12
Depending on the water demand pattern (e.g., small
amounts frequently), it may be necessary to circulate the
water in the heater to prevent temperature stratification.
Therefore, we recommend that a circulation system is
installed in the event of such demand patterns (see
diagram 7)
1
Pump (type: Grundfos UP 20-15 N 150 or equivalent)
2
Non-return valve
3
Gate valve
4
Drain valve
A Cold water
B Hot water
C Return circulation
D Gas supply
2.1.3 Gas connection
The gas supply to this appliance must be installed in
accordance with BS 6891 (1988) and British Gas
Publications Up1 and UP2.
Fit the ¾” gas supply cock supplied with this unit
immediately before the gas control block. No heat or
soldered joints should be applied in the vicinity of the
gas control block, as they could cause damage to the
control.
All connections and joints should be tested for gas
soundness with a suitable leak detector (do not use a
naked flame)
NB. When operating this unit on LPG a suitable gas
supply cock should be used)
2.1.4 Flue system
The water heater should be fitted with a flue system
connected to the draught diverter. The flue pipe should
rise for at least 50 cm. vertically before the inclusion of
any bends. If a horizontal run of flue is required this
should be kept to a minimum length possible and
incorporate a rise of 6 cm. per metre of run. A split clip or
flange should be provided in the flue close to the
draught diverter for ease of servicing.
All flue materials should be corrosion resistant i.e.
stainless steel or galvanised and must include a tested
and approved terminal to BS 5440 part I.
Diagram 7 – Connection diagram including
destratification circulation system
2.1.5 Flue-gas discharge
The horizontal draught diverter supplied separately must
be used to connect the heater to the chimney
The draught diverter can be turned to ensure that the
distance to the discharge duct is as short as possible.
Once the position has been determined, drill two small
holes (3.2 mm.) to fix the support bracket (fitted to the
pallet) below the draught diverter (see diagram 8).
Diagram 8 – Position draught diverter