I have a boiler that is cutting out. I don't know the model number, but it
has a "ravenheat" logo on it.

It is a gas boiler, I have the system pressurised to 1 bar, and it does
instant hot water. All the radiators have TRVs on them (yes, all), and
there is no room stat. (Ex council house, cheap council installation)

I have tried putting one radiator valve on full to see if it is overheating
and tripping out, but it still does. I have also tried altering the water
temperature (both tap and rads), with no effect.

After the CH has been on for a while, I notice the rads are cold, and the
boiler fan is going, but the flame is not burning. Lowering the rad
thermostat on the boiler until it clicks, then putting it back resets it,
and it fires up fine. Also, clicking the time clock off and on does the
trick.

Any ideas?

Thanks

Bob

In an earlier contribution to this discussion,
Bob Smith wrote:

I have a boiler that is cutting out. I don't know the model number,
but it has a "ravenheat" logo on it.

It is a gas boiler, I have the system pressurised to 1 bar, and it
does instant hot water. All the radiators have TRVs on them (yes,
all), and there is no room stat. (Ex council house, cheap council
installation)

I have tried putting one radiator valve on full to see if it is
overheating and tripping out, but it still does. I have also tried
altering the water temperature (both tap and rads), with no effect.

After the CH has been on for a while, I notice the rads are cold, and
the boiler fan is going, but the flame is not burning. Lowering the
rad thermostat on the boiler until it clicks, then putting it back
resets it, and it fires up fine. Also, clicking the time clock off
and on does the trick.

Any ideas?

Thanks

Bob


Well one thing's clear - the boiler's overheat stat is tripping - and has to
be manually reset before the boiler will fire again.

What isn't so clear is *why*. This could be due to any of several causes,
which need investigating, including:
* faulty overheat stat (possibly the prime suspect)
* insufficient circulation to carry the residual heat away after the main
stat turns the flame off (This could certainly be the case if *all* the TRVs
are closed and *may* be the case if only one TRV is open. There could also
be an intermittent pump problem - but that doesn't sound too likely.) [If
circulation *is* the problem, I would expect turning down the boiler stat to
improve matters - since there's more leaway for the temperature to rise
before tripping the overheat stat].
* incorrectly wired pump (This is probably the least likely, and would only
really apply if the whole lot were turned on and off with a room stat - in
which case it must be wired to keep the pump running for a while after
turning the boiler off)

Do you have a means of measuring flow temperature. [If not, it may be a good
time to invest in an instant reading non-contact IR device from CPC for
£30 - I don't know how I ever managed without mine!] If you can check the
boiler outlet pipe temperature immediately after it trips, you can see
whether the temperature *is* excessive. If it's not, it points to the
overheat stat. If you suspect the overheat stat, try bridging it - but keep
a very close eye on the system while running bridged! If this cures it
without any side effects, fit a new overheat stat. If you get lots of
gurgling and banging, , turn it off a bit smartish! In this case, it really
*is* overheating and you need to look at some of the other possibilities.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
Bob Smith wrote:

I have a boiler that is cutting out. I don't know the model number,
but it has a "ravenheat" logo on it.

It is a gas boiler, I have the system pressurised to 1 bar, and it
does instant hot water. All the radiators have TRVs on them (yes,
all), and there is no room stat. (Ex council house, cheap council
installation)

I have tried putting one radiator valve on full to see if it is
overheating and tripping out, but it still does. I have also tried
altering the water temperature (both tap and rads), with no effect.

After the CH has been on for a while, I notice the rads are cold, and
the boiler fan is going, but the flame is not burning. Lowering the
rad thermostat on the boiler until it clicks, then putting it back
resets it, and it fires up fine. Also, clicking the time clock off
and on does the trick.

Any ideas?

Thanks

Bob


Well one thing's clear - the boiler's overheat stat is tripping - and has
to
be manually reset before the boiler will fire again.

