Zehnder Rittling ComfoAir Q, Installer Manual, Page: 27 / 52

26 - EN EN - 27
8.5 Maintenance of the modulating by-pass valves
Inspect the modulating by-pass valves at least once every 4 years.
1 2 3
Remove the heat exchanger as
instructed in the maintenance
instruction of the heat exchanger:
�
Open the semi-transparent visor;
�
Change the unit to SERVICE MODE;
�
Disconnect the power to the unit;
�
Remove the 3 screws of the front
cover;
�
Remove the front cover;
�
Pull the strap of the heat exchanger.
Inspect the modulating by-pass valves
for dirt and damage. Treat any signs of dirt or damage
directly and appropriately.
Remove the modulating by-
pass valve for easy cleaning.
You can find the instructions
for removing the modulating
by-pass valve in the
chapter “How to remove the
modulating by-pass valve”.
8.6 Maintenance of the pre-heater
Inspect the pre-heater at least once every 4 years.
1 2 3
Remove the front cover as instructed
the chapter procedure for opening
the unit:
�
Open the semi-transparent visor;
�
Change the unit to SERVICE MODE;
�
Disconnect the power to the unit;
�
Remove the 3 screws of the front
cover;
�
Remove the front cover.
Pull the cable tray cover forwards. Unscrew the 2 screws of the display
cover.
Open the display cover.
4 5 6
Remove the pre-heater
communication and power cable from
the main board. Remove the pre-heater, including its
cable and grommet, from the unit. Inspect the pre-heater for dirt and
damage.
Treat any signs of dirt or damage
directly and appropriately.
Turn the pre-heater upside down and:
�
Use a soft brush to clean the fins;
�
Or use a vacuum cleaner to remove
dirt and dust.
Do not wet-clean the pre-
heater.