Hello...hopefully someone may be able to diagnose this boiler problem:

I have a Potterton Netaheat 16/22- probably about 15 years old. Its
been running fine for hot water over the summer, and for the last 2
weeks of central heating as well, but a few days ago it developed this
problem:
-Turn heating and/or hot water on at the timer
-Valves (S-type layout?- 2* 2-way valves) and pump appear to work OK
-Pilot, then main flame lights and everything runs OK for 2-5 minutes
-Flame goes out and there is a continuous loud clicking sound coming
from the boiler. The pilot re-lights after the first click, but fades
and eventualy goes out as the clicking continues. The main flame never
comes back.
-The clicking carries on until I switch off the heating or water timer
control (after about 30 seconds as I don't want anything to blow up!)
-Waiting a few minutes and then switching the heating or water on
again results in a repeat of the same process.

Is this likely to be a repair I could do myself, or should I just get
a new boiler?

Many thanks,
Dave

"Dave Ramage" wrote in message
om...
Hello...hopefully someone may be able to diagnose this boiler problem:

I have a Potterton Netaheat 16/22- probably about 15 years old. Its
been running fine for hot water over the summer, and for the last 2
weeks of central heating as well, but a few days ago it developed this
problem:
-Turn heating and/or hot water on at the timer
-Valves (S-type layout?- 2* 2-way valves) and pump appear to work OK
-Pilot, then main flame lights and everything runs OK for 2-5 minutes
-Flame goes out and there is a continuous loud clicking sound coming
from the boiler. The pilot re-lights after the first click, but fades
and eventualy goes out as the clicking continues. The main flame never
comes back.
-The clicking carries on until I switch off the heating or water timer
control (after about 30 seconds as I don't want anything to blow up!)
-Waiting a few minutes and then switching the heating or water on
again results in a repeat of the same process.

Is this likely to be a repair I could do myself, or should I just get
a new boiler?

One version of the neataheat had a plug in relay. It sounds as if this has
failed. have a look it is quite large. Check it out. Some time you can
see it arcing. If it has failed go to Maplin and buy one the same. The
makers charge more for a standard common relay you can buy anywhere..


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"Dave Ramage" wrote in message
om...
Hello...hopefully someone may be able to diagnose this boiler problem:

I have a Potterton Netaheat 16/22- probably about 15 years old. Its
been running fine for hot water over the summer, and for the last 2
weeks of central heating as well, but a few days ago it developed this
problem:
-Turn heating and/or hot water on at the timer
-Valves (S-type layout?- 2* 2-way valves) and pump appear to work OK
-Pilot, then main flame lights and everything runs OK for 2-5 minutes
-Flame goes out and there is a continuous loud clicking sound coming
from the boiler. The pilot re-lights after the first click, but fades
and eventualy goes out as the clicking continues. The main flame never
comes back.
-The clicking carries on until I switch off the heating or water timer
control (after about 30 seconds as I don't want anything to blow up!)
-Waiting a few minutes and then switching the heating or water on
again results in a repeat of the same process.

Is this likely to be a repair I could do myself, or should I just get
a new boiler?

Many thanks,
Dave

Watch out for line wrap:

http://www.fmb.org.uk/publications/m...nuary01/4c.asp

"BigWallop" wrote in message
...

"Dave Ramage" wrote in message
om...
Hello...hopefully someone may be able to diagnose this boiler problem:

I have a Potterton Netaheat 16/22- probably about 15 years old. Its
been running fine for hot water over the summer, and for the last 2
weeks of central heating as well, but a few days ago it developed this
problem:
-Turn heating and/or hot water on at the timer
-Valves (S-type layout?- 2* 2-way valves) and pump appear to work OK
-Pilot, then main flame lights and everything runs OK for 2-5 minutes
-Flame goes out and there is a continuous loud clicking sound coming
from the boiler. The pilot re-lights after the first click, but fades
and eventualy goes out as the clicking continues. The main flame never
comes back.
-The clicking carries on until I switch off the heating or water timer
control (after about 30 seconds as I don't want anything to blow up!)
-Waiting a few minutes and then switching the heating or water on
again results in a repeat of the same process.

Is this likely to be a repair I could do myself, or should I just get
a new boiler?

Many thanks,
Dave

Watch out for line wrap:

http://www.fmb.org.uk/publications/m...nuary01/4c.asp



And this:

http://www.healthandsafety.co.uk/E19800.html

In message , IMM
writes

One version of the neataheat had a plug in relay. It sounds as if this has
failed. have a look it is quite large. Check it out. Some time you can
see it arcing. If it has failed go to Maplin and buy one the same. The
makers charge more for a standard common relay you can buy anywhere..


