did you notice the sizes of some of the holes in the board - huge!
Makes the manufacturers more money from parts than from the boiler sale.
 
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Great post Chris: You are a person who thinks like me it would appear!

My job is a Product Engineer. I design safety critical products (for the medical industry), so I am fully aware of the safety implications. One could argue that 'boilers' is not my area of expertese and they'd be correct.

But is this an issue? Not really. I know so much about poxy capacitors (and NO, it is NOT just a simple matter of matching the capacitance and the working voltage) that I consider myself 'anal' on the matter. But then again it is my job to know. I am therefore quite happy that I have MATCHED the exisiting components (in fact they are a damn sight better than the orignals).... I have not altered, modified, improved or otherwise changed the design of the product.

So was I, but only the first time. The quality is awful, on many boards, especially baxi/potterton and a few others, and it's designed that way.
It would appear so. I have been 'doing this stuff' for long enough to see when someone has taken the effort to physically design in the inherent crap in that God awful control board.

Makes the manufacturers more money from parts than from the boiler sale.
Copy and paste this into the car industry, white goods....

Note this week I have fixed:
1) the hinge on my 'new' (1.5yr old) Hotpoint washing machine
2) The motor start capacitor on my Hotpoint tumble dryer (it actually CAUGHT FIRE).
3) This bloody boiler.
4) My yamada DVD player (ribbon cable fault)

Oh, and my 'top end' Sony VCR has finally decided to croak it.

So, how much would it have cost me to have gotten that lot 'professionally repaired'? 400 friggin quid? And I bet not one of those 'Professional Reqpair engineers' have a masters degree....

Andy
 
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