andy smith wrote:

BigWallop wrote:
Its that time of year when the cannon gas fire (inset flame type)
gets more used ...
having read about smoke test on this group and in manual...
I thought I give mine a test using some of those smoke matches from
screwfix...

Smoke match seemed to give great clouds of smoke for 10 sec followed
by smaller smoke stream
for about 10 sec (like that from a cigarette).... is this how they
are supposed to burn?

tested with all doors closed and fire on full blast for 10 mins...
with smoke match positioned as per manual (20mm down and
20mm inside canopy).... only about half smoke went up chimney in
first 10 secs...
whereas all of it get drawn up flue in next 10 secs (when match was
generating less smoke)...

repeated with doors open (more ventilation) ... same result....
repeated after having chimney swept ... same result ...

Have I got a problem... manual is a bit unhelpful as it say check
that "most of smoke" goes up chimney...

one other thing, chimney flue is about 177mm square... gas fire has
a "spigot restrictor" in place (plate covering about
half of exit from gas fire to flue) ... manual say it should be
removed if flue is 125mm... no other explanation
but do you think it should be removed in my case (what's its
purpose)? I've seen installation manuals for other makes of similar
fires say to leave restrictor in place if fire installed in
class 1 flue of "good" class 2?

PS gas fire originally fitted by "corgi approved" plumber for what
its worth...

Andy




This is how I was taught to carry out a spillage test.

Close all doors and windows to the room containing the appliance. Let
the fire run on HIGH for five minutes. Take a smoke match, light it,
and using a smoke match tube, hold it at the top edge of the fire
opening, 25mm down and 25mm in. Starting 50mm in from either side,
run the smoke match across the opening. All the smoke should be
drawn away up the flue. Any smoke returning into the room indicates
that spillage is occurring. If the initial spillage test fails, run
the fire for a further 10 minutes and repeat the test. When the test
has been completed satisfactorily and no spillage occurs, then repeat
the test with any extractor fans in the premises running on the
highest setting, and any communicating doors open. Finally, repeat
with all doors open.

If spillage is still indicated after undertaking all of the above,
there may be a fault in the flue, or insufficient ventilation is
present. If the problem cannot be easily rectified, then expert
advice should be sought.

Thanks - I notice you use a smoke match tube... (online supplier?)
...I just stuck a match on
the end of a stick (fire was too hot to hold in hand)... would a proper
tube
regulate how the smoke was produced (my matches claim burn time of 20sec
but most smoke produced in first 10sec)....

Any thought on "spigot restrictor"?

I'll try again and if in doubt I'll get in Corgi...

Well it would be helpful to learn from the experienced fitter...

The screwfix matches are not very good, I have had several that failed
to light and several that went out in use. I will buy from elsewhere
when my existing stock are finished.


--
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