Domestic Hot Water System Design; Boiler Schematic - Saunier Duval ISOFAST F 28 E Installation And Operating Instructions Manual

DOMESTIC HOT WATER SYSTEM DESIGN

Copper tubing or plastic hep20 may be used for the
domestic hot water system. Unnecessary pressure losses
should be avoided.
A flow restrictor limiting the flow through the boiler
to a maximum of 12 l/min is fitted to the boiler.
The boiler will operate with a minimum supply

BOILER SCHEMATIC

1 - Domestic thermistor
2 - Three way valve
3 - Gas valve
4 - Gas valve ignition module
5 - Heating element
6 - Micro accumulation vessel
7 - Burner
8 - Ignition electrode
9 - Combustion chamber
1 0 - Micro accumulation vessel thermistor
1 1 - Main heat exchanger
1 2 - Air pressure switch
1 3 - Heating safety valve (3 bar)
1 4 - Electronic control (PCB)
1 5 - Domestic water flow sensor
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21
22
20
19
18
17
16
15
14
25
13
Diagram 6
8
pressure of 0,7 bar, but under reduced flow rate. Best
operating comfort will be obtained from a supply pres-
sure of 1 bar.
'Hard Water Areas'
In areas where the water is 'hard', more than 200mg/
litre, it is recommended that a proprietary scale reducer
is fitted in the cold water supply to the boiler.
1 6 - Bypass
1 7 - Domestic heat exchanger
1 8 - Pump
1 9 - Expansion vessel
2 0 - Heating thermistor
2 1 - Overheat safety thermostat
2 2 - Flame sense electrode
2 3 - Fan
2 4 - Domestic safety valve
2 5 - Loss of water sensor
A - Heating return
B - Cold water inlet
C - Heating flow
D - Domestic hot water outlet
E - G a s
A B C D F
12
11
10
9
8
7
6
5
4
3
2
1
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