Sight Glass; Water Temperature Sensor; Dry Fire Temperature Sensor; Case Temperature Sensor - Potterton Envoy System 30 Installation & Service Instructions Manual

Servicing & Replacement of Parts - Page 22
Fig.21
10) Sight Glass (combustion chamber or case
door).
Note: Care should be taken when handling and
disposing of broken glass.
a) Remove decorative casing door if changing functional
door sight glass or both decorative and functional doors
if changing combustion chamber sight glass, as
described in 'Servicing Boiler'.
b) Remove two screws retaining sight glass assembly and
carefully remove from the combustion chamber or door.
c) Replacement is the reverse of removal ensuring a new
gasket is fitted either side of the glass.
11) Water Temperature Sensor (flow and
return).
a) Remove decorative and functional doors as described in
'Servicing Boiler'.
b) Disconnect two leads from the sensor and remove it by
gently squeezing two protruding plastic lugs and while
still squeezing pull from its housing.
c) Replacement is the reverse of removal ensure when
fitting new sensor that sensor tip is coated with heat
conducting paste and that it is correctly located and
firmly home in its housing.
22 Servicing & Replacement of Parts
Supplied By www.heating spares.co Tel. 0161 620 6677

12) Dry Fire Temperature Sensor.

a) Remove decorative and functional doors as described in
'Servicing Boiler'.
b) Disconnect two grey leads from the sensor.
c) Remove retaining screw and gently pull sensor from the
heat exchanger.
d) Replacement is the reverse of removal. Ensure that the
sensor tip is coated with conductive paste and correctly
located in its housing.

13) Case Temperature Sensor.

a) Remove decorative and functional doors as described in
'Servicing Boiler'.
b) Disconnect two yellow leads from the sensor.
c) Remove fixing screw from mounting bracket.
d) Remove sensor
e) Replacement is the reverse of removal.
Publication No. 559787