and Maxum units.
Troubleshooting (cont’d)
17
PROBLEMS
SOLUTION
POSSIBLE CAUSES
5. Timer switch 20/40/60 minute
light doesn't stay on
- loose connection
- the switch may be defective
- check connection
- replace the timer switch
4. “Wall Mount
Unit” showing
error Codes:
- Error
“E1"
-
Code
Error Code “E2"
- Error Code “E3"
- Error Code “E4"
- Error Code “E5”
- loss of communication with the Control
Board. HRV/ERV switched to OFF mode
automatically.
- defrosting Temperature Sensor Failure.
Blinks with the current operational display.
HRV/ERV does not perform defrost cycles.
- airflow Sensor Failure. Blinks with the
current operational display. HRV runs at
fixed default Low and High fans speeds.
- Humidity Sensor Failure. Blinks with the
current operational display. HRV does not
run in High Humidity mode.
- Kinked duct
- Heavy dust built on air-flow sensors
- Blinks with the current operational display.
HRV/ ERV stops fans, closes damper &
opens furnace/fan-coil/
heat pump interlock relay.
- Fans Failure.
7. All 3 LEDs of timer switch blinks - Control board reports error
- lost communication with main
control board
- refer to problem 4.
- check all wire connections on timer
switch and main control board
6. Defrost Mode does not work
- fresh air duct maybe frozen
- HRV/ERV airflow improperly
balanced
(for units without built-in
Automatic Electronic Air-balancing)
- defrost damper motor maybe
defective
- Temp. sensor maybe defective
- improper defrost cycle
- check and remove the ice
-
-
have professional balancer or
contractor balance the unit
replace the defrost motor
- replace the temp. sensor
- check defrost cycle on wall - control
and reprogram
8. No display on wall - control
- wires are shot
- loose connection
- check continuity and replace the wires
- check connections on main controller
and wall controller
- replace wall - contoller
- check wall control connections
- clean temperature sensor, if it still
shows “E2" error replace temperature
sensor
- clean dust and reinstall, if it still shows
l “E3" error replace the air flow
sensors.(supply / exhaust pair)
- replace humidity sensor
- check all ducts for blockage
- make sure all backdraft dampers on
the unit are working fine and no screws
are interfering the backdraft damper
function
-
Replace intake fan/exhaust fan
Note:-
E3 & E5 will not be displayed on
non-balancing Deluxe, Superior,
- use straight metal duct work as possible
- clean both air-flow sensors