What isn't so clear is *why*. This could be due to any of several causes,
which need investigating, including:
* faulty overheat stat (possibly the prime suspect)
* insufficient circulation to carry the residual heat away after the main
stat turns the flame off (This could certainly be the case if *all* the
TRVs
are closed and *may* be the case if only one TRV is open. There could also
be an intermittent pump problem - but that doesn't sound too likely.) [If
circulation *is* the problem, I would expect turning down the boiler stat
to
improve matters - since there's more leaway for the temperature to rise
before tripping the overheat stat].
* incorrectly wired pump (This is probably the least likely, and would onl
y
really apply if the whole lot were turned on and off with a room stat - in
which case it must be wired to keep the pump running for a while after
turning the boiler off)

Do you have a means of measuring flow temperature. [If not, it may be a
good
time to invest in an instant reading non-contact IR device from CPC for
£30 - I don't know how I ever managed without mine!] If you can check the
boiler outlet pipe temperature immediately after it trips, you can see
whether the temperature *is* excessive. If it's not, it points to the
overheat stat. If you suspect the overheat stat, try bridging it - but
keep
a very close eye on the system while running bridged! If this cures it
without any side effects, fit a new overheat stat. If you get lots of
gurgling and banging, , turn it off a bit smartish! In this case, it
really
*is* overheating and you need to look at some of the other possibilities.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!



Some useful ideas, thanks - I never get to it just after it has tripped to
take a temperature though.

The pump has a 3 minute overrun. If there *is* a (can't remember the name -
thingy in case all rads are off) would the boiler stop heating in time for
the small amount of water to not overheat?

If it has tripped out because of too much heat, would the act of turning
down the radiator temp knob until it clicks, then putting it back be enough
to reset it? (the boiler in my last house, you had to take the case off and
open a metal enclosure to get to the thermal cutout reset).

I will turn the temp down, and leave 2 rads on full to see if it cuts down
the frequency of tripouts.

Bob

In an earlier contribution to this discussion,
Bob Smith wrote:

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
Bob Smith wrote:

I have a boiler that is cutting out. I don't know the model
number, but it has a "ravenheat" logo on it.

It is a gas boiler, I have the system pressurised to 1 bar, and it
does instant hot water. All the radiators have TRVs on them (yes,
all), and there is no room stat. (Ex council house, cheap council
installation)

I have tried putting one radiator valve on full to see if it is
overheating and tripping out, but it still does. I have also tried
altering the water temperature (both tap and rads), with no effect.

After the CH has been on for a while, I notice the rads are cold,
and the boiler fan is going, but the flame is not burning.
Lowering the rad thermostat on the boiler until it clicks, then
putting it back resets it, and it fires up fine. Also, clicking
the time clock off and on does the trick.

Any ideas?

Thanks

Bob


Well one thing's clear - the boiler's overheat stat is tripping -
and has to be manually reset before the boiler will fire again.

What isn't so clear is *why*. This could be due to any of several
causes, which need investigating, including:
* faulty overheat stat (possibly the prime suspect)
* insufficient circulation to carry the residual heat away after the
main stat turns the flame off (This could certainly be the case if
*all* the TRVs are closed and *may* be the case if only one TRV is
open. There could also be an intermittent pump problem - but that
doesn't sound too likely.) [If circulation *is* the problem, I would
expect turning down the boiler stat to improve matters - since
there's more leaway for the temperature to rise before tripping the
overheat stat]. * incorrectly wired pump (This is probably the least
likely, and would onl y really apply if the whole lot were turned on
and off with a room stat - in which case it must be wired to keep
the pump running for a while after turning the boiler off)

Do you have a means of measuring flow temperature. [If not, it may
be a good time to invest in an instant reading non-contact IR device
from CPC for £30 - I don't know how I ever managed without mine!] If
you can check the boiler outlet pipe temperature immediately after
it trips, you can see whether the temperature *is* excessive. If
it's not, it points to the overheat stat. If you suspect the
overheat stat, try bridging it - but keep a very close eye on the
system while running bridged! If this cures it without any side
effects, fit a new overheat stat. If you get lots of gurgling and
banging, , turn it off a bit smartish! In this case, it really *is*
overheating and you need to look at some of the other possibilities.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!



Some useful ideas, thanks - I never get to it just after it has
tripped to take a temperature though.

You could try to induce it to misbehave though, by turning off the CH at the
programmer when the boiler is running at full chat. Verify that the pump
continues to run, and monitor the outlet temperature for a couple of
minutes.

