On 27 Feb, 19:30, Ed Sirett wrote:
On Tue, 27 Feb 2007 03:11:18 -0800, Neal wrote:
On Feb 26, 9:48 pm, raden wrote:
In message .com, Neal
writesI have a Netaheat profile 60e

Symptoms:
No main burn
No pilot light
Fan is running
no 'sparking sound' to be heard
The 'cutout' (?) button on the bottom is not out (in the past, the
boiler has occasionally cut out, and this button pops out. Pushing and
holding it in relights the pilot, and then the main burn)

Is the fan transferring the air pressure switch from normally closed to
normally open ?

If the APS isn't changing state, then it won't progress to opening the
pilot and sparking

--
geoff

When I switch it on, and the fan sarts up, there is a delay, and then
a click of sorts. - I think this is the air pressure switch tripping?
But then - nothing

Th "click of sorts" could be the APS and PCB relay moving. It might also
be the click of the pilot gas valve which would happen 'simultaneously'
with those clicks.

Since there is no sparking the chances are that the spark lead is
shorted or the spark generator (PCB module) is kaput. You might be able to
get another clue by seeing if there is any smell of gas from the flue
terminal - this would show that the pilot gas valve has opened.

I think the correct sounds should be
Whirr (the fan) : 5-10 seconds (there are flow restrictors in the APS
tubes) : tick (APS switch)+click (PCB relay)+chonk(pilot gv) :
tick-tick-tick (HT sparker): silence a second or so (pilot lit but
flame sense making up it's mind) : CHONK (main GV) : hiss (gas flowing) :
woomph (gas ignites).

HTH

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is athttp://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQhttp://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQhttp://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs hehttp://www.makewrite.demon.co.uk/GasFittingStandards

Thanks

All the answers have been useful, but I vote this the most useful to
me who is not quite sure of what is going on.
From this I strongly suspect it is my PCB.
After the fan starts, I am hearing a sound more like a "chonk", which
suggest from the above the pilot valvle IS opening. But then no sparks
I also think I can smell a whiff of gas in the flue.

I think I have reached the limit of my knowledge, so I have a guy
coming this afternoon (name found in littlegreenbook.co.uk- wish me
luck)
I have told him I strongly the suspect the PCB, so he has agreed to
try and bring a re[placement with him...