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SYMPTOM CAUSE SOLUTION
PoorAir Flows
Supplyair feels cold
Dehumidistatis not Operating
HumidityLevels are too High
Condensationis appearing on the windows
HumidityLevels are too Low
HRVand/or Ducts Frosting up
Condensation or Ice Build Up in Insulated
Ductto the Outside
Waterin the bottom of the HRV
•1/4” (6 mm) mesh on the outside hoods is plugged
•filters plugged
•core obstructed
•house grilles closed or blocked
•dampers are closedif installed
•poor power supply at site
•ductwork isrestricting HRV
•improper speed controlsetting
•HRV airflowimproperly balanced
•poor location of supply grilles, the airflow may irritate
theoccupant
•outdoor temperatureextremely cold
•outdoor temperatureis above 15°C (59°F)
•improper low voltageconnection
•external low voltage is shortened out by a staple or nail
•check dehumidistat setting it may be on OFF
•dehumidistat is set toohigh
•HRV is undersizedto handle a hot tub, indoor pool, etc.
•lifestyle of the occupants
•moisture coming into the home from an unvented or
unheatedcrawl space
•moisture is remaining in the washroom and kitchen areas
•condensation seems toform in thespring andfall
•HRV is set at too low a speed
•dehumidistat control set too low
•blower speed of HRV is toohigh
•lifestyle of occupants
•HRV air flows may be improperly balanced
•HRV airflows are improperly balanced
•malfunction of the HRV defrost system
•incomplete vapour barrier around insulated duct
•a hole or tearin outerduct covering
•drain pans plugged
•improper connection of HRV’s drain lines
•HRV is not level
•drain lines areobstructed
•HRV heat exchange core is not properly installed
•clean exteriorhoods or vents
•remove and clean filter
•remove and clean core
•check and open grilles
•open and adjustdampers
•have electrician check supply voltage at house
•check duct installation
•increase the speed of the HRV
•have contractorbalance HRV
•locate the grilles high on the walls or under the baseboards,
installceiling mounted diffuser or grilles so as not to directly
spillthe supply air on the occupant (eg. over a sofa)
•turn down theHRV supplyspeed. A smallduct heater
(1kw)could be used to temper the supply air
•placement offurniture or closeddoors is restrictingthe
movementof air in the home
•if supplyair is ductedinto furnace return, the furnace fan
mayneed to run continuously to distribute ventilation
aircomfortably
• dehumidistat is functioning normally (see “How the
DehumidistatWorks” in this manual)
•check that the correct terminals have been used
•check external wiring for a short
•set thedehumidistat at the desired setting
•set dehumidistatlower
•cover pools, hot tubs when they are not in use
•avoid hangingclothes to dry, storingwood andventing clothes
dryerinside.Heating wood may have to be movedoutside
•vent crawl space and place a vapour barrier on the floor
ofthe crawl space
•ducts from the washroom should be sized to remove moist
airas effectively as possible, use of a bathroom fan for
short periods will remove additional moisture
•on humid days, as the seasons change,some condensation
mayappear but the homes air qualitywill remain high with
someHRV use
•increase speed ofthe HRV
•set dehumidistathigher
•decrease HRV blowerspeed
•humidity may have to be addedthrough the use of humidifiers
•have a contractorbalance HRV airflows
•Note: minimal frost build-up is expected on cores before
unitinitiates defrost cycle functions
•have HVAC contractor balance the HRV
•ensure damperdefrost is operating during self-test
•tape and sealall joints
•tape any holes or tears made in the outer duct covering
•ensure that the vapourbarrier is completely sealed
•ensure O-Ring on drain nozzle sits properly
•look for kinks in line
•check waterdrain connections
•make sure water drains properly from pan
Troubleshooting your HRV/ERV System