39
Installation and Servicing
SECTION 3 - SERVICING
3.15 CH WATER PRESSURE SWITCH REMOVAL & REPLACEMENT
3.16 PRIMARY RETURN THERMISTOR
1.
Isolate and drain down the HIU.
Refer to Section 3.5.
2.
Remove the front panel. Refer
to Section 3.4.
3.
Unplug the electrical lead from
the thermistor.
4.
Unscrew the thermistor (to
facilitate removal a 13mm
socket spanner should be used).
5.
Fit the new thermistor using the
sealing washer provided.
6.
Reassemble in the reverse
order.
7.
Refill the HIU. Refer to Section
2.5.
8.
Check that the HIU operates in
both DHW & CH modes.
1.
Isolate and drain the HIU. Refer
to Section 3.5.
2.
Remove the front panel. Refer
to Section 3.4.
3.
Pull off the two electrical
connections.
4.
Using a suitable tool, pull out
the metal retaining clip.
5.
Carefully withdraw the pressure
switch. Check the sealing 'O'
ring is clean, undamaged and
fitted in the correct location.
6.
Fit the new pressure switch and
re-assemble in reverse order.
7.
Refill the HIU. Refer to Section
2.5.
8.
Check that the HIU operates in
both DHW & CH modes.
SER
VICING
