WarmFlow Utility Combi UC70HEE - 14 Combi Fault Finding; Central Heating

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10.1.6 Frost Protection
Where there is a risk to the boiler or installation from frost then a suitable frost thermostat
should be fitted. Alternatively the system could be dosed with an antifreeze agent. The
Kabin Pak Combi boiler is factory fitted with a frost thermostat as standard to protect the
fabric of the boiler only. For all other Kabin Pak models covered by this manual a Frost
Thermostat Kit (Code FSK1) is available as an optional extra. This also protects the fabric
of the boiler only. Details of frost protection for the fabric of the building can be found in
section 6.3.3 of this manual.
10.1.7 Pipework
We strongly advise that all installation pipework is run in copper. However, if plastic pipe is
used, it must be recommended by the pipe manufacturer for use with oil fired appliances
and, in any case, the last 1000mm of pipework connected directly to the appliance must be
of copper. All connections to the appliance must be made with compression fittings.
10.2 Sealed Systems
10.2.1 Expansion Vessel
Refer to Section 4.2 of this manual for standards referencing details of expansion vessel
sizing.
The values given in the table below are for total system volumes which include the water
content of the boiler details of which can be found in the Technical Data Section 5.4 of this
manual. System and Combi models up to 120HE are supplied with a 12 litre expansion
vessel charged to 1.0 bar. This can accommodate a maximum combined boiler and system
volume of 110 litres. Where permitted by the type, size and configuration of heating system
the expansion vessel bladder pre-charge pressure can be reduced, prior to filling the
system, to 0.5 bar in order to accommodate a total system volume of 145 litres. Expansion
vessel pre-charge pressures should be evaluated and adjusted periodically, normally as
part of servicing.
When measuring the expansion vessel bladder pre-charge pressure, using a tyre gauge,
the system should be cold and the system pressure should be relieved (by manually
operating the system pressure relief valve) in order to obtain an accurate reading.
If the maximum total system volumes stated above are to be exceeded, additional
expansion capacity will be required.
INITIAL
CHARGE
VESSEL VOLUMES
0.5
2.1
4.2
6.3
8.3
10.5
12.5
14.6
16.7
18.7
20.8
22.9
25.0
1.0
2.7
5.4
8.2
10.9
13.6
16.3
19.1
21.8
24.5
27.2
30.0
32.7
1.5
2.9
7.8
11.7
15.6
19.5
23.4
27.3
31.2
35.1
39.0
42.9
46.8
SYSTEM
VOLUME
25
50
75
100
125
150
175
200
225
250
275
300
Do not allow the flexible hoses connected to the expansion vessel to become twisted,
kinked or flattened. This may cause collapse of hose bore compromising the function of the
expansion vessel.