Hi all,

A while ago some might remember me mentioning here that an elderly
neighbour we keep an eye on was finding heating on when she only
wanted hot water. I believe the diagnosis was the rubber ball in the
motorised valve was allowing water past into the CH cct when in the HW
position and I bought a new valve ready.

She was happy to just use immersion for HW so I thought we'd wait till
it was a little bit cooler in the loft and in general before doing the
job.

She mentioned to the Mrs earlier that it was starting to get a bit
cooler and so I just popped over to swap her back to the gas boiler
and re-set the timer to get things flowing again and whilst it looks
and sounds like it's trying to spark up, it's not managing to?

We have the water pump running (checked via the spindle cover), the
boiler fan, the igniter bit it looks like it might fire up a pilot
flame failure detector main burner but isn't getting the pilot, if
that's actually what happens. If it should light the main burner
directly from the igniter it's not doing that either. [1]

I can't smell any gas on the outside but I can feel reasonable
airflow.

Turn the main boiler knob to off, leave it a few seconds, turn it back
on again, and you hear the fan come on, then after a few seconds
delay, a fairly loud 'clunk' (gas valve?) and then the igniter starts
going but that's it? She has gas on the hob nearby.

Anyone had / got one and can remember the fire up sequence or can
offer any other thoughts please?

I've swapped her back to the immersion heater for tonight and can have
a closer look in the morning.

Cheers, T i m

[1] If you peer into the boiler though the spy hole and watch
carefully, every 3 or 4 sparks it looks like it is surrounded by a
tiny flame but as if it's blown out before it can build up?

In article ,
says...

Hi all,

A while ago some might remember me mentioning here that an elderly
neighbour we keep an eye on was finding heating on when she only
wanted hot water. I believe the diagnosis was the rubber ball in the
motorised valve was allowing water past into the CH cct when in the HW
position and I bought a new valve ready.

She was happy to just use immersion for HW so I thought we'd wait till
it was a little bit cooler in the loft and in general before doing the
job.

She mentioned to the Mrs earlier that it was starting to get a bit
cooler and so I just popped over to swap her back to the gas boiler
and re-set the timer to get things flowing again and whilst it looks
and sounds like it's trying to spark up, it's not managing to?

We have the water pump running (checked via the spindle cover), the
boiler fan, the igniter bit it looks like it might fire up a pilot
flame failure detector main burner but isn't getting the pilot, if
that's actually what happens. If it should light the main burner
directly from the igniter it's not doing that either. [1]

I can't smell any gas on the outside but I can feel reasonable
airflow.

Turn the main boiler knob to off, leave it a few seconds, turn it back
on again, and you hear the fan come on, then after a few seconds
delay, a fairly loud 'clunk' (gas valve?) and then the igniter starts
going but that's it? She has gas on the hob nearby.

Anyone had / got one and can remember the fire up sequence or can
offer any other thoughts please?

I've swapped her back to the immersion heater for tonight and can have
a closer look in the morning.

Cheers, T i m

[1] If you peer into the boiler though the spy hole and watch
carefully, every 3 or 4 sparks it looks like it is surrounded by a
tiny flame but as if it's blown out before it can build up?

Mine has exhibited these symptoms. Here's what I do to mine.
Isolate from electricity.
Pull off the thermostat knob. Remove a 'rubber' bung to reveal a screw
which holds on the control gear front cover. Remove the screw (mine is
captive)and the cover.
There is a clear plastic tube which passes through the steel backplate
close to the spark generator black box. It goes into a pressure switch
(a disk about 75mm dia). Where it passes through the backplate, the
plastic tube is jointed by what looks like a bit of brass tubing. But
this is a restrictor, with a very tiny hole in it. Pull the clear
plastic tubes off it and blow it out, or carefully probe with a fine
needle. Job done, I do it routinely about every 5 years.
You can test if the boiler starts by turning on the electricity, there
will be live terminals exposed, and sucking on the tube that goes to the
pressure switch. Re-assemble.
Hope this fixes it.

--
Take the dog out to email me

On Wed, 9 Oct 2019 21:50:12 +0100, Mike
wrote:

snip

[1] If you peer into the boiler though the spy hole and watch
carefully, every 3 or 4 sparks it looks like it is surrounded by a
tiny flame but as if it's blown out before it can build up?

Mine has exhibited these symptoms. Here's what I do to mine.
Isolate from electricity.
Pull off the thermostat knob. Remove a 'rubber' bung to reveal a screw
which holds on the control gear front cover. Remove the screw (mine is
captive)and the cover.

