Flue Draft Test - Wohler DM 2000 Notice D'utilisation

Flue Draft Test

4 Flue Draft Test
Safety Warning!
You must be qualified to work on heat appliances and gas, oil or other fuel supplies. For
further instructions contact your local authorities before you start the job.
Choosing the correct place for
measuring
14
The constant flow of flue gases at the correct rate of
flow with the least possible variation is required for
safe and efficient combustion. Insufficient flue draft
will cause ignition difficulties and is likely to result in
fume emission and potential health risk. Too much
draft will make control of the fire difficult and may
result in overheating. In this instance, fitting a draft
stabiliser may be required. An appliance manufac-
turer will specify a range of flue draft conditions
under which their appliance will operate.
The correct place for measuring the chimney draft is
close to the appliance and at least 2 x flue-pipe
diameter above the spigot and 15 cm away from any
draft stabiliser. Some appliances include purpose
made flue draught test points for insertion of test
equipment sampling probes. Where no purpose-
made flue draught point is included a suitable point
will need to be provided adjacent to the appliance
outlet. In some instances, a draft measurement can
be taken by temporarily removing a sweeping ac-
cess cover and using a cone or plate with a hole in
the centre to prevent secondary air entry and to
enable the sampling probe to be inserted.
A flue draught reading should be taken before the
appliance is lit to identify any potential problems
which will result from down draught.