Troubleshooting - Greenheck ASSURE-120S-S1 Installation, Operation And Maintenance Manual

Troubleshooting

Symptom
Poor airflow(s)
Supply air feels cold
Dehumidistat is not operating
Humidity levels are too high; condensation is
appearing on windows
Humidity levels are too low
ERV units and/or ducts frosting up
Condensation or ice build−up in insulated duct to
the outside
Water in the bottom of the ERV unit
32 Residential Energy Recovery Ventilators
Table 16. Troubleshooting
Cause
• Mesh on outside hoods plugged
• Filters plugged
• Core obstructed
• House grilles closed or blocked
• Dampers closed (if installed)
• Poor power supply at site
• Ductwork is restricting ERV
• Improper speed control setting
• ERV airflow improperly balanced
• Poor location of supply grilles
• Airflow may irritate occupants
• Outdoor temperature extremely cold
• Outdoor temperature is above 59
• Improper low−voltage connection
• External low voltage is shorted out by a staple
or nail
• Check dehumidistat setting; it may be OFF
• Dehumidistat set too high
• ERV unit is undersized to handle a hot tub,
indoor pool, etc. (Occupant Lifestyle)
• Moisture coming into the home from an non-
vented or non-heated crawl space
• Moisture remaining in washroom and/or
kitchen areas
• Condensation seems to form in the spring and
fall seasons
• ERV is set at too low a speed
• Dehumidistat control set too low
• Blower speed of ERV is too high
• Occupant lifestyle issue
• ERV airflows may be improperly balanced
• ERV air flows are improperly balanced
• Malfunction of the ERV defrost system
• Incomplete vapor barrier around insulated
duct
• Hole or tear in outer duct covering
• Drain pans plugged
• Improper connection of ERV drain lines
• ERV is not level
• Drain lines obstructed
• ERV heat exchange core is not properly
installed
Solution
• Clean exterior hoods or vents
• Remove and clean both filter and core
• If unit is equipped with MERV 13 filters,
replace every 3 months.
• Check and open grilles
• Open and adjust dampers
• Have electrician check supply voltage at
house
• Check duct installation
• Increase the speed of the ERV
• Have contractor balance the ERV
• Locate the grilles high on the walls or under
the baseboards
• Install ceiling mounted diffuser or grilles so as
not to direct airflow onto occupants (e.g. over
a couch)
• Turn down the ERV supply speed
• A small duct heater (1kw) could be used to
temper the supply air
• Placement of furniture or closed doors
restricting movement of air in home; consider
rearranging
• If supply air is ducted into furnace return, the
furnace fan may need to run continuously to
distribute ventilation air comfortably
• Dehumidistat is functioning normally (see
º º
F (15 C)
"Dehumidistat Disable" on page 10)
• Check that the correct terminals have been
used
• Check external wiring for a short
• Set the dehumidistat at the desired level
• Set dehumidistat at lower level
• Cover pool or hot tub when not in use
• Avoid hanging clothes to dry indoors, storing
wood indoors, and venting dryer inside
• Vent crawl space and place a vapor barrier on
the floor of the crawl space
• Ducts from washroom should be sized to
remove moist air as effectively as possible;
use of a bathroom fan for short periods will
remove additional moisture
• On humid days, as seasons change, some
condensation may appear but the home's air
quality will remain high with some ERV use
• Increase speed of ERV
• Set dehumidistat at higher level.
• Decrease ERV blower speed
• Humidity may have to be added through use
of humidifiers
• Have a contractor balance ERV airflows
• NOTE: Minimal frost build-up is expected on
cores before unit initiates defrost cycle.
• Have HVAC contractor balance the ERV
airflows
• Ensure damper defrost is operating during
self−test
• Tape and seal all joints
• Tape any holes or tears made in the outer
duct covering
• Ensure that the vapor barrier is complete
sealed
• Look for kinks in the drain line
• Check water drain connections
• Make sure water drains properly from pan(s)
®