Alpha Alpha CB50 Boiler Parts list manual

Instructions for replacing the electrically
operated automatic flow regulator with
the mechanical flow regulator valve
Alpha CB50 Boiler
1. GENERAL
Ensure that the following instructions are carried out before replacement begins.
a. Isolate the electrical and gas supplies to the boiler and turn off the mains water supply.
b. Gain access behind the case and to the PCB as described in the Installation and Servicing instructions.
c. Connect a hose to the cylinder drain valve and drain the cylinder to outside.
2. REMOVETHE ELECTRICALLY OPERATED FLOW REGULATOR
a. Disconnect the flow regulator plug and socket located within the PCB enclosure. Unplug the wiring connectors
M1 and M13 from the PCB, see Fig. 2.
b. Remove the two white wires from the connectors M1 and M13. This can be achieved by pressing the tab in the
side of the plug and at the same time pulling the wire from its socket, see Fig. 2.
c. Remove the regulator's thermostat (located behind the DHW expansion vessel) and cable by removing the lower
front right hand side casing screw and sliding the thermostat to the right, releasing it from the retaining clip on the
cylinder, see Fig. 3.
d. Replace the connectors M1 and M13 into position on the PCB and re-assemble the control panel rear cover.
e. Secure the right hand side casing panel with the screw previously removed.
f. Disconnect the mains inlet valve and cylinder union connections from the regulator valve and remove the
regulator. Remove the filter from the regulator and retain, see Fig. 4.
NOTE: All parts removed must be returned to Alpha detailing the CB50 boiler serial number which is located
on the hinged control panel cover.
Fig. 1 - Kit Contents
Union bend (A)

Fig. 2
Fig. 3
Flow
regulator
thermostat
DHW
expansion
vessel

07/04/D163
Fig. 4 - CB50 fitted with flow regulator on inlet
Fig. 5 - CB50 fitted with new type flow regulator on outlet
3. FIT THE MECHANICAL FLOW VALVE
a. Fit the union bend (A in Fig. 1) supplied, in the position where the regulator was removed from using the new
washers supplied, see Fig. 5.
Note: Before fitting the union bend, position the filter (previously removed from the regulator) into the manifold, see Fig. 5.
b. Remove the DHW outlet pipe by offering the new flow valve and pipe assembly supplied, upto the DHW outlet pipe
and mark where the existing pipework needs to be cut. Cut the pipe and remove it from the cylinder.
c. Fit the new valve and outlet pipe assembly to the cylinder and DHW pipework using the new washers supplied, see Fig 5.
d. Turn on the electrical, gas and water supplies, refill the cylinder and test the operation of the new valve.
e. Re-assemble all the remaining parts to complete re-assembly of the boiler.
Compiled and designed by Publications 2000, Tel [phone]
These guidelines have been carefully prepared but we reserve the right to
alter the specification at any time in the interest of product improvement.
© Alpha Therm Limited 2004.
Alpha Therm Limited.
NepicarHouse,LondonRoad,WrothamHeath,
Sevenoaks, Kent TN15 7RS
Technical Helpline: 0870 3001964
email: [e-mail]
website: www.alpha-innovation.co.uk