Troubleshooting - Fantech VHR 704 Manuel D'installation

Troubleshooting

Problem
Air is too dry
Air is too humid
Persistent condensation
on window
Poor Air Flows
Supply air feels cold
HRV and/or Ducts frosting up
Condensation or Ice Build Up in
Insulated Duct to the Outside
Green LED Light Codes on
Control Board
Constant Flash
Light is ON, and not Flashing
Light is OFF, and not Flashing
Note: It is best to get the unit checked by a certified HVAC Contractor/Technician.
Causes
Dehumidistat control is set too low
HRV out of balance
Dehumidistat control is set too high
Sudden change in temperature
Storing too much wood for heating
Dryer vent exhaust is inside home
Poor air circulation near windows
HRV out of balance
Well sealed basement door is closed
Failed damper system may be stuck in recirculation
mode
Improper adjustment of dehumidistat control
HRV out of balance
Poor air circulation near windows
1/4" (6mm) mesh on the outside hoods is plugged
Filters plugged
Core obstructed
Indoor grilles closed or blocked
Inadequate power supply at site
Ductwork is restricting airflow
Improper speed control setting
HRV airflow improperly balanced
Ducting has fallen down or been disconnected from HRV
Poor location of supply grilles, the airflow may irritate
the occupant
Outdoor temperature extremely cold
HRV air flows are improperly balanced
Malfunction of the HRV defrost system
Incomplete vapor barrier around insulated duct
A hole or tear in outer duct covering
Everything is in good operations
Control Board is defective
No Power is being transmitted to the Control Board
Solutions
Increase the desired level of humidity. Change ventilation mode from
continuous mode to standby.
Have contractor balance HRV airflows
Reduce the desired level of humidity. Combine this with the use of continuous
exchange mode.
Wait until outside temperature stabilizes (winter). Heating will also improve
situation.
Store a majority of your wood outside. Even dried, a cord of wood contains
more than 20 gallons of water.
Make sure the dryer vent is exhausting outside.
Open curtains or blinds.
Have contractor balance HRV airflows
Open the door or install a grill on the door.
Check defrost damper. If damper is always blocking incoming fresh air, have
contractor verify damper system.
Reduce the desired level of humidity. Combine this step with use of continuous
exchange mode.
Have contractor balance HRV
Open curtains or blinds.
Clean exterior hoods or vents
Remove and clean filter
Remove and clean core
Check and open grilles
Have electrician check supply voltage
Check duct installation
Increase the speed of the HRV (i.e. change unit control from LOW to MED speed)
Have contractor balance HRV airflows
Have contractor reconnect ducting
Locate the grilles high on the walls or under the baseboards, install ceiling
mounted diffuser or grilles so as not to directly spill the supply air on the
occupant (eg. Over a sofa)
Turn down the HRV supply speed. A small duct heater (1kw) could 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
Have HVAC contractor balance the HRV airflows
Note: minimal frost build-up is expected on cores before unit initiates defrost
cycle functions
Tape and seal all joints
Tape any holes or tears made in the outer duct covering
Ensure that the vapor barrier is completely sealed.
Replace Control Board
Make sure unit is plugged.
Transformer may need replacing.
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