The pump has a 3 minute overrun. If there *is* a (can't remember the
name - thingy in case all rads are off) would the boiler stop heating
in time for the small amount of water to not overheat?

You're probably referring to an automatic by-pass valve. If you had one -
which you probably don't - it would open if the pump were running but the
water had nowhere else to go because all the TRVs were closed. As long as
the pump kept going for a little while after the boiler stopped firing, this
should be sufficient to carry the heat away without the trip operating.

If it has tripped out because of too much heat, would the act of
turning down the radiator temp knob until it clicks, then putting it
back be enough to reset it? (the boiler in my last house, you had to
take the case off and open a metal enclosure to get to the thermal
cutout reset).

Probably. There are various designs of over-heat stat. On my MkI Baxi Solo
boiler, a little button pops out which has to be pushed in to reset it. On
more recent versions of the same boiler, the reset procedure is to turn the
thermostat knob right down and then back up again. Yours is probably like
that.

I will turn the temp down, and leave 2 rads on full to see if it cuts
down the frequency of tripouts.

Bob


Let us know how you get on!
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!

I will turn the temp down, and leave 2 rads on full to see if it cuts
down the frequency of tripouts.


Let us know how you get on!

Well, I turned the heat down, and put 2 rads on full, and it still cuts out.
I think it is even more than before, but it is a seemingly random thing
anyway.

I think the thermal cutout thing is working, because it can go for a couple
of hours, and the rads do feel hot, so i don't think it is cutting out
early.

I fiddled with the pump. It has 3 speed settings, and all three sound
different, although it may not be fully functional. When the switch is
between settings, the pump stops (break before make switch), and the water
sounds like it is boiling, although it did not cut out (I didn't hold it
there long).

I don't have a thermometer to check the water temperature.

The firing up sequence sounds like:

Demand for heat
flame light comes on dull
small click: fan starts
pause
flame light goes bright
large click (gas valve)
whoomph (gas lights)
flame light goes off (as though it is a "request to light" indicator)

When I find it has cut out, the fan is going, and the light is on bright,
and no gas is being used up.

Bob

In an earlier contribution to this discussion,
Bob Smith wrote:

I will turn the temp down, and leave 2 rads on full to see if it
cuts down the frequency of tripouts.


Let us know how you get on!

Well, I turned the heat down, and put 2 rads on full, and it still
cuts out. I think it is even more than before, but it is a seemingly
random thing anyway.

I think the thermal cutout thing is working, because it can go for a
couple of hours, and the rads do feel hot, so i don't think it is
cutting out early.

I fiddled with the pump. It has 3 speed settings, and all three sound
different, although it may not be fully functional. When the switch
is between settings, the pump stops (break before make switch), and
the water sounds like it is boiling, although it did not cut out (I
didn't hold it there long).

I don't have a thermometer to check the water temperature.

The firing up sequence sounds like:

Demand for heat
flame light comes on dull
small click: fan starts
pause
flame light goes bright
large click (gas valve)
whoomph (gas lights)
flame light goes off (as though it is a "request to light" indicator)

When I find it has cut out, the fan is going, and the light is on
bright, and no gas is being used up.

Bob


This is all very interesting! I'm no longer convinced that it *is* the
overheat stat operating.

When my boiler cuts out on its overheat stat, it cuts power to everything -
so no fan, no LEDs, no ignition.

Unless the internal wiring of your boiler is different from mine (and it may
well be!) the fact that the fan is still running suggests to me that the
prpblem is downstream of the fan - like the pressure switch or ignition
system - or even the main PCB. Whatever it is, it seems that turning it off
and on resets something and gets it going again.

Can you remind me of the make and model of your boiler. Do you have an
installation manual with internal wiring diagrams? Does it have a
fault-finding chart?
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!

Set Square wrote:
In an earlier contribution to this discussion,
Bob Smith wrote:

I will turn the temp down, and leave 2 rads on full to see if it
cuts down the frequency of tripouts.


Let us know how you get on!

Well, I turned the heat down, and put 2 rads on full, and it still
cuts out. I think it is even more than before, but it is a seemingly
random thing anyway.

I think the thermal cutout thing is working, because it can go for a
couple of hours, and the rads do feel hot, so i don't think it is
cutting out early.

