Glow-worm Betacom C - Manual (Page 15)

15
Diagram 5.3
Diagram 5.2
14024
14562
5.10 Water Pressure
To obtain the best hot water performance from your boiler it is
suggested that the cold water supply to the boiler is the first
draw off from the incoming mains supply.
NOTE: The boiler will not operate unless there is a minimum
pressure of 0.25 bar (3.6 Ibf/in 2 ) with a flow rate of 2.5 l/min.
The minimum working pressure to obtain the maximum
domestic flow is:-
24c 0.7 bar (10.15 Ibf/in 2 )
30c 0.7 bar (10.15 Ibf/in 2 )
The maximum working pressure of the domestic hot water
circuit is 8 bar. If the cold water supply pressure exceeds this,
then a pressure-reducing valve must be fitted in the supply to
the boiler.
Where cold water mains are fitted with a water meter, check
valve(s) or loose jumper stopcock, a domestic hot water mini-
expansion vessel may need to be fitted.
To obtain the best hot water performance from your boiler it is
suggested that supplies to faucets are run in 15mm copper,
as short as possible and where practical, be insulated to
reduce heat loss.
5.11 ‘Hard’ Water Areas
The temperatures within the heat exchanger are limited by
the boiler control system to minimise scale formation within
the hot water pipework. However, in areas where the water is
‘hard’ (i.e. more than 200mg/litre), it is recommended that the
hot water setting is reduced and that a scale reducer is fitted,
refer to the manufacturer’s instructions or consult the local
water company for additional advice.
5 Water System - Domestic Hot Water
7
6
5
4
3
2
1
0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
H (m)
Q (m 3 /h)
QH Chart