Yes, this version - the other version is the Netaheat electronic John

If the main gas valve is opening and staying on "reliably" for a couple
of minutes, then I doubt it's the relay. If the relay contacts were on
their way out, I would expect it to either work intermittently or just
fail. It sounds to me more like the overheat stat opening and shutting
down the boiler.

I don't have any experience regarding scaling up of cast iron heat
exchangers, but I would think it is likely that, for some reason, the
heat delivered to the heat exchanger is not being dissipated and so the
boiler overheat stat is shutting the boiler down
--
geoff

In message , BigWallop
writes

"Dave Ramage" wrote in message
. com...
Hello...hopefully someone may be able to diagnose this boiler problem:

I have a Potterton Netaheat 16/22- probably about 15 years old. Its
been running fine for hot water over the summer, and for the last 2
weeks of central heating as well, but a few days ago it developed this
problem:
-Turn heating and/or hot water on at the timer
-Valves (S-type layout?- 2* 2-way valves) and pump appear to work OK
-Pilot, then main flame lights and everything runs OK for 2-5 minutes
-Flame goes out and there is a continuous loud clicking sound coming
from the boiler. The pilot re-lights after the first click, but fades
and eventualy goes out as the clicking continues. The main flame never
comes back.
-The clicking carries on until I switch off the heating or water timer
control (after about 30 seconds as I don't want anything to blow up!)
-Waiting a few minutes and then switching the heating or water on
again results in a repeat of the same process.

Is this likely to be a repair I could do myself, or should I just get
a new boiler?

Many thanks,
Dave

Watch out for line wrap:

http://www.fmb.org.uk/publications/m...nuary01/4c.asp


But wouldn't this cause the boiler to blow the flame out immediately
--
geoff

One version of the neataheat had a plug in relay. It sounds as if this has
failed. have a look it is quite large. Check it out. Some time you can
see it arcing. If it has failed go to Maplin and buy one the same. The
makers charge more for a standard common relay you can buy anywhere..


IMM,

Thanks for this- I'll take a look tonight.

Dave

geoff, BW,

Thanks for this info....another reason to consider a replacement
rather than patch it up. It also seems that the seals are asbestos
according to other posts.

This could also explain that when I tested the boiler briefly with the
cover off to see if the fan was working there was a fair bit of flame
emitted around the bottom of the fire box when it lit.

geoff wrote in message ...
In message , BigWallop
writes

"Dave Ramage" wrote in message
. com...
Hello...hopefully someone may be able to diagnose this boiler problem:

I have a Potterton Netaheat 16/22- probably about 15 years old. Its
been running fine for hot water over the summer, and for the last 2
weeks of central heating as well, but a few days ago it developed this
problem:
-Turn heating and/or hot water on at the timer
-Valves (S-type layout?- 2* 2-way valves) and pump appear to work OK
-Pilot, then main flame lights and everything runs OK for 2-5 minutes
-Flame goes out and there is a continuous loud clicking sound coming
from the boiler. The pilot re-lights after the first click, but fades
and eventualy goes out as the clicking continues. The main flame never
comes back.
-The clicking carries on until I switch off the heating or water timer
control (after about 30 seconds as I don't want anything to blow up!)
-Waiting a few minutes and then switching the heating or water on
again results in a repeat of the same process.

Is this likely to be a repair I could do myself, or should I just get
a new boiler?

Many thanks,
Dave

Watch out for line wrap:

http://www.fmb.org.uk/publications/m...nuary01/4c.asp


But wouldn't this cause the boiler to blow the flame out immediately

Hi

I`ve got one of these boilers about the same age and if I remember correctly, I
think I had a similar problem around 10 years ago.

The fault was due to the flue extractor fan micro-switch failing meaning that
the boiler didn`t recognise that the fan was drawing out the exhaust fumes and
so it switched off.





Hello...hopefully someone may be able to diagnose this boiler problem:

I have a Potterton Netaheat 16/22- probably about 15 years old. Its
been running fine for hot water over the summer, and for the last 2
weeks of central heating as well, but a few days ago it developed this
problem:
-Turn heating and/or hot water on at the timer
-Valves (S-type layout?- 2* 2-way valves) and pump appear to work OK
-Pilot, then main flame lights and everything runs OK for 2-5 minutes
-Flame goes out and there is a continuous loud clicking sound coming
from the boiler. The pilot re-lights after the first click, but fades
and eventualy goes out as the clicking continues. The main flame never
comes back.
-The clicking carries on until I switch off the heating or water timer
control (after about 30 seconds as I don't want anything to blow up!)
-Waiting a few minutes and then switching the heating or water on
again results in a repeat of the same process.

