FASTflo WH42 Guía
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FASTflo
Installation Design Guide
This manual must be kept with the appliance October 2010
Part No E835
Continuous Flow Wall Hung Balance Flue
Water Heaters for Natural Gas an Propane
WH42, WH56, WHX56, LWH56, WHX56, LWHX56
Repro uction of any information in this publication by any metho is not permitte
unless prior written approval has been obtaine from An rews Water Heaters.
An rews Storage Water Heaters have been esigne an manufacture to comply
with current international stan ar s of safety. In the interests of the health an safety
of personnel an the continue safe, reliable operation of the equipment, safe working
practices must be employe at all times. The attention of UK users is rawn to their
responsibilities un er the Health an Safety Regulations 1993.
All installation an service on An rews Water Heaters must be carrie out by properly
qualifie personnel an , therefore, no liability can be accepte for any amage or
malfunction cause as a result of intervention by unauthorise personnel.
An rews Water Heaters’ policy is one of continuous pro uct improvement an ,
therefore, the information in this manual, whilst completely up to ate at the time of
publication, may be subject to revision without prior notice.
Further information an assistance can be obtaine from:
An rews Water Heaters
Woo Lane, Er ington,
Birmingham B24 9QP
Tel: 0845 070 1055
Fax: 0845 070 1059
Email: an rews@baxigroup.com
Website: www.an rewswaterheaters.com
THE ANDREWS WATER HEATERS COVERED IN THIS GUIDE
ARE FOR USE WITH NATURAL GAS OR PROPANE ONLY
Copyright An rews Water Heaters 2010
Andrews Installation Design Guide for WH and WHX Model Water Heaters
Fig No. DESCRIPTION
1Typical Installation - Single Heater
2Typical Installation - Single Heater with Secondary Return
3Typical Installation - Two Heaters
4Typical Installation - Two Heaters with Quick Connect Cord
5Typical Installation - Three Heaters with Secondary Return
6Typical Installation - Four Heaters with Electronic System Controller Kit
7Technical Note - Water Flow Rates and Performance Chart
8Typical Installation - Electronic System Controller Kit
9Technical Note - Unvented System Kits
10 Typical Installation - Single Heater with ST Range Storage Cylinder
11 Typical Installation - Two Heaters with ST Range Storage Cylinder,
Quick Connect Cord and Secondary Return
12 Typical Installation - Three Heaters with ST Range Storage Cylinder
and Secondary Return
13 Technical Note - Flow Rate Head Loss and Pump Sizing
14 Technical Note - Pump Curves
15 Heater Dimensions - WH56 and LWH56
16 Heater Dimensions - WHX42, LWHX42, WHX56 and LWHX56
17 WH42, LWH42, WH56 and LWH56 Pre-assembled dual manifold unit dimensions
18 WH42, LWH42, WH56 and LWH56 Pre-assembled triple manifold unit dimensions
19 WHX56 and LWHX56 Pre-assembled dual manifold unit dimensions
20 WHX56 and LWHX56 Pre-assembled triple manifold unit dimensions
Please refer to the
FASTflo Specification
Sheet and Flue Selection
Guide for Flue Kit and
termination details
Remote controller kit
(part no. B285)
Gas
HWS flow
Hot Outlets
Water Supply Pressure
Min 1.0 bar
Max 10.0 bar
Min flow 3.5 ltrs/min
1. Stop cock
Gas rate for NG units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas rate for Propane units
LWH42 - 1.9 m3/hr
LWH56, LWHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1
Andrews WH and WHX Single Water Heater Installation Without Secondary Return
Fig No.1
Cold Supply
Please refer to the
FASTflo Specification
Sheet and Flue
Selection Guide for
Flue Kit and
termination details
Remote controller kit
(part no. B285)
Gas
HWS flow
Hot Outlets
Cold Supply
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)
Water Supply Pressure
Min 1.0 bar
Max 10.0 bar
Min flow 3.5 ltrs/min
