My netaheat electronic boiler will switch on, piolot light, then full
flame for a few seconds then switches off. Any dieas what may be
wrong? It was really going well up until now.

thanks
Kordi

On Mon, 23 Jun 2008 01:42:35 -0700, kim.hayward wrote:

My netaheat electronic boiler will switch on, piolot light, then full
flame for a few seconds then switches off. Any dieas what may be
wrong? It was really going well up until now.

pump not running or other blockage in system?
feed pipe from header tank to system blocked (scaled up)?

http://wiki.diyfaq.org.uk/index.php?...Heating_Repair

--
John Stumbles

My karma ran over my dogma

On Mon, 23 Jun 2008 01:42:35 -0700, kim.hayward wrote:

My netaheat electronic boiler will switch on, piolot light, then full
flame for a few seconds then switches off. Any dieas what may be wrong?
It was really going well up until now.


Does it do this repeatedly over and over again or just once in a while
(with no flames at all in between) say every 20-60 minutes give or take ?
Probably fires for about 60s initially.

1) If once in a while then probably there is no primary circulation (pump
problem, blockage etc., lack of water! due to stuck float valve in loft)

Otherwise
2) Flame detection problem. The flames light but the electronics/
electrode are failing to register the flames so the control unit shuts
down. Then (because it's a fairly simple control unit) starts over
again. Problems include: crud on electrode, broken wire, electrode not
in flames, faulty electronics).
Note that the pilot flame is detected initially but the same electrode
and circuit fail to detect/confirm the main event.

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

In message , Ed Sirett
writes
On Mon, 23 Jun 2008 01:42:35 -0700, kim.hayward wrote:

My netaheat electronic boiler will switch on, piolot light, then full
flame for a few seconds then switches off. Any dieas what may be wrong?
It was really going well up until now.


Does it do this repeatedly over and over again or just once in a while
(with no flames at all in between) say every 20-60 minutes give or take ?
Probably fires for about 60s initially.

1) If once in a while then probably there is no primary circulation (pump
problem, blockage etc., lack of water! due to stuck float valve in loft)

Otherwise
2) Flame detection problem. The flames light but the electronics/
electrode are failing to register the flames so the control unit shuts
down. Then (because it's a fairly simple control unit) starts over
again. Problems include: crud on electrode, broken wire, electrode not
in flames, faulty electronics).
Note that the pilot flame is detected initially but the same electrode
and circuit fail to detect/confirm the main event.


Additional info for Ed, John, etc ...

The netaheat pcb is a bit quirky in that the pilot valve falls back from
pull in voltage to holding voltage via a relay

If there is a failure in this area, it could cause the problem


--
geoff

On Mon, 23 Jun 2008 21:57:06 +0100, geoff wrote:

In message , Ed Sirett
writes
On Mon, 23 Jun 2008 01:42:35 -0700, kim.hayward wrote:

My netaheat electronic boiler will switch on, piolot light, then full
flame for a few seconds then switches off. Any dieas what may be
wrong?
It was really going well up until now.


Does it do this repeatedly over and over again or just once in a while
(with no flames at all in between) say every 20-60 minutes give or take
? Probably fires for about 60s initially.

1) If once in a while then probably there is no primary circulation
(pump problem, blockage etc., lack of water! due to stuck float valve in
loft)

Otherwise
2) Flame detection problem. The flames light but the electronics/
electrode are failing to register the flames so the control unit shuts
down. Then (because it's a fairly simple control unit) starts over
again. Problems include: crud on electrode, broken wire, electrode not
in flames, faulty electronics).
Note that the pilot flame is detected initially but the same electrode
and circuit fail to detect/confirm the main event.


Additional info for Ed, John, etc ...

The netaheat pcb is a bit quirky in that the pilot valve falls back from
pull in voltage to holding voltage via a relay

If there is a failure in this area, it could cause the problem

Thanks, I wasn't aware of that trick. A diagnostic for that would be that
you'd here the pilot valve click off (due to the relay problem) then a
moment later the main valve would close due to the flame sense failure.

Does the main valve also have this "feature" of diffeent pull-in and
holding voltages?


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

In message , Ed Sirett
writes
On Mon, 23 Jun 2008 21:57:06 +0100, geoff wrote:

In message , Ed Sirett
writes
On Mon, 23 Jun 2008 01:42:35 -0700, kim.hayward wrote:

My netaheat electronic boiler will switch on, piolot light, then full
flame for a few seconds then switches off. Any dieas what may be
wrong?
It was really going well up until now.


Does it do this repeatedly over and over again or just once in a while
(with no flames at all in between) say every 20-60 minutes give or take
? Probably fires for about 60s initially.

1) If once in a while then probably there is no primary circulation
(pump problem, blockage etc., lack of water! due to stuck float valve in
loft)

Otherwise
2) Flame detection problem. The flames light but the electronics/
electrode are failing to register the flames so the control unit shuts
down. Then (because it's a fairly simple control unit) starts over
again. Problems include: crud on electrode, broken wire, electrode not
in flames, faulty electronics).
Note that the pilot flame is detected initially but the same electrode
and circuit fail to detect/confirm the main event.


Additional info for Ed, John, etc ...

The netaheat pcb is a bit quirky in that the pilot valve falls back from
pull in voltage to holding voltage via a relay

If there is a failure in this area, it could cause the problem

Thanks, I wasn't aware of that trick. A diagnostic for that would be that
you'd here the pilot valve click off (due to the relay problem) then a
moment later the main valve would close due to the flame sense failure.

Does the main valve also have this "feature" of diffeent pull-in and
holding voltages?

No, just the pilot

It's weird - not seen it anywhere else

That's what the big green power resistor is for, it's the voltage
dropper

--
geoff