Technical information

• COMBUSTION GAS REMOVAL
Flue: A draught diverter is fitted to the top of the water heater.The nominal flue
size is 90 mm. (D61B, D61E) and 110 mm. (G11E). In exposed situations, twin-
walled flue pipe should be used. A minimum length of vertically rising flue of 600
mm. must be provided to ensure the water heater’s produts of combustion are
completely evacuated. If single wall flue pipe is being used which has to pass
through combustible materials, provide a metal sleeve of 115 mm. diameter which
allows an air gap of 25 mm.
The flue shall not run into chimmeys for removing combustion products from solid
or liquid fuels. Flue pipes and terminals should comply with BS 715. Terminals
shall not be sited within 300 mm. of a ventilator o open window. In the U. K full
details of flueing requirements are given in BS 5440 Part 1.
The flow rate of the combustion gases is 14 m
3
/h (G-30 and G-31), and the
temperature of the combustion gases at the exit draught diverter hood is
137ºC (Model D61E, D61B).
The flow rate of the combustion gases is 41,4 m
3
/h (G-30 and G-31), and 44,4
m
3
/h (G-20 and G-25). The temperature of the combustion gases at the exit
draught diverter hood is 160ºC (Model G11E).
This appliance is fitted with a device to monitor the removal of combustion
gases, which cuts off the supply of gas to the burner, thereby turning of the
appliance.
The function of this device is to prevent the combustion gases from getting into
the premises where the appliance is installed when there are problems with their
removal due to adverse weather conditions or incorret draught in the flueway.
It is a safety device to ensure that the combustion gases are removed properly.
This device should never be taken out of service, as this would mean a lack of
safety in the correct operation of the appliance.
Whenever any repairs are made to this device, only original parts should be fitted.
A check should always be made to ensure that the appliance works correctly. The
procedure is as follows:
a) Turn the appliance on.
b) If air does not blow back through the flueway due to bad weather conditions
(too much wind), the control device should not stop the appliance, at least
during 30 minutes of continouus operation.
If this test is carried out satisfactorily, the appliance is in perfect operating
condition.
If the appliance repeatedly turns off, this means that the combustion gases are not
being removed correctly. The problem should be resolved by taking the
appropriate steps.
• AIR SUPPLY FOR COMBUSTION
Air Requirements: Reference is made to BS 5482 (BS EN 1949) and EN 721
covering ventilation requirements for permanent dwellings, caravans and boats.
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