Worcester 24i - No CH or HW - not firing

[timcunnell]

Hello! I have a Worcester 24i. It is not firing. With the front panel off I have tried firing it up, but cannot see any spark from the "sparkie bits" (technical term!).
Pressure is stable (just under 1 bar). Boiler makes a couple of clicking sounds when I power it on/turn on the hot tap, and the fan spins okay.

Oh yeah - there is also a really annoying frequent whining noise. But this is coming from the missus, who keeps complaining that she can't take a shower!

 

[COG]

IF your fan is running the you could hav a flue fault, your air pressure switch should pick up the air movement through the flue then start the ignition so check visually that nothing at all is blocking the flue terminal.If your boiler has a black air pressure switch as originally fitted then have your fitter replace it ,the llater white ones are ok.PS dont try blowing down the tubes to see if it works its limit is only 60mb,

 

[timcunnell]

Thanks very much! I jad pretty much decided to go and buy a new PCB, so this has saved me time and money!
I have removed, cleaned and re-fitted tubes connected to the air-pressure switch and this has done the trick. Boiler working like a dream!! Thanks COG!

 

[timcunnell]

Further to my previous post - it is playing up again! But now I can tell that the air pressure switch is definately to blame. The boiler is behaving erratically, and I can actually hear the air pressure swicth clicking on and off. I guess that just checking the tubes is not enough! But I had suspected this, and shall replace the air pressure switch tomorrow.
This looks like a very simple task - is it as easy as it looks?? Surely a case of removing the old one and installing the replacement? Is that it??

 

[COG]

As long as you replace it with the corect switch "part number 87161424140 " then you will have no problems the new switch comes complete with new wireing instruction if you have the old black switch.if you do wire it wrong it will fail safe.Im giveing you the part number as its obvious your doing it for your self and if you fitted the wrong switch that would be DANGEROUS.

 

[ChrisR]

Of course it could well be that the pr switch isn't faulty at all, but the fan is covered in fluff so isn't generating the required pressure. This is typical of a diyers incompetent dabbling in something which could be dangerous (anything around thd the flue), changing the wrong part, etc.

The correct sequence is
A) diagnose the fault
B) change or clean the correct part
C) TEST FOR SAFETY.
Sounds like A and C are being ignored as well as part of B.

If the appliance were serviced properly the "fault" may never have developed.

Don't get me wrong I DO respect COG's knowledge and intentions here, but may be we should have a standard answer "Stop pratting about incompetently with stuff you don't understand"?

SPAIWSYDU!

 

[timcunnell]

Thanks very much COG for your reply. I shall get the switch today and see what happens. You have been most helpful, and I am very grateful!

ChrisR - I completely understand what you are saying. Boilers are not toys - and should only be serviced by proper CORGI engineers. I don't disagree with you. I think however, that this site is designed for people who...
- Have some decent plumbing knowledge (but are not CORGI'd)
- Have some appreciation of what is potentially dangerous and what isn't (and will leave the dangerous stuff to the experts).
- Simply cannot afford to call out the experts for every little problem.
I feel I fit the above, and have consulted the Service manual (not the user manual) before dismantling anything, and have correctlly followed the fault-diagnosis sections.

I am sure you are a registered CORGI engineer, and as such it isn't wrong for you to point out that people should not just have a crack at fixing boilers in the same way my mum might "have a crack" at putting up a shelf. But I think 99% of the people on here know that, and wouldn't risk their lives.