I have been in there a while back when fitting a replacement
controller PCB so that sounds familiar. ;-)

There is a clear plastic tube which passes through the steel backplate
close to the spark generator black box. It goes into a pressure switch
(a disk about 75mm dia).

Sounds familiar.

Where it passes through the backplate, the
plastic tube is jointed by what looks like a bit of brass tubing. But
this is a restrictor, with a very tiny hole in it. Pull the clear
plastic tubes off it and blow it out, or carefully probe with a fine
needle.

I think I may have a 'pricker' somewhere but she might also have a
good range of needles if I can't find it.

Job done, I do it routinely about every 5 years.

Fingers crossed then. ;-)

You can test if the boiler starts by turning on the electricity, there
will be live terminals exposed, and sucking on the tube that goes to the
pressure switch.

Understood.

Re-assemble.

Reverse of ...

Hope this fixes it.

Me too.

So, is it simply the fact that something doesn't think the fan is
running and pulling a sufficient vacuum on that side of the boiler to
turn on the main gas valve?

Cheers, T i m

On 09/10/2019 20:00, T i m wrote:
Hi all,

A while ago some might remember me mentioning here that an elderly
neighbour we keep an eye on was finding heating on when she only
wanted hot water. I believe the diagnosis was the rubber ball in the
motorised valve was allowing water past into the CH cct when in the HW
position and I bought a new valve ready.

She was happy to just use immersion for HW so I thought we'd wait till
it was a little bit cooler in the loft and in general before doing the
job.

She mentioned to the Mrs earlier that it was starting to get a bit
cooler and so I just popped over to swap her back to the gas boiler
and re-set the timer to get things flowing again and whilst it looks
and sounds like it's trying to spark up, it's not managing to?

We have the water pump running (checked via the spindle cover), the
boiler fan, the igniter bit it looks like it might fire up a pilot
flame failure detector main burner but isn't getting the pilot, if
that's actually what happens. If it should light the main burner
directly from the igniter it's not doing that either. [1]

I can't smell any gas on the outside but I can feel reasonable
airflow.

Turn the main boiler knob to off, leave it a few seconds, turn it back
on again, and you hear the fan come on, then after a few seconds
delay, a fairly loud 'clunk' (gas valve?) and then the igniter starts
going but that's it? She has gas on the hob nearby.

Anyone had / got one and can remember the fire up sequence or can
offer any other thoughts please?

I've swapped her back to the immersion heater for tonight and can have
a closer look in the morning.

Cheers, T i m

[1] If you peer into the boiler though the spy hole and watch
carefully, every 3 or 4 sparks it looks like it is surrounded by a
tiny flame but as if it's blown out before it can build up?


Going off at a tangent...
Beware of any activity which requires removing the case.

https://www.gassaferegister.co.uk/me...ance-cases.pdf

"... there is a risk that products of combustion may escape into the
rooms pace... ... A list of these types of appliances is contained in
Appendix 1"

Appendix 1 has a number of Potterton Netaheat Electronic products...

On Thu, 10 Oct 2019 15:31:49 +0100, John Kenyon
wrote:
snip

[1] If you peer into the boiler though the spy hole and watch
carefully, every 3 or 4 sparks it looks like it is surrounded by a
tiny flame but as if it's blown out before it can build up?


Going off at a tangent...

Please do. ;-)

Beware of any activity which requires removing the case.

https://www.gassaferegister.co.uk/me...ance-cases.pdf

Handy, thanks.

"... there is a risk that products of combustion may escape into the
rooms pace... ... A list of these types of appliances is contained in
Appendix 1"

Appendix 1 has a number of Potterton Netaheat Electronic products...


Noted (thanks).

Everything I've done on it so far is outside of the sealed case so
that's ok.

I checked the restrictor mentioned by Mike elsewhere and whilst I
can't say it was blocked, even after being pricked out and clear when
held up to the light, it was still quite restrictive to being blown
though (but on a par for the size of the hole).

Lightly sucking on the pipe caused the microswitch to 'click' so I put
the hoses back on and it did then fire up (see below).

I seemed to go though the same sequence (sat their sparking for maybe
30 seconds) but then fired up. I'm not sure if there was actually a
partial blockage in the pressure detector system or that I didn't
leave it long enough previously or just coincidence / something else
but it now seems to fire up ok, albeit after what seems like quite a
while trying.

As an aside, the front of the case seems to get quite hot (you can't
quite hold your hand on it), and smells a bit hot. maybe because it's
not been on for a few months or because it was working quite hard
bringing everything up to temp?

Anyway, whilst checking stuff out I noticed that the motorised valve
wasn't returning (by spring) to the un-powered position, even when the
head was removed, but would if you gave the motor gear a nudge?

