HAMWORTHY HEATING LTD
46
Wessex ModuMax
mk3
Boilers
500001308/C
APPENDIX E
-
WATER DATA
Model
97 /97
116/116
147/147
196/196
254/254
Water Connections (Flow & Return)
G 1½” male
G 2½” male
Maximum Water Pressure
-
bar g
-
(kPa)
10 (1000)
Water Content (litres)
-
excluding headers
16
16
22
22
22
System Design Flow Rate (litres/s) @ 11°C
Δ
T Rise
2.2
2.6
3.3
4.3
5.4
System Design Flow Rate (litres/s) @ 20°C
Δ
T Rise
1.2
1.4
1.8
2.4
3
System Design Flow Rate (litres/s) @ 30°C
Δ
T Rise
0.8
1.0
1.2
1.6
2.0
System Design Flow Rate (litres/s) @ 40°C
Δ
T Rise
0.6
0.7
0.9
1.2
1.5
Waterside Pressure Loss (mbar) @ 11°C
Δ
T Rise
61
91
500
850
1300
Waterside Pressure Loss (mbar) @ 20°C
Δ
T Rise
20
27
145
246
395
Waterside Pressure Loss (mbar) @ 30°C
Δ
T Rise
9
14
60
120
180
Waterside Pressure Loss (mbar) @ 40°C
Δ
T Rise
5
7
36
62
100
Minimum flow temperature setting
30°C @ 11°C
Δ
T
30°C @ 20°C
Δ
T
40°C @ 30°C
Δ
T
50°C @ 40°C
Δ
T
E1.1 Water Circulation System
The Wessex ModuMax boiler has a low water content and the requirements of minimum water flow are given in
the above table. Recommendations for the water circulation system are given in BS 6644 and CP 342.
The following details are of particular importance for the correct installation of the water circulation system:
1) In a combined central heating and hot water system the hot water storage vessel must be of the indirect
cylinder or calorifier type. The hot water storage vessel should be insulated, preferably with not less than 75mm
(3”) thick mineral fibre, or its thermal equivalent.
2) Circulating pipework not forming part of the useful heating surface should be insulated to help prevent heat loss
and possible freezing, particularly where pipes are run through roof spaces and ventilated cavities. Cisterns
situated in areas which may be exposed to freezing conditions should
also be insulated. Furthermore, insulation
exposed to the weather should be rendered waterproof.
3) Drain valves must be located in accessible positions which permit the draining of the whole system, including
the boiler and hot water storage vessel.
4) Each boiler module has G1½ or G2½ (refer to Table E1.1) male flow (indicated with a red spot) and return
(indicated with a blue spot) connections. Boilers should be connected by flow and return headers. Headers should
be connected to the system in a ‘reverse / return’ arrangement (the water flow in each header is in the same
direction) to ensure equal flow in each module, or with a ‘single pipe header system’. Figure E1.1.1 on the
following page show typical layouts.
5)Ideally, individual valves should be fitted to each module to enable isolation from the system, however, the
arrangement must comply with the requirements of BS 6644.
Table E1.1—Water Data
