Alpha CD13R Installation And Servicing Instructions page 10

3.9 FILLING THE SEALED CENTRAL HEATING SYSTEM - Figs. 6, 7
The system design pressure (cold) should be set to 1.0 bar. This pressure is equivalent to a static head (see Fig. 5) of 10.2 metres of water.
Provision should be made to replace water lost from the system. This can be by manual or automatic means, as shown in Figs.
6 and 7. The position for connecting an automatic make-up vessel is indicated in Fig. 5a. A double check valve assembly must
be used, as shown in Fig. 7.
Filling of the system must be carried out in a manner approved by the local Water Undertaking. Where allowed, the system
may be filled via a temporary connection as shown in Fig. 6. After filling, always disconnect the flexible hose of the filling loop.
All fittings used in the system must be able to withstand pressures up to 3 bar.
Drain taps (to BS 2879) must be used to allow the system to be completely drained.
Hose
unions
Heating circuit
return
Stop
valve
Filling loop
temporarily connected
Fig. 6
3.10 FLUSHING THE HEATING SYSTEM
It is essential that the central heating system is thoroughly cleaned and flushed when fitting an Alpha CD boiler. Failure to do so
will invalidate the warranty.
The primary and condensing heat exchanger is constructed in stainless steel and therefore is compatible with most materials
used in a heating system.
If a cleaning agent and inhibitor are used, they must be applied in accordance with their manufacturers instructions. Only
products from Fernox and Sentinel are acceptable for use with the Alpha CD boilers. Further information can be obtained from
Fernox (Tel: 0179 9521133) or Sentinel (Tel: 0151 4209563).
The system should be flushed in accordance with BS 7593 and BS 5449. The following procedures are recommended:
1. Installing onto a new system:-
a. Fill the system, vent at high points, at pump and radiators.
b. Check for leaks.
c. Rapidly drain the system.
d. If required, chemically clean the system as instructed by the recommended cleaner manufacturer.
Note: Ensure that the system is flushed to remove any remains of the cleaner.
e. If chemical cleaner is not used to clean the system:-
i) Refill the system.
ii) Switch on the boiler and allow the system to heat up to the normal operating temperature.
iii) Rapidly drain the system while the water is still hot.
iv) Refill the system.
f. As required, add the recommended inhibitor to the system as instructed by the inhibitor manufacturer.
g. Recheck for leaks.
2. Installing onto an existing system, clean the system before fitting the new boiler:-
a. If the old boiler is still working:-
i) Switch on the boiler and allow the system to heat up to the normal operating temperature.
ii) Rapidly drain the system while the water is still hot.
iii) Refill and chemically clean the system as instructed by the recommended cleaner manufacturer.
iv) Ensure the system is flushed to remove any remains of the cleaner.
v) Fit the new boiler.
b. If the old boiler is not working:-
i) Rapidly drain the system.
ii) Remove the old boiler.
iii) Flush the system through.
iv) Fit the new boiler.
v) Refill and chemically clean the system as instructed by the recommended cleaner manufacturer.
vi) Ensure the system is flushed to remove any remains of the cleaner.
c. As required, add the recommended inhibitor to the system as instructed by the inhibitor manufacturer.
d. Check for leaks.
Alpha CD13R, 18R, 24R - General Boiler Information
10
Double check
valve assembly
Mains
water
Stop supply
valve
Test cock
Double check
valve assembly
Heating circuit
return
Test cock
Overflow
Feed cistern to be
located above highest
Stop
point in the system
valve
Fig. 7
Mains
water
supply