Considering how old it all must be, maybe a complete new MV head
(V4073A1039) might be in order to go with the replacement valve?

Cheers, T i m

On 10/10/2019 16:02, T i m wrote:
On Thu, 10 Oct 2019 15:31:49 +0100, John Kenyon
wrote:
snip

[1] If you peer into the boiler though the spy hole and watch
carefully, every 3 or 4 sparks it looks like it is surrounded by a
tiny flame but as if it's blown out before it can build up?


Going off at a tangent...

Please do. ;-)

Beware of any activity which requires removing the case.

https://www.gassaferegister.co.uk/me...ance-cases.pdf

Handy, thanks.

"... there is a risk that products of combustion may escape into the
rooms pace... ... A list of these types of appliances is contained in
Appendix 1"

Appendix 1 has a number of Potterton Netaheat Electronic products...


Noted (thanks).

Everything I've done on it so far is outside of the sealed case so
that's ok.

I checked the restrictor mentioned by Mike elsewhere and whilst I
can't say it was blocked, even after being pricked out and clear when
held up to the light, it was still quite restrictive to being blown
though (but on a par for the size of the hole).

Lightly sucking on the pipe caused the microswitch to 'click' so I put
the hoses back on and it did then fire up (see below).

I seemed to go though the same sequence (sat their sparking for maybe
30 seconds) but then fired up. I'm not sure if there was actually a
partial blockage in the pressure detector system or that I didn't
leave it long enough previously or just coincidence / something else
but it now seems to fire up ok, albeit after what seems like quite a
while trying.

As an aside, the front of the case seems to get quite hot (you can't
quite hold your hand on it), and smells a bit hot. maybe because it's
not been on for a few months or because it was working quite hard
bringing everything up to temp?

Anyway, whilst checking stuff out I noticed that the motorised valve
wasn't returning (by spring) to the un-powered position, even when the
head was removed, but would if you gave the motor gear a nudge?

Considering how old it all must be, maybe a complete new MV head
(V4073A1039) might be in order to go with the replacement valve?

Cheers, T i m


I've just replaced a Netaheat Electronic 16/22 and have a fully working
electronics board which I was just about to put on eBay.

From memory you would hear the fan start, then the clunk, the faintly
the clicking of the igniter spark, then the whooomph as the burners lit
and another clunk. Sometimes it could be a long time till it lit but
probably only 30secs or so. It just felt like forever. The case did get
hot when it had been on a long time but not too hot to touch but really
quite hot.

Mine was 31yrs old when I replaced it last month. Replacement WB
Greenstar is almost silent in comparison (outside flue is noisier than
the old one). Difference in performance with a system boiler and
pressurised system is night and day. The Netaheat had 2 replacement
boards in the time I've been here, last one was in 2011. Also it
wouldn't light once and it turned out there was water/condensation in
the gas pipes. Only issues in 19years of use driving a hot water tank
and 14 rads in Sunnny Scotland.

I wonder if the WB will last 31 years?

On Thu, 10 Oct 2019 17:48:23 +0100, mm0fmf wrote:

snip

As an aside, the front of the case seems to get quite hot (you can't
quite hold your hand on it), and smells a bit hot. maybe because it's
not been on for a few months or because it was working quite hard
bringing everything up to temp?

Anyway, whilst checking stuff out I noticed that the motorised valve
wasn't returning (by spring) to the un-powered position, even when the
head was removed, but would if you gave the motor gear a nudge?

Considering how old it all must be, maybe a complete new MV head
(V4073A1039) might be in order to go with the replacement valve?


I've just replaced a Netaheat Electronic 16/22 and have a fully working
electronics board which I was just about to put on eBay.

What do they go for OOI?

From memory you would hear the fan start, then the clunk, the faintly
the clicking of the igniter spark, then the whooomph as the burners lit
and another clunk.

Sounds familiar. ;-)

Sometimes it could be a long time till it lit but
probably only 30secs or so. It just felt like forever.

Thanks and it does eh.

The case did get
hot when it had been on a long time but not too hot to touch but really
quite hot.

This one seems to get particularly hot on the lower half at the front,
but knowing where the burners are that probably makes sense.

Mine was 31yrs old when I replaced it last month. Replacement WB
Greenstar is almost silent in comparison (outside flue is noisier than
the old one). Difference in performance with a system boiler and
pressurised system is night and day. The Netaheat had 2 replacement
boards in the time I've been here, last one was in 2011.

I think I have repaired one for her (dryjoint) and then a couple of
years later, replaced it with a second hand one.

Also it
wouldn't light once and it turned out there was water/condensation in
the gas pipes.

Oh?

Only issues in 19years of use driving a hot water tank
and 14 rads in Sunnny Scotland.