Is this likely to be a repair I could do myself, or should I just get
a new boiler?

Many thanks,
Dave

"Dave Ramage" wrote in message
om...
geoff, BW,

Thanks for this info....another reason to consider a replacement
rather than patch it up. It also seems that the seals are asbestos
according to other posts.

Yes they are.

This could also explain that when I tested the boiler briefly with the
cover off to see if the fan was working there was a fair bit of flame
emitted around the bottom of the fire box when it lit.

The Neataheat was the first pilotless ignition boiler made. It was quite
advanced for its time, well by British standards. It is a "very" good and
reliable boiler, although the first models out had some problems which near
killed off the boiler, which were soon rectified. But times move on. It is
cast iron, even in the mid 1970s it was inefficient, and very inefficient by
modern condensing standards. By installing a good condensing boiler you
will drop your gas heating bills approx 35-40%.

Figures like that make you sit up and look. So if this is a pretty
expensive job to fix (probably £100 or more) then a new condensing boiler is
well worth considering. Taking into account the money saved on repair and
then on gas saved, payback will be quite soon.







---
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"Smithtv" wrote in message
...
Hi

I`ve got one of these boilers about the same age and if I remember
correctly, I
think I had a similar problem around 10 years ago.

The fault was due to the flue extractor fan micro-switch failing meaning
that
the boiler didn`t recognise that the fan was drawing out the exhaust fumes
and
so it switched off.

If it was my boiler, I would replace the exhaust gas differential switch and
the relay. They are both getting on.


---
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Checked by AVG anti-virus system (http://www.grisoft.com).
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Dave Ramage wrote:


Thanks for this info....another reason to consider a replacement
rather than patch it up. It also seems that the seals are asbestos
according to other posts.

This could also explain that when I tested the boiler briefly with the
cover off to see if the fan was working there was a fair bit of flame
emitted around the bottom of the fire box when it lit.

I've had one of these boilers for 23 years and it still going strong.
AFAIK you can't run the boiler without the cover on.
I too had a similar problem some years ago and it turned out to be problem
with the interlock from the fan. In my case it was a flexy tube to the
diaphram switch.
The seals are asbestos rope but that shouldn't be problem unless you remove
or dismantle the boiler.

geoff wrote:

In message , IMM
writes

One version of the neataheat had a plug in relay. It sounds as if this has
failed. have a look it is quite large. Check it out. Some time you can
see it arcing. If it has failed go to Maplin and buy one the same. The
makers charge more for a standard common relay you can buy anywhere..


Yes, this version - the other version is the Netaheat electronic John

If the main gas valve is opening and staying on "reliably" for a couple
of minutes, then I doubt it's the relay. If the relay contacts were on
their way out, I would expect it to either work intermittently or just
fail. It sounds to me more like the overheat stat opening and shutting
down the boiler.

IIRC the O/H stat has to be manually reset?

I agree the relay anbd gas valve are probably fine.
My guess: it's a combination of dirt on the air flow proving tubes
and/or poor contact on the switch itself. I'm guessing that as the flue
gasses warm up the air flow proving becomes marginal and this leads to a
poor contact in the diaphragm switch which makes the clicking of the
relay and the pilot gas valve.
The main gas valve 'click' has very substantial hysterisis ans is
unlikely to "thrash".

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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

IMM wrote:
=

"Dave Ramage" wrote in message
om...
geoff, BW,

Thanks for this info....another reason to consider a replacement
rather than patch it up. It also seems that the seals are asbestos
according to other posts.
=

Yes they are.
=

This could also explain that when I tested the boiler briefly with th=
e
cover off to see if the fan was working there was a fair bit of flame=

emitted around the bottom of the fire box when it lit.
=

The Neataheat was the first pilotless ignition boiler made. It was quit=
e
advanced for its time, well by British standards. It is a "very" good =
and
reliable boiler, although the first models out had some problems which =
near
killed off the boiler, which were soon rectified. But times move on. =
It is
cast iron, even in the mid 1970s it was inefficient, and very inefficie=
nt by
modern condensing standards. By installing a good condensing boiler yo=
u
will drop your gas heating bills approx 35-40%.
=

Figures like that make you sit up and look. So if this is a pretty
expensive job to fix (probably =A3100 or more) then a new condensing bo=
iler is
well worth considering. Taking into account the money saved on repair a=
nd
then on gas saved, payback will be quite soon.
=

Whilst I expect a saving of upto 35% on the worst case older boilers to
a modern condensing boiler you would be hard pressed to get such a
saving. My combustion analyser can show efficiency (or rather
inefficiency due to exhaust gas losses - which is not _quite_ the same
thing). I have seen over 90% on a Keston flue; less than 70% on an Ideal
Concord; and over 80% of a Neatheat. Furthermore those fgures are during
operation, the heat losses when the boiler flame is out but the pump is
on can only make my argument stronger. =



-- =

Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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

In message , IMM
writes

"Dave Ramage" wrote in message
. com...
geoff, BW,

Thanks for this info....another reason to consider a replacement
rather than patch it up. It also seems that the seals are asbestos
according to other posts.

