Potterton Ultra 2, Installation & Service Instructions Manual

Page: 42 / 59

Replacement of Parts - Page 42
6.8 Pressure Relief Valve
1. Gain General Access - See Section 6.1, Paragraph 1.
2. Drain the system by removing the pressure gauge
connection from the water manifold.
Note: When the system is drained, filled or vented, the
manual lever on the left hand side of the diverter valve
must be moved to the 'MID' (manual override) position.
Return it to its original position after the system has
been filled and vented.
3. Disconnect the compression joint securing the
discharge pipe to the valve.
4. Remove the two grub screws (top & bottom) that
secure the valve to the water manifold then remove the
valve.
5. Fit the new valve and a new 'O' ring. Use a soap
solution as a lubricant.
6. Re-assemble in reverse order.
6.9 By-Pass Valve
1. Gain General Access - See Section 6.1, Paragraph 1.
2. Drain the system by removing the pressure gauge
connection from the water manifold.
Note: When the system is drained, filled or vented, the
manual lever on the left hand side of the diverter valve
must be moved to the 'MID' (manual override) position.
Return it to its original position after the system has
been filled and vented.
3. Release the two unions securing the valve to the water
manifold and by-pass pipe. Remove the valve.
4. Fit the new valve, use a new washer at the connection
with the water manifold and check the condition of the
olive at the connection with the by-pass pipe.
Note: The spare by-pass valve is pre-set and must not
be adjusted.
5. Fill and vent the boiler as described in Section 2.13.
Check the unions for water soundness.
6. Re-assemble in reverse order.