Andrews WH and WHX Multiple Water Heater Installation with ST Range Storage Cylinder and
Secondary Return
Fig No.12
Gas
Supply
HWS flow
Hot Outlets
Storage
Cylinder
Tank thermostat kit (part
no. C927) set to 65ºC
Bronze secondary
pump
Cold Supply
NB. Size mains pressure group to
suit building design flow rate
Gas rate for NG units
WH42 - 5.1 m
3
/hr
WH56, WHX56 - 6.5 m
3
/hr
Gas rate for Propane units
LWH42 - 1.9 m
3
/hr
LWH56, LWHX56 - 2.5 m
3
/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1
2
3
4
4
5
6
7
1. Stop cock
2. Strainer
3. Pressure reducing valve
4. Non return valve
5. Expansion vessel
6. Expansion valve + tundish
7. Andrews bronze pump c/w ball
valve unions (part no. B249)
8. Combined temperature
and pressure relief valve
+ tundish
When using multiple units in conjunction
with a storage vessel the full output of all
heaters is required to provide maximum
recovery volume. In this case the primary
pump must be sized to give 8 litres/min
for each heater. See Fig No’s. 12 and 13.
Pump
(See Fig.
No’s. 12/13)
Remote
controller
kit (part no
B285)*
*An Electronic System
Controller Kit can be used
as an alternative when
manifolding up to six units.
(see Fig. No’s 6 and 8)
Please refer to the
FASTflo Specification
Sheet and Flue Selection
Guide for Flue Kit and
termination details
6
8
Summary of Contents for WH42
Page 18: ...Dimensions WH42 LWH42 WH56 and LWH56 Fig No 15...
Page 19: ...Dimensions WHX56 and LWHX56 Fig No 16...
Page 20: ...WH42 LWH42 WH56 and LWH56 Pre assembled dual manifold unit dimensions Fig No 17...
Page 21: ...WH42 LWH42 WH56 and LWH56 Pre assembled triple manifold unit dimensions Fig No 18...
