Residential HRV/ERV
40
Symptom Possible Causes Solution
HRV does not power
up (indicator light on
the unit is not lit up)
• Unit is not plugged in
• No power to outlet
• Defecve fuse
• HRV control board may be defecve
• Make sure unit is plugged in
• Test outlet with another device
HRV is not
responding to a wall
control
• Wall control is set to OFF.
• Terminal block is loose.
• Bad low voltage connecon or
interrupon (due to a nail in the wall,
for example).
• Ensure that the wall control has power
(screen or LED lights illuminate).
• Check wiring from HRV to wall control for
open/short circuit.
• Ensure that the terminal block is well seated
in the HRV
The HRV is producing
excessive vibraons
• Dirt on the fan wheels
• Malfunconing motor
• Call contractor to perform HRV servicing
Poor airows • Hoods or grilles are obstructed
• The HRV lters are clogged
• Obstrucon in the heat-recovery core
• Poor power supply
• Ductwork is restricng airow to/
from HRV
• Speed is set to Low
• HRV is not balanced.
• Ensure that the outdoor exhaust and intake
hoods are free of obstrucons
• Clean or replace the lters
• Clean the heat-recovery core
• Use wall control to increase the speed of
the HRV
• Call your contractor to check supply voltage
and/or balance the HRV airows.
Supply air feels cold • Outdoor temperature is extremely
cold.
• Supply grille is located close to
occupants
• HRV automac defrost funcon is
not working
• Locate the supply grilles high on the walls,
or in the ceiling with a diuser.
• Reduce the operang speed of the HRV
• Install a small duct heater (1 kW) behind the
supply grille.
• If supply air is ducted through the furnace
plenum, ensure that the HRV and furnace
fan are interlocked.
Wall Dehumidistat is
not working
• The wall control is not set properly
• Outdoor RH is higher than the
control setpoint
• Bad low voltage connecon or
interrupon (due to a nail in the wall,
for example).
• For control 611224, ensure that knob is
turned to a lower setpoint than outdoor RH.
• For control 611242-FC, ensure that the
AUTO mode is selected and the target RH
level is below the outdoor RH.
• For control 611227, ensure the wall control
is not OFF and that the target RH setpoint is
below the outdoor RH.
• Check wiring from HRV to wall control for
open/short circuit.
TROUBLESHOOTING