I fiddled with the pump. It has 3 speed settings, and all three
sound different, although it may not be fully functional. When the
switch
is between settings, the pump stops (break before make switch), and
the water sounds like it is boiling, although it did not cut out (I
didn't hold it there long).

I don't have a thermometer to check the water temperature.

The firing up sequence sounds like:

Demand for heat
flame light comes on dull
small click: fan starts
pause
flame light goes bright
large click (gas valve)
whoomph (gas lights)
flame light goes off (as though it is a "request to light" indicator)

When I find it has cut out, the fan is going, and the light is on
bright, and no gas is being used up.

Bob


This is all very interesting! I'm no longer convinced that it *is* the
overheat stat operating.

When my boiler cuts out on its overheat stat, it cuts power to
everything - so no fan, no LEDs, no ignition.

Unless the internal wiring of your boiler is different from mine (and
it may well be!) the fact that the fan is still running suggests to
me that the prpblem is downstream of the fan - like the pressure
switch or ignition system - or even the main PCB. Whatever it is, it
seems that turning it off and on resets something and gets it going
again.

Can you remind me of the make and model of your boiler. Do you have an
installation manual with internal wiring diagrams? Does it have a
fault-finding chart?

It is a Ravenheat, with no model number or identification (unless it is
under the plumbers "call me" sticker). There was no manual when we moved
into the house. I could take a picture with and without it's front cover on
(ooer missis!) if that would help.

Bob

In an earlier contribution to this discussion,
Bob Smith wrote:


It is a Ravenheat, with no model number or identification (unless it
is under the plumbers "call me" sticker). There was no manual when
we moved into the house. I could take a picture with and without
it's front cover on (ooer missis!) if that would help.

Bob


It might help someone identify it - not me, I'm afraid - I only know about
the boilers I have owned.

Since you don't have an installation manual, my thoughts were that we may be
able to download one from the maker's website. But we *do* need to know the
model. There may be a plate inside the casing, if it doesn't say on the
outside.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!

It is a Ravenheat, with no model number or identification (unless it
is under the plumbers "call me" sticker). There was no manual when
we moved into the house. I could take a picture with and without
it's front cover on (ooer missis!) if that would help.

Bob


It might help someone identify it - not me, I'm afraid - I only know
about the boilers I have owned.

Since you don't have an installation manual, my thoughts were that we
may be able to download one from the maker's website. But we *do*
need to know the model. There may be a plate inside the casing, if
it doesn't say on the outside.
--

OK, will look for a plate, and peel the plumber's sticker off. Failing
that, I will take some piccies. Then I could find a PDF or something with
te wiring diagram in.

Bob

In an earlier contribution to this discussion,
Set Square wrote:

In an earlier contribution to this discussion,
Bob Smith wrote:


It is a Ravenheat, with no model number or identification (unless it
is under the plumbers "call me" sticker). There was no manual when
we moved into the house. I could take a picture with and without
it's front cover on (ooer missis!) if that would help.

Bob


It might help someone identify it - not me, I'm afraid - I only know
about the boilers I have owned.

Since you don't have an installation manual, my thoughts were that we
may be able to download one from the maker's website. But we *do*
need to know the model. There may be a plate inside the casing, if
it doesn't say on the outside.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!


Just had a look at the Ravenheat site. They do have downloadable manuals -
at least for their current boilers. Have a look at
http://www.ravenheat.co.uk/manuals.htm
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!

Just had a look at the Ravenheat site. They do have downloadable
manuals - at least for their current boilers. Have a look at
http://www.ravenheat.co.uk/manuals.htm

Thanks for that - Had a look at the manuals, looks like a few have the same
casing. Failing all other methods of ID (peeling sticker, finding plate
etc.) I could go to the factory and ask. The address on those leaflets is
in Morley, Leeds, and that's where I live. I know the place, thinking about
it, but just thought it was a ravenheat stockists.

Bob

Thanks for that - Had a look at the manuals, looks like a few have the
same
casing. Failing all other methods of ID (peeling sticker, finding plate
etc.) I could go to the factory and ask. The address on those leaflets is
in Morley, Leeds, and that's where I live. I know the place, thinking
about
it, but just thought it was a ravenheat stockists.