I wonder if the WB will last 31 years?

And that of course is the question around the 'bigger picture'.

If the old boiler was not particularly efficient but cost little in
the way of replacement components and people driving miles in diesel
vans to repair it, I wonder how that might compare carbon footprint
wise with something supposedly 'greener' but possibly more complex and
so less reliable?

Thanks for the feedback. ;-)

Cheers, T i m

On Thu, 10 Oct 2019 16:02:21 +0100, T i m wrote:

snip
I checked the restrictor mentioned by Mike elsewhere and whilst I can't
say it was blocked, even after being pricked out and clear when held up
to the light, it was still quite restrictive to being blown though (but
on a par for the size of the hole).
snip
Cheers, T i m

Just reminded me that with our old (ancient) boiler everything was fine
apart from the thermocouple needing replacing now and then, and the pilot
light gas jet getting blocked now and then.
As far as I can tell there was a bit of dust/dirt in the gas feed which
occasionally blocked the pilot light.
A quick clean - poke and blow - and all was well for another year or so.

So there could just be a little dust in the piping which blocks the pilot
light now and then.


Cheers



Dave R

--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On 11/10/2019 09:55, T i m wrote:
What do they go for OOI?

On eBay for secondhand as seen inc P&p, less than £50. Secondhand but
with guarantee inc p&p, I've seen upto £125 asked for them.

I believe the gas valves are no longer available new. There may well be
plenty of used spares about however. I'm not sure what the legal and/or
of safety implications are in fitting secondhand gas valves. Fans and
seals etc. are available still.

In my case I'd put off replacing it for far too long and hearing of the
gas valve situation, I finally cracked my wallet open!

I've just replaced the valve body on the motorised valve serving the upstairs zone in my house. It was extremely stiff to turn even with the head off and a pair of pliers on the shaft.
It wasn't worth the aggravation of trying to remove the spindle to investigate and possibly clean and lubricate with a risk the shaft seal would leak afterwards.
Fortunately I had installed gate valves either side in the pipework when I first put the system in so it was a few minutes work and no drain down required.

On Wed, 09 Oct 2019 20:00:01 +0100, T i m wrote:

Hi all,

A while ago some might remember me mentioning here that an elderly
neighbour we keep an eye on was finding heating on when she only
wanted hot water. I believe the diagnosis was the rubber ball in the
motorised valve was allowing water past into the CH cct when in the HW
position and I bought a new valve ready.

She was happy to just use immersion for HW so I thought we'd wait till
it was a little bit cooler in the loft and in general before doing the
job.

She mentioned to the Mrs earlier that it was starting to get a bit
cooler and so I just popped over to swap her back to the gas boiler
and re-set the timer to get things flowing again and whilst it looks
and sounds like it's trying to spark up, it's not managing to?

We have the water pump running (checked via the spindle cover), the
boiler fan, the igniter bit it looks like it might fire up a pilot
flame failure detector main burner but isn't getting the pilot, if
that's actually what happens. If it should light the main burner
directly from the igniter it's not doing that either. [1]

I can't smell any gas on the outside but I can feel reasonable
airflow.

Turn the main boiler knob to off, leave it a few seconds, turn it back
on again, and you hear the fan come on, then after a few seconds
delay, a fairly loud 'clunk' (gas valve?) and then the igniter starts
going but that's it? She has gas on the hob nearby.

Anyone had / got one and can remember the fire up sequence or can
offer any other thoughts please?

I've swapped her back to the immersion heater for tonight and can have
a closer look in the morning.

Cheers, T i m

[1] If you peer into the boiler though the spy hole and watch
carefully, every 3 or 4 sparks it looks like it is surrounded by a
tiny flame but as if it's blown out before it can build up?


Update:

The slowness to fire up still persists but it may be that's just how
they are. However, whilst it takes a while (10's of seconds) it does
seem to fire up reliably.

A secondary issue was that it didn't seem to come on when in 'Heating'
and that was as determined by some deeper fault finding with the DMM
down to both of the micro switches in the motorised valve being faulty
(O/c, one on the n/c and the other on the n/o when actioned).

I replaced the head earlier and tested it on HW, CH and HW+CH and it
seemed to respond as predicted (watching the valve actuator with the
cover off).

There is the possibility that a pre-existing fault remains and that
was leakage of water past the valve when in HW only, causing the CH to
come on when not called. I need to check for that when the system is
cold and have a new valve top plate that I can change if required.

Cheers, T i m

p.s. Just for the S&G's, I may try to locate replacement micro
switches, replace them on the old head and then see if it behaves as
it should (on the bench ... I can make a suitable stop with some mole
grips on the spindle).