Glow-worm Ultracom 24cxi Installation And Servicing page 62

15.26 Hydroblock and Bypass Tube
For access, refer to section 15.1.
IMPORTANT: To replace the bypass tube and seals the LH
and RH hydroblocks will need to be removed. The following
procedure must also be used for the replacement of either the
LH or RH hydroblock.
Refer to section 15.1 and drain the boiler heating circuit and
the boiler domestic water circuit.
CH FLOW
(from heat
exchanger)
62
15 Replacement of Parts
Diagram 15.19
LH HYDROBLOCK
DHW OUTLET
RETAINING CLIP
MOUNTING
RETAINING
BRACKET
CLIP
FILTER
(in Hydroblock)
Disconnect the CH flow, return and DHW inlet pipes at the
bulkhead connectors, then the retaining clips, remove the
pipes and "o" ring seals.
Remove the low water pressure sensor as described in
section 15.21.
Remove the flow sensor as described in section 15.22.
Remove the 3 way valve as described in section 15.24.
Remove the pump as described in section 15.17.
Remove the plate to plate heat exchanger, refer to section
15.25.
Disconnect the central heating flow at the heat exchanger
connector then remove the retaining clip at the hydroblock.
Disconnect the pipe and "O" ring.
Remove clips from the plastic LH and RH hydroblocks
retaining the DHW, DCW and heating flow pipes, see diagram
15.20.
Remove the CH filter from the heating flow pipe port in the LH
hydroblock. The filter is a push-fit in the hydroblock port.
Grip the LH and RH hydroblocks simultaneously and lift clear
of the spigots on the mounting bracket.
NOTE: Before removing the bypass tube from the
hydroblocks, take note of the tube position and orientation.
Fit the new bypass tube with new 'O' ring seals and re-
assemble to hydroblocks.
Before refitting the plate to plate heat exchanger ensure that
the four rubber seals are in place, two in the LH and two in the
RH hydroblock.
Fit new 'O' rings to pipes.
Refill system, vent and pressurise the boiler.
PLATE TO PLATE
RUBBER SEAL
RH HYDROBLOCK
(4 OFF)
DCW INLET
RETAINING CLIP
BYPASS
TUBE
DCW INLET
DHW OUTLET
CH FLOW
SPIGOT (4 OFF)
3 WAY VALVE SEALS
Diagram 15.20