Bronze secondary return pump
see Fig. No’s. 13 and 14
Gas rate for NG units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas rate for Propane units
LWH42 - 1.9 m3/hr
LWH56, LWHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
123 4
5
6
7
Andrews WH and WHX Single Water Heater Installation with Secondary Return
Fig No.2
Remote controller kit
(part no. B285)
Gas
HWS flow Where output may be below
7 ltrs/min see Fig. No. 4
Cold Supply
1. Stop Cock
Water Supply Pressure
Min 1.0 bar
Max 10.0 bar
Gas rate for NG units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas rate for Propane units
LWH42 - 1.9 m3/hr
LWH56, LWHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1
Andrews WH and WHX Multiple Water Heater Installation without Secondary Return
Fig No.3
Please refer to the
FASTflo Specification
Sheet and Flue Selection
Guide for Flue Kit and
termination details
Andrews WH and WHX Multiple Water Heater Installation with Quick Connect Cord Kit
Fig No.4
Single remote
controller
Gas
HWS flow
Hot Outlets
Cold Supply
1. Stop Cock
Water Supply Pressure
Min 1.0 bar
Max 10.0 bar
Quick Connect Cord Kit
(part no. B286)
Gas rate for NG units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas rate for Propane units
LWH42 - 1.9 m3/hr
LWH56, LWHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1
Please refer to the
FASTflo Specification
Sheet and Flue Selection
Guide for Flue Kit and
termination details
Andrews WH and WHX Multiple Water Heater Installation with Secondary Return
Fig No.5
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)
Gas
HWS flow
Hot Outlets
Cold Supply
Bronze secondary return pump
see Fig. No’s. 13 and 14
Gas rate for NG units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas rate for Propane units
LWH42 - 1.9 m3/hr
LWH56, LWHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1 2 3 4
7
5
6
4
Please refer to the
FASTflo Specification
Sheet and Flue Selection
Guide for Flue Kit and
termination details
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)
Andrews WH56 and WHX56 Multiple Water Heater Installation with System Controller Kit
Fig No.6
Single remote
controller
System Controller in unit No. 1
(see Fig. No. 8)
Gas
HWS flow
Hot Outlets
Cold Supply
Gas rate per NG units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas rate for Propane units
LWH42 - 1.9 m3/hr
LWH56, LWHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1
1. Stop Cock
Water Supply
Pressure
Min 1.0 bar
Max 10.0 bar
Please refer to the
FASTflo Specification
Sheet and Flue
Selection Guide for
Flue Kit and
termination details
Andrews WH and WHX Water Flow Rates
Performance Chart
Fig No.7
Andrews Model Temperature Temperature Temperature Temperature Temperature Temperature
Reference
Rise 25ºC Rise 35ºC Rise 45ºC Rise 55ºC Rise 65ºC Rise 75ºC
L sec L min L sec L min L sec L min L sec L min L sec L min L sec L min
WH42,LWH42 0.40 24.0 0.29 17.4 0.22 13.2 0.18 10.8 0.15 9.2 0.13 8.0
WH56, LWH56 0.53 31.8 0.38 22.8 0.30 18.0 0.24 14.4 0.20 12.3 0.18 10.6
WHX56,LWHX56 0.53 31.8 0.38 22.8 0.30 18.0 0.24 14.4 0.20 12.3 0.18 10.6
The flow rate will vary dependant upon the temperature selected at outlet and the incoming water temperature.
The flow rate can be calculated using the following formula or by reference to the charts above.
In addition to the above the maximum flow through each heater is pre-set independent of temperature, maximum flow rate for the
WH42 is 24 L/min and maximum flow rate for the WH56 and WHX56 is 31.8 L/min.
WH42, LWH42 = 42 kW output
WH56, LWH56 = 55.8kW output
WHX56, LWHX56 = 55.8 kW output
(heater output) kW
Δt (temperature rise) x 4.2 specific heat
Flow rate L/S =
Water flow
at different
temperature
rises
Este manual sirve para los siguientes modelos
4
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