Bob



Right, I found a 1"x1" sticker inside with RSF 82 ET and a barcode on it.
The PDF is online (they still make this thing?) and the picture of the guts
looks like the beast. (
http://www.ravenheat.co.uk/pdf/RSF82/RSF82screenV3.pdf )

The PDF says it is auto modulating though, does this mean it varies the
flame, because I am sure mine burns full blast in short bursts?

Anyway, what's next?

Bob

"Bob Smith" wrote in message ...
Thanks for that - Had a look at the manuals, looks like a few have the
same
casing. Failing all other methods of ID (peeling sticker, finding plate
etc.) I could go to the factory and ask. The address on those leaflets
is
in Morley, Leeds, and that's where I live. I know the place, thinking
about
it, but just thought it was a ravenheat stockists.

Bob



Right, I found a 1"x1" sticker inside with RSF 82 ET and a barcode on it.
The PDF is online (they still make this thing?) and the picture of the
guts
looks like the beast. (
http://www.ravenheat.co.uk/pdf/RSF82/RSF82screenV3.pdf )

The PDF says it is auto modulating though, does this mean it varies the
flame, because I am sure mine burns full blast in short bursts?

Anyway, what's next?

Bob



Just noticed there is a troubleshooting flowchart. The "screen version" is
a bit blurry. I will get the printable version and print it at work

Bob

In message , Bob Smith writes
Right, I found a 1"x1" sticker inside with RSF 82 ET and a barcode on it.
The PDF is online (they still make this thing?) and the picture of the guts
looks like the beast. (
http://www.ravenheat.co.uk/pdf/RSF82/RSF82screenV3.pdf )

The PDF says it is auto modulating though, does this mean it varies the
flame, because I am sure mine burns full blast in short bursts?

Anyway, what's next?

Have you followed the fault finding flow charts on page 40 and 41?

--
Richard Faulkner

Richard Faulkner wrote:
In message , Bob Smith writes
Right, I found a 1"x1" sticker inside with RSF 82 ET and a barcode
on it. The PDF is online (they still make this thing?) and the
picture of the guts looks like the beast. (
http://www.ravenheat.co.uk/pdf/RSF82/RSF82screenV3.pdf )

The PDF says it is auto modulating though, does this mean it varies
the flame, because I am sure mine burns full blast in short bursts?

Anyway, what's next?

Have you followed the fault finding flow charts on page 40 and 41?

I am getting the printable one right now. (the screen version one was a bit
blurry and unreadable).

Bob

Anyway, what's next?

Have you followed the fault finding flow charts on page 40 and 41?


Right, I followed the flowchart, and in normal operation, I fall off the
bottom of the flowchart, everything being hunky dory most of the time.

When I find the boiler in it's "stupid" state, it either has not turned the
gas on, or not lit when it tried to turn the gas on. The flowchart suggests
checking the gas valve or the spark electrode respectively. Also could be a
pilot injector blockage.

Are any of these items known to be intermittently faulty? I can't see the
gas valve being affected by temperature, and the pilot and spark electrode
are only required at the beginning of each lightup (and so should have
cooled a bit)

Any ideas?

Bob

On Fri, 16 Jan 2004 20:10:47 +0000, Bob Smith wrote:


Anyway, what's next?

Have you followed the fault finding flow charts on page 40 and 41?


Right, I followed the flowchart, and in normal operation, I fall off the
bottom of the flowchart, everything being hunky dory most of the time.

When I find the boiler in it's "stupid" state, it either has not turned the
gas on, or not lit when it tried to turn the gas on. The flowchart suggests
checking the gas valve or the spark electrode respectively. Also could be a
pilot injector blockage.

Are any of these items known to be intermittently faulty? I can't see the
gas valve being affected by temperature, and the pilot and spark electrode
are only required at the beginning of each lightup (and so should have
cooled a bit)


If the ignition becomes marginal then a slight change in the conditions
(such as temperature, gas pressure, supply voltage perhaps) can make all
the difference between working and not working.

The gas valve is probably the least likely item to go wrong.
The spark electrode, pilot jet or gas pressure and likely items.


--
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