When my gas boiler is on and it's quite windy outside the flames are
affected by the wind quite a bit - as if it's windy where the flames
are yet as its an old type the inlet air comes from the house and the
outlet is a stack running from the ground floor to the roof guttering
line and has no faults / holes etc I can see and looks in good
condition and has a berathing type cap on the top. What's going on?

I have a CO monitor and the level increases (still within safe limits)
when this occurrs so obviously it's not burning properly.....

405 TD Estate wrote:
When my gas boiler is on and it's quite windy outside the flames are
affected by the wind quite a bit - as if it's windy where the flames
are yet as its an old type the inlet air comes from the house and the
outlet is a stack running from the ground floor to the roof guttering
line and has no faults / holes etc I can see and looks in good
condition and has a berathing type cap on the top. What's going on?

I have a CO monitor and the level increases (still within safe limits)
when this occurrs so obviously it's not burning properly.....

It sounds like the wind is affecting the amount of draw the chimney
stack is providing and hence altering the air rate at the burner.

--
Cheers,

John.

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In article ,
John Rumm writes:
405 TD Estate wrote:
When my gas boiler is on and it's quite windy outside the flames are
affected by the wind quite a bit - as if it's windy where the flames
are yet as its an old type the inlet air comes from the house and the
outlet is a stack running from the ground floor to the roof guttering
line and has no faults / holes etc I can see and looks in good
condition and has a berathing type cap on the top. What's going on?

I have a CO monitor and the level increases (still within safe limits)
when this occurrs so obviously it's not burning properly.....

It sounds like the wind is affecting the amount of draw the chimney
stack is providing and hence altering the air rate at the burner.

It could be forcing fumes back down the chimney, which then
get used as the burner air intake, and with reduction of
oxygen present, cause CO increase. Has anything been built
up around the height of the chimney outside since the chimney
was built which might be interfering with the airflow up there?
What sort of ait intake is there into the room from outside?

Boiler shouldn't be producing much CO in the first place if
it's been properly serviced. Has it been regularly serviced?
That's really important with an open flued boiler.
What level of CO are you observing?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 5 Nov, 19:19, (Andrew Gabriel) wrote:
In article ,
John Rumm writes:

405 TD Estate wrote:
When my gas boiler is on and it's quite windy outside the flames are
affected by the wind quite a bit - as if it's windy where the flames
are yet as its an old type the inlet air comes from the house and the
outlet is a stack running from the ground floor to the roof guttering
line and has no faults / holes etc I can see and looks in good
condition and has a berathing type cap on the top. What's going on?

I have a CO monitor and the level increases (still within safe limits)
when this occurrs so obviously it's not burning properly.....

It sounds like the wind is affecting the amount of draw the chimney
stack is providing and hence altering the air rate at the burner.

It could be forcing fumes back down the chimney, which then
get used as the burner air intake, and with reduction of
oxygen present, cause CO increase. Has anything been built
up around the height of the chimney outside since the chimney
was built which might be interfering with the airflow up there?
What sort of ait intake is there into the room from outside?

Boiler shouldn't be producing much CO in the first place if
it's been properly serviced. Has it been regularly serviced?
That's really important with an open flued boiler.
What level of CO are you observing?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

There is a vent block into the kitchen all be it behind cupboards but
they would not stop the flow of air so I would be happy air can be
drawn into the kitchen - also the kitchen is open to the rest of the
house so it could draw air from there. What I find strange is the
chimney - a 6" diameter (roughly) pipe is very very long - upto the
roof guttering and yet the wind which can only blow across the top of
it (and it has a rain cap type thing on as well) can affect the flame
probably 15 feet below!

I've just had a thought - perhaps the rest of the house is put under
+ve pressure with the wind (wind blowing on one side of the house or
something) and there is a -ve pressure as the wind blows across the
top of the exhaust chimney so too much air passes through the boiler?
Sound plausable?

On 5 Nov, 19:19, (Andrew Gabriel) wrote:
In article ,
John Rumm writes:

405 TD Estate wrote:
When my gas boiler is on and it's quite windy outside the flames are
affected by the wind quite a bit - as if it's windy where the flames
are yet as its an old type the inlet air comes from the house and the
outlet is a stack running from the ground floor to the roof guttering
line and has no faults / holes etc I can see and looks in good
condition and has a berathing type cap on the top. What's going on?

I have a CO monitor and the level increases (still within safe limits)
when this occurrs so obviously it's not burning properly.....

It sounds like the wind is affecting the amount of draw the chimney
stack is providing and hence altering the air rate at the burner.

It could be forcing fumes back down the chimney, which then
get used as the burner air intake, and with reduction of
oxygen present, cause CO increase. Has anything been built
up around the height of the chimney outside since the chimney
was built which might be interfering with the airflow up there?
What sort of ait intake is there into the room from outside?

Boiler shouldn't be producing much CO in the first place if
it's been properly serviced. Has it been regularly serviced?
That's really important with an open flued boiler.
What level of CO are you observing?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

upto 10ppm for short times. (when boiler is on)

405 TD Estate wrote:

I've just had a thought - perhaps the rest of the house is put under
+ve pressure with the wind (wind blowing on one side of the house or
something) and there is a -ve pressure as the wind blows across the
top of the exhaust chimney so too much air passes through the boiler?
Sound plausable?

Just blowing across the top of a pipe will cause a pressure drop that
will tend to suck a fluid up the pipe.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
405 TD Estate wrote:

re wind blowing affecting the flame, this is bound to happen with
your type of flue. As long as its not going out, is burning ok and is
not polluting the indoor air, no problem. Someone else will be able
to tell more re the CO levels.


I've just had a thought - perhaps the rest of the house is put under
+ve pressure with the wind (wind blowing on one side of the house or
something) and there is a -ve pressure as the wind blows across the
top of the exhaust chimney so too much air passes through the boiler?
Sound plausable?

Just blowing across the top of a pipe will cause a pressure drop that
will tend to suck a fluid up the pipe.

Yes, though IRL the wind will travel in various directions, often
turbulent, so it will blow both in and out of the pipe to some degree.


NT