Yes they are.

This could also explain that when I tested the boiler briefly with the
cover off to see if the fan was working there was a fair bit of flame
emitted around the bottom of the fire box when it lit.

The Neataheat was the first pilotless ignition boiler made. It was quite
advanced for its time, well by British standards. It is a "very" good and
reliable boiler, although the first models out had some problems which near
killed off the boiler, which were soon rectified. But times move on. It is
cast iron, even in the mid 1970s it was inefficient, and very inefficient by
modern condensing standards. By installing a good condensing boiler you
will drop your gas heating bills approx 35-40%.

Figures like that make you sit up and look. So if this is a pretty
expensive job to fix (probably £100 or more) then a new condensing boiler is
well worth considering. Taking into account the money saved on repair and
then on gas saved, payback will be quite soon.


Until, that is, something goes wrong ...
--
geoff

In message , Smithtv
writes
Hi

I`ve got one of these boilers about the same age and if I remember correctly, I
think I had a similar problem around 10 years ago.

The fault was due to the flue extractor fan micro-switch failing meaning that
the boiler didn`t recognise that the fan was drawing out the exhaust fumes and
so it switched off.

Ah, but unless the air pressure switch is working properly, the pilot
and spark won't be energised, so that can't be the case here

--
geoff

(Dave Ramage) wrote in message . com...
Hello...hopefully someone may be able to diagnose this boiler problem:
and pump appear to work OK

This sounds like the boiler going out on High Temp, usually caused by
the pump failing.
Remove the large silver screw in the centre of the pump and insert a
screwdriver, gently, you should feel the pump rotating. A new one is
£40 + fitting


- Is this likely to be a repair I could do myself, or should I just get
a new boiler?

Many thanks,
Dave

On Mon, 13 Oct 2003 17:48:17 +0100, "BillR"
wrote:

Dave Ramage wrote:


Thanks for this info....another reason to consider a replacement
rather than patch it up. It also seems that the seals are asbestos
according to other posts.

This could also explain that when I tested the boiler briefly with the
cover off to see if the fan was working there was a fair bit of flame
emitted around the bottom of the fire box when it lit.

I've had one of these boilers for 23 years and it still going strong.
AFAIK you can't run the boiler without the cover on.
I too had a similar problem some years ago and it turned out to be problem
with the interlock from the fan. In my case it was a flexy tube to the
diaphram switch.
The seals are asbestos rope but that shouldn't be problem unless you remove
or dismantle the boiler.

My parents have had one for probably even longer, and they are only
thinking about replacing it now due to it being a little noisy. Has
been pretty reliable apart from one time that a loose screw was
holding a gas valve open, which caused a leak that then caused a small
explosion one morning. Was a very load bang, and the casing ended up
so deformed that it would not pressurise!

I also remember helping my father move it up into the loft of their
new extension - that boiler is seriously heavy.


--
Colin Swan

(bob) wrote in message om...
(Dave Ramage) wrote in message . com...
Hello...hopefully someone may be able to diagnose this boiler problem:
and pump appear to work OK

This sounds like the boiler going out on High Temp, usually caused by
the pump failing.
Remove the large silver screw in the centre of the pump and insert a
screwdriver, gently, you should feel the pump rotating. A new one is
£40 + fitting


Bob,

Thanks for the suggestion. Just checked this and the pump is turning
OK- there was a plastic hex head screw in the centre that unscrews and
pops out a bit to allow manual turning. Got a heating engineer (?)
coming around this afternoon to quote so will see what happens...

Cheers,
Dave.

Thought I'd follow this up with the final solution!

After poking around with a multimeter for a while and not finding
anything obvious with the boiler stat or air pressure switch,
eventually bit the bullet and got a local boiler guy in to take a
look. He poked around with a multimeter for 10 minutes or so and
diagnosed the problem to be the PCB. Was initially suspitious as this
happens to be one of the more expensive components! (£90 or so), but
was at least quick to fit. Eventualy went for a reconditioned PCB at
£30 or so. Seems to have fixed the problem. £130 incl. seems small
price to pay for working CH at this time of year!

Many thanks for all the help- was worth a try doing it myself!

Cheers,
Dave.