System Requirements - Central Heating - Ideal Heating LOGIC+ SYSTEM S18 Installation & Servicing

1.18 SYSTEM REQUIREMENTS - CENTRAL HEATING

Notes
a. The method of filling, refilling, topping up or flushing sealed circuits
from the mains supply must be done in accordance with national and
local regulations ie: proper backflow prevention must be in place.
b. Antifreeze fluid, corrosion and scale inhibitor fluids suitable for use
with boilers having aluminium heat exchangers may be used in the
central heating system.
c. The use of suitable inhibitor fluids is mandatory. For boiler
changeovers on existing systems all existing system components
must be thoroughly flushed with appropriate chemicals/power flush
pumps prior to installing the new boiler. Failure to adhere to either
of the above will void boiler warranty as per T&C's.
d. The use of the correct gas isolation valve is mandatory.
General
1. The installation must comply with all relevant national and local
regulations.
2. The installation should be designed to work with flow
temperatures of up to 86 C.
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3. All components of the system must be suitable for a working
pressure of 300kPa and a maximum design temperature of 110
C. Extra care should be taken in making all connections so that
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the risk of leakage is minimised.
The following components are incorporated within the appliance:
a. Circulating pump.
b. Safety valve, with a non-adjustable preset lift pressure of
300kPa.
c. Pressure gauge, covering a range of 0 to 400kPa.
d. An 8-litre expansion vessel, with an initial charge pressure
of 75kPa.
4. Filling Water Connection. Mains water fill lines must be
installed with an Automatic Filling Valve - Available from
Hunt Heating. After following the below filling instructions the
Automatic Filling Valve MUST be turned off.
The maximum cold water capacity of the system should not
exceed 143 litres. This is the maximum system volume for
the boiler expansion vessel. If the capacity of the vessel is
not considered sufficient for this, or for any other reason, an
additional vessel MUST be installed on the return to the boiler.
Guidance on vessel sizing is given in table opposite.
5. Filling
After installation of an Autofill valve and required backflow
prevention, the system may be filled by the following method:
i. Thoroughly flush out the whole system with cold water.
ii. Fill and vent the system until the pressure gauge registers
150kPa, and examine for leaks.
iii. Check the operation of the safety valve by raising the water
pressure until the valve lifts. This should occur within 30kPa of
the preset lift pressure.
iv. Release water from the system until it reaches 100kPa.
Isolate main water supply by turning off autofill valve.
Installation and Servicing
SECTION 1 - GENERAL
Safety valve setting
Vessel charge pressure
System pre-charge pressure kPa
For other system volumes
multiply by the factor across
kPa
kPa
System volume
(litres)
25
50
75
100
125
150
175
190
200
250
300
Model
Max CH Output kW
Water flow rate l/min
(gal/min)
Temp differential C
o
Head available kPa
for system (ft.w.g.) (14.7)
300
50 to 75
None 100
Expansion vessel
volume (litres)
1.6 1.8
3.1 3.7
4.7 5.5
6.3 7.4
7.8 9.2
9.4 11.0
10.9 12.9
11.9 14.0
12.5 14.7
15.6 18.4
18.8 22.1
0.063 0.074
18 30
18 30.3
13 21.5
(2.8) (4.7)
20 20
44.12 18.63
(6.2)
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