Worcester 24si 11 - not working

[beesley121]

Hi guys,

im after some help please

got a worcester 24si 11, hot water working fine but when hearing switch on, it heated up then after about 15 mins it looked out. Light flashing 4 times per second. Tried to reset but fan tried to spin then stopped snd it locked out again. bypassed aps and it fired up fine obviously without the fan running. I thought pcb was at fault not tell fan to spin on ch mode.

changed pcb today and it now flashes 8 times a second, I then try to reset it and it then flashes, times a second and then repeats.

Any ideas

 

[goz666]

Not sure I understand but if it fired up ok why not just replace the APS.?? There's a pretty comprehensive fault finding chart in this boilers manual, ignore the bit when it mentions code plug though.

 

[beesley121]

Fan wasn't spinning in ch mode, so blew down aps, boiler fired up so its my thoughts were because the fan wasn't spinning, it was pcb that was the issue as fan resistance checks out at 121ohms, must be pcb not telling fan to spin

 

[SilentMike]

its a 2 speed fan mate, check hoses aps ect

 

[bewsh]

Ye, it's 2 speed, runs slower in c/h
Make sure the fan isn't caked with dirt, may be running too slow.

 

[arran197]

You've probably got the wrong pcb, there's 2 for these boilers. They're a pain in the backside these are, pcbs are common on them to go. I've changed a few and have only come across a handful of the boilers themselves.

 

[Millsy 82]

If it's the boiler I'm thinking about I have had a few go down that needed a Pcb and aps.

 

[beesley121]

Well with new Pcb attached, the fan does not even try to spin, just does straight to lockout

 

[goz666]

Same as Millsy, had one other week that only had 180v to the fan on the PCB, replaced pcb ok for a day or two then called back and fitted new APS, been great since. When I went first time I suspected APS fault but due to the low voltage on the pcb put the new board in, next time I will replace both parts together.

 

[Millsy 82]

Same as Millsy, had one other week that only had 180v to the fan on the PCB, replaced pcb ok for a day or two then called back and fitted new APS, been great since. When I went first time I suspected APS fault but due to the low voltage on the pcb put the new board in, next time I will replace both parts together.

That's what I do now. Just because I've looked like an idiot on a couple of occasions having to go back and say I need to replace a aps as well!

 

[bewsh]

If the fan doesn't spin, the APS could by stuck in the closed position?

 

[RoryD]

Am dealing with one of these at present. I replaced the APS and at least it fired then. Further it was locking out after some time. Customer says it flickers (4 x per sec) and will restart with out resetting??? The M.I.'s suggest the thermistor (ch).