Saunier Duval Semia Condens F24

[jasewood]

Can anyone help.
I've been out to a Semia Condens F24 and its not rectifying.
after 6-8 secs it goes to lock out.
I noticed the probe was damaged so I replace..I disconnected the condense earth lead. checked gas pressures..
all ok. I spoke with Saunier who said it was prob ignition pcb. I fitted one and still the same..
With the ignition box off and my multi meter in the top and bottom connections where they plug onto the gas valve I get 180v for a second the drops out.
any ideas..

 

[Billy Bob Bob]

test the probe AND lead for continuity before replacing pcb,s

 

[jasewood]

thats the first thing i did as the probes (come with leads attached) were damaged so replaced..
didn't work so I changed ignition pcb..
still not rectifying..

 

[Billy Bob Bob]

Removed
looking at this,it has a trap sensor simple screw type connection? is it sound would have thought theres only continuity here if the conden backs up,you have proven continuity on the detection electrode and lead,is the gap right? is it cross lighting?is it arcing trough a bad gromit on the combustion box?you have replaced pcb,is it just the one fitted finally and importantly all these checks dont mean a thing if you have reversed polarity if you have not checked for this it will give these symptoms and blow your new pcb

 

[mickie]

made sure the airswitch is ok ? ive done one where it let the boiler kick in for a second than off.. annoying

 

[jasewood]

tested everything in manual. Inc polarity and linked out condensate sensor
manufacturer said gas valve but checked.
will try linking out aps.

 

[mickie]

i know that feeling you get after spending 100 quid on a pcb and it still not working..

always best to buy the little things first, thermistors etc..

 

[SafeGasInstall]

did u check gas valve solenoids

 

[mickie]

how is that possible ? i'd love to know 🙂

 

[SafeGasInstall]

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[mickie]

If the ignitor glows for several seconds (up to 15 seconds) and then goes out, the problem is probably the coils (solenoids). If the ignitor glows and stays on, then the problem is usually the flame sensor. If it ignites and then quickly goes out, it is most likely a problem with inadequate air flow

does this apply ?

 

[mickie]

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top man, never seen one before, cheers

 

[jasewood]

doesn't glow as only on for 6-8 secs as its not rectifying.
even with the casing off it's the same.

 

[SafeGasInstall]

Keep coming back here and you will learn
Lot of things to help you grow your
Business 🙂 🙂

 

[SafeGasInstall]

It well could be air switch !!!

 

[mickie]

the air switch has continuity with the fan running ?

 

[jasewood]

thanks for all your help.
gonna try link out the aps and will report back.

 

[SafeGasInstall]

if it's do not leave it bridge and to go back next day to change it

 

[Billy Bob Bob]

it could well be the aps they fail like this on the performa he,dont know what type is on this boiler but probably be able to get it here [DLMURL]http://www.abcotuk.co.uk/subcategory.aspx?catid=C2-14[/DLMURL]

 

[jasewood]

would never link out and leave as it's a safety device.