andrews 24/39, Installation Manual, Operation And Service Manual

Page: 18 / 96

18
VENTED SYSTEMS, STANDARD RANGE
The water heater must be supplied from a cold water feed cistern and the hot water
supply pipe must be fitted with an open vent pipe in accordance with BS 5546 and
BS 6644.
The Water Supply (Water Fittings) Regulations 1999 must be observed when installing
the system.
The cold water feed cistern must have an actual capacity greater than the hourly
recovery rate of the heater or heaters to which it is fitted, the minimum actual capacity
allowed for a feed cistern being 227 litres (50 gallons).
The actual cistern capacity is the capacity to the normal water line of the cistern.
All cisterns should be manufactured to the relevant British Standard.
The distance from the normal water line to the top of the cistern should comply with that
specified by the Water Authorities.
The cold water inlet and hot water outlet connection nipples are identified on top of the
heater. Remove nipples and re-make prior to installation.
Connect the cold water feed and hot water outlet to these nipples with union adaptors
for ease of servicing.
CAUTION!
DO NOT APPLY HEAT TO THESE NIPPLES IF MAKING CAPILLARY SOLDERED
JOINTS AS THEY ARE FITTED WITH PLASTIC INSERTS. MAKE THE CAPILLARY
JOINTS TO THE PIPES BEFORE CONNECTING TO THE HEATER. A DRAIN COCK IS
SUPPLIED WITH THE HEATER AND THIS SHOULD BE FITTED TO THE APPROPRIATE
BOSS AS SHOWN ON THE DRAWING.
After installation of the water system, open the main water supply valve, flush the system
and fill the heater.
Open the hot taps to allow air to escape from the system.
When the water is free of air, close the taps and check for leaks at the gas control
thermostat, drain cock and the pipe connections at the top of the heater.
All water connections for Standard Range are shown in Fig 6.
Typical water service layout for Standard Range single heater vented system is
shown in Fig. 6A.
Typical water service layout for Standard Range multiple heater vented system is
shown in Fig. 7.
INSTALLATION SECTION 3
WATER
CONNECTIONS
Fig 6.
Cold Water
Inlet
T&P Valve Tapping
84/87 only
Drain & Secondary
Return Tapping
1
Hot Water
outlet
All connection sizes are
shown on page 4
T&P Valve Tapping