Replacing the main exchanger
Before carrying out the following instructions it is advisable to protect the area and the boiler's PCB housing
A
against accidental water spillage.
3
1
•
Isolate the power supply and close the Gas isolation valve to the boiler.
•
Disconnect the lead to the flue temperature sensor, Remove the sensor & save (Please fit this into the replacement
exchanger housing in readiness).
•
Disconnect the fan power lead.
•
Disconnect the white lead to the ignition electrode from the Printed Circuit board, & release the earth tag.
•
Remove the ignition electrode (2 x T15 Torx screws) Take care not to damage the gasket, replace if damaged.
•
Close ALL the isolation valves to the boiler & drain both the heating & hot water circuits down.
•
Remove the appliance flue connection (concentric or adaptor for separate ducts)
•
Remove the fan assembly (2 x 4mm Allen key bolts) Take care not to damage the cork gasket, replace if damaged.
•
Remove the 4 x spring clips "1" on the two pipes "2" to the exchanger, pump and hydraulic unit & lift away.
•
Remove the flexible connection from the top of the condense trap "4"
•
Remove the burner assembly (fig. 43) Remove the fan diaphragm & install into the new exchanger.
•
Release the clamp to the flexible gas connection (Save & re-use later)
•
Remove the 2 top screws "5" securing the exchanger to the frame (fig. 42)
•
Loosen the 2 bottom screws "5" securing the exchanger to the frame (fig. 42)
•
Remove the exchanger from the boiler casing (take care not to spill any remaining water) "6"
•
Slot the new exchanger onto the bottom screws "5"
•
Refit the Ignition electrode, Burner assembly, Fan, Condense connection, Flexible Gas connection & any removed
electrical connections
•
Fit the supplied 'O' rings to the flow & return pipes, lubricate with silicone grease (not supplied) then re-fit the pipes
& spring clips.
•
Open all isolation valves to re-fill the boiler, purge out the air, re-establish the power & test (Please follow GSIUR
26/9)
36
4
1
2
1
2
fig. 42- Main exchanger
cod. 3541P250 - Rev. 01 - 07/2018
BLUEHELIX TECH RRT 24 C
1
5
5
6
5
5
EN