andrews WH42 Guide

INSTALLATION DESIGN GUIDE
Andrews. Built to perform.
Please read and understand these instructions before commencing installation and leave this manual with the customer for future reference.
.);<V
+VU[PU\V\ZV^^HSSO\UNIHSHUJLK\L^H[LYOLH[LYZMVY6H[\YHS/HZHUK8YVWHUL
WH42, WH56, WHX56, LWH56, WHX56, LWHX56, WHC56, LWHC56
Part number E835

2 Draft A 18/07/16
Andrews Water Heaters
Reproduction of any information in this publication by any
method is not permitted unless prior written approval has been
obtained from Andrews Water Heaters.
Andrews Storage Water Heaters have been designed and
manufactured to comply with current international standards of
safety. In the interests of the health and safety of personnel and
the continued safe, reliable operation of the equipment, safe
working practices must be employed at all times. The attention
of UK users is drawn to their responsibilities under the Health
and Safety Regulations 1993.
All installation and service on Andrews Water Heaters must be
carried out by properly qualified personnel and, therefore, no
liability can be accepted for any damage or malfunction caused
as a result of intervention by unauthorised personnel.
Andrews Water Heaters’ policy is one of continuous product
improvement and, therefore, the information in this manual,
whilst completely up to date at the time of publication, may be
subject to revision without prior notice.
Further information and assistance can be obtained from:
Customer support
Monday - Friday
8am - 5pm
ales: 0345 070 1055
Technical: 0345 070 1057
Email: [email protected]
Website: www.andrewswaterheaters.co.uk
Twitter: @andrewsWH
Copyright Andrews Water Heaters 2016

Draft A 18/07/16 3
Contents
Contents
1 Installations
1.1 WH and WHX single water heater installation without secondary return
1.2 WH and WHX single water heater installation with secondary return
1.3 WH and WHX multiple water heater installation without secondary return
1.4 WH and WHX multiple water heater installation with quick connect cord kit
1.5 WH and WHX multiple water heater installation with secondary return
1.6 WH56 and WHX56 multiple water heater installation with system controlller kit
1.7 WH and WHX single water heater installation with ST range storage cylinder
1.8 WH and WHX multiple water heater installation with ST range storage cylinder, quick
connect cord kit and secondary return
2 Water flow rates
2.1 WH and WHX water flow rates
3 Controller kit
3.1 System controller kit (part no. B287) for WH56, WH56 and WHX56
4
4
4
5
5
6
6
7
7
8
8
9
9
FA Tflo Installation design guide for WH and WHX model water heaters

4 Draft A 18/07/16
1 Installations
1 Installations
1.1 WH and WHX single water heater installation without secondary return
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 upply Pressure
Min 1.0 bar
Max 10.0 bar
Min flow 3.5 ltrs/min
Gas Rate for NG Units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas Rate for Propane Units
WH42 - 1.9 m3/hr
WH56, WHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1
Cold Supply
1. Stop Cock
Fig. 1
1.2 WH and WHX single water heater installation with secondary return
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
Bronze secondary return pump
Hot Outlets
Water upply Pressure
Min 1.0 bar
Max 10.0 bar
Min flow 3.5 ltrs/min
Gas Rate for NG Units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas Rate for Propane Units
WH42 - 1.9 m3/hr
WH56, WHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
12 34
5
6
7
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)
Fig. 2

Draft A 18/07/16 5
Installations 1
1.3 WH and WHX multiple water heater installation without secondary return
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 Where output may
be below 7 ltrs/min
see Fig. 4
Water upply 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
WH42 - 1.9 m3/hr
WH56, WHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1
Cold Supply
1. Stop Cock
Fig. 3
1.4 WH and WHX multiple water heater installation with quick connect cord kit
Please refer to the FASTflo
specification sheet and flue
selection guide for flue kit and
termination details.
Single remote
controller
Gas
HWS flow
Quick connect cord kit
(part no. B286)
Hot Outlets
Water upply 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
WH42 - 1.9 m3/hr
WH56, WHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1
Cold Supply
1. Stop Cock
Fig. 4

6 Draft A 18/07/16
1 Installations
1.5 WH and WHX multiple water heater installation with secondary return
Please refer to the FASTflo
specification sheet and flue
selection guide for flue kit and
termination details.
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. 6 and 10)
Gas
HWS flow
Cold supply
Bronze secondary return pump Hot outlets
1234
4
5
6
7
Gas Rate for NG Units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas Rate for Propane Units
WH42 - 1.9 m3/hr
WH56, WHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
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)
Fig. 5
1.6 WH56 and WHX56 multiple water heater installation with system controller kit
Please refer to the
FASTflo specification
sheet and flue
selection guide for
flue kit and
termination details.
Single remote
controller
Gas
HWS flow
System controller in
unit No.1 (see Fig. 10)
Hot Outlets
Water upply
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
WH42 - 1.9 m3/hr
WH56, WHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1
Cold Supply
1. Stop Cock
Fig. 6

Draft A 18/07/16 7
Installations 1
1.7 WH and WHX single water heater installation with T range storage cylinder
Please refer to the FASTflo
specification sheet and flue
selection guide for flue kit and
termination details.
Remote
controller
set to 70°C
Gas
HWS flow
Cold supply
Tank thermostat kit (part no.
C927) set to 65°C
NB. size mains pressure group
to suit building design flow rate
Storage
cylinder
Pump
Hot outlets
1234
5
6
7
8
Gas Rate for NG Units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas Rate for Propane Units
WH42 - 1.9 m3/hr
WH56, WHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
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
Fig. 7
1.8 WH and WHX multiple water heater installation with T range storage cylinder,
quick connect cord kit and secondary return
Please refer to the
FASTflo specification
sheet and flue selection
guide for flue kit and
termination details.
Remote controller
set to 70°C
Storage
cylinder
Pump
Quick connect cord kit
(part no. B286)
Cold supply
NB. Size mains pressure group to
suit building design flow rate
Bronze secondary pump
Tank thermostat kit (part
no. C927) set to 65°C
Gas
HWS flow
Hot Outlets
Gas Rate for NG Units
WH42 - 5.1 m3/hr
WH56, WHX56 - 6.5 m3/hr
Gas Rate for Propane Units
WH42 - 1.9 m3/hr
WH56, WHX56 - 2.5 m3/hr
Dynamic Pressure
NG 20 mbar
Propane 37 mbar
1234
5
6
7
8
Fig. 8
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

8 Draft A 18/07/16
2 Water flow rates
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 referance 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 /min and maximum flow rate for the WH56
and WHX56 is 31.8 /min.
WH42, WH42 = 42 kW output
WH56, WH56 = 55.8 kW output
WHX, WHX56 = 55.8 kW output
Flow rate /S = (Heater output) kW
∆t (temperature rise) x 4.2 specific heat
2 Water Flow Rates
2.1 WH and WHX water flow rates
Performance Chart
Andrews Model Temperature Temperature Temperature Temperature Temperature Temperature
Reference Rise 25°C Rise 35°C Rise 45°C Rise 55°C Rise 65°C Rise 75°C
sec min sec min sec min sec min sec min sec min
WH42, WH42 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, WH56 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, WHX56 0.53 31.8 0.38 22.8 0.30 18.0 0.24 14.4 0.20 12.3 0.18 10.6
Water flow
at different
temperature
rises
Fig. 9

Draft A 18/07/16 9
Controller kit 3
3 Controller kit
3.1 ystem controller kit (part No. B287) for WH56, LWH56 and WHX56
The System Controller Kit can be used as an alternative to the
Quick Connect Cord Kit (two unit installation) or for controlling
up to six manifolded water heaters.
The master unit (No.1) contains the System Controller module
and includes plug connectors to enable the control cords from
the other units to be connected up to the master unit.
In addition the System Controller incorporates the following
standard features, BEMS fault indication, Remote `Power On'
indication, Primary Pump connection via cylinder thermostat,
Secondary Circulation Pump connection and Remote Switching.
A comprehensive installation manual is available from our sales
department.
ystem operation
The control panel randomly selects some heaters at the ready
stage and some at the standby stage, and heaters will start
dependent upon water flow and temperature settings.
The system rotates the lead and standby units after every eight
hours operating time.
As the flow rates increases additional units will fire thus
maintaining the required system flow temperature.
The remote controller must be connected to Unit No.1 and
temperature settings on this controller will be communicated to
the other manifolded heaters on the system.
The System Controller is not required when the installation
incorporates a storage cylinder / buffer vessel or if a constant
large volume of hot water is required.
P
C
B
P
C
B
P
C
B
P
C
B
P
C
B
P
C
B
Unit No. 1
Unit No.2
Unit No.3
Unit No. 4Unit No.5
Unit No.6
System controller kit
(Part No. B287)
Typical installation
Single remote
controller
Fig. 10

10 Draft A 18/07/16

© Copyright
All technical and technological information contained in these technical instructions, as well as any drawings and technical
descriptions supplied, remain our property and shall not be multiplied without our prior consent in writing. Subject to alterations.

Andrews. Built to perform.
Customer support
Monday - Friday
8am - 5pm
Sales
0345 070 1055
Technical
0345 070 1057
Website
andrewswaterheaters.co.uk
Twitter
@AndrewsWH
Register now to activate your warranty www.andrewswaterheaters.co.uk/register-a-warranty.
Please make sure you attach proof of purchase for your warranty to be monitored.
All descriptions and illustrations provided in this document have been carefully prepared but
we reserve the right to make changes and improvements in our products which may affect the
Conditions of Sale which are available on request.
July 2016
ICOM
Energy Association
.);<Vc16;TALLA<176)6,,-;1/6/=1,-671
<
A
A
LALT;61cV<;).     -,1=/6/1;-,,6)                
   
ou attach proof of purchase foryPlease make sure
w to activateoRegister n
ve the right to make changes and imprrwe rese
lu
l
llustrations pr
l descriptions and i
il
l
ll descriptions and i
A
Conditions of Sale which are available on request.
   
our warranty to be monitored.you attach proof of purchase for
.andrewswaterheaters.co.uk/registewwwour warrantyy
vements in our products which may a
o
make changes and impr
ro
vided in this document have been carefu
o
ustrations pr
ro
Conditions of Sale which are available on request.
   
our warranty to be monitored.
-a-warranty.r.andrewswaterheaters.co.uk/registe
fect the
f
ffect the
vements in our products which may a
ly prepared but
l
l
vided in this document have been carefu
       
0345 070 1057
Technical
0345 070 1055
Sales
8am - 5pm
Monday - Friday
trCustomer suppo
July 2016
                   
Andrews. Built to pe
@AndrewsWH
witter
T
Twitter
andrewswaterheaters.co.uk
ebsiteW
0345 070 1057
   
form.rAndrews. Built to pe
   
AssociationEnergy
ICOM
       