Airmax MaxAir 100 LV, Installation And Maintenance Instructions Manual

Page: 30 / 48

Page 30
TROUBLESHOOTING .
external pump does not run
In areas where hard water is present the
pump may “stick” and fail to run after long
idle periods. Often this can be freed by
closing the isolation valve on the return leg
and opening the drain port so full city water
pressure flows through the pump. If this fails
to free the pump, removal for cleaning or
replacement is necessary.
external pump is noisy at start-up
Air is present in heating loop. If sound has
not diminished within 1 minute, purge air in
accordance with the
Start-Up procedures.
Check to make sure branch connections for
heating loop are horizontal.
water heater T&P is weeping
A check valve or back-flow preventor has
been installed in the system. Some form of
pressure relief may be required.
Options are:

Install expansion tank.

Install pressure relief valve; locate outlet
over laundry tub or floor drain.
Install combination toilet tank/pressure relief
valve
insufficient or no heat

Plugged air filter or coil. Refer to
Maintenance section for filter care and
coil cleaning.

Air in heating loop; purge system.

Inlet and outlet connections to air handler
backwards; reverse connections.

Restricted or improperly installed supply
tube in water heater; check and replace.

Water heater thermostat set too low or
not calibrated properly; check water
temperature at a faucet. If the
temperature has been set low because of
