12
TROUBLESHOOTING
See Table 2 for troubleshooting.
Table 2 — Troubleshooting
LEGEND
PROBLEM
CAUSE
SOLUTION
Air is Too Dry
Dehumidistat control is set too low.
Increase the desired level of humidity. Change
ventilation mode from continuous mode to
standby.
HRV out of balance.
Balance HRV.
Air is Too Humid
Dehumidistat control is set too high.
Reduce the desired level of humidity. Use
continuous exchange mode.
Sudden change in temperature.
Wait until outside temperature stabilizes
(winter). Heating will also improve humidity of
air.
Storing too much wood for heating.
Store majority of wood outside. Even dried, a
cord of wood contains more than 20 gallons of
water.
Dryer vent exhaust is inside home.
Arrange outside vent for dryer.
Poor air circulation near windows.
Open curtains or blinds. Bay or bow windows
may require additional air circulation.
HRV out of balance.
Balance HRV.
Basement door is closed.
Open the door or install a grille on the door.
Air is Too Dry
Dehumidistat control set too low.
Increase the desired level of humidity. Change
ventilation mode from continuous to standby.
HRV out of balance.
Balance HRV.
Persistent Condensation
on Window
Improper adjustment of dehumidistat control.
Reduce the desired level of humidity. Use con-
tinuous exchange mode.
HRV out of balance.
Balance HRV.
Poor Airflow
1
/
4
-in. mesh on the outside hoods is plugged.
Clean exterior hoods or vents.
Filters plugged.
Remove and clean filter.
Core obstructed.
Remove and clean core.
House grilles closed or blocked.
Check and open grilles.
Dampers are closed if installed.
Check and open dampers.
Poor power supply at site.
Have electrician check supply voltage at
house.
Ductwork is restricting HRV operation.
Check duct installation.
Improper speed control setting.
Increase the speed of the HRV.
HRV airflow improperly balanced.
Have contractor balance HRV.
Supply Air Feels Cold
Poor location of supply grilles. Airflow may
irritate the occupant.
Locate the grilles high on the walls or under the
baseboards. Install ceiling mounted diffuser or
grilles so as not to directly vent the supply air
on the occupant.
Turn down the HRV supply speed.
Outdoor temperature extremely cold.
A small duct heater (1 kW) can be used to
temper the supply air.
Placement of furniture or closed doors is
restricting the movement of air in the home.
If supply air is ducted into furnace return, the
furnace fan may need to run continuously to
distribute ventilation air comfortably.
ERV and/or Ducts Frosting Up
HRV air flows are improperly balanced.
Minimal frost build-up is expected on cores
before unit initiates defrost cycle functions.
Balance airflow if needed.
Malfunction of the HRV defrost system.
Have HVAC contractor check the HRV.
Condensation or Ice Build-Up in Insulated Duct
to the Outside
Incomplete vapor barrier around insulated
duct.
Tape and seal all joints. Ensure that the vapor
barrier is completely sealed.
Hole or tear in outer duct covering.
Tape any holes or tears made in the outer duct
covering. Ensure that the vapor barrier is com-
pletely sealed.
HRV
—
Heat Recovery Ventilator
HVAC —
Heating, Ventilation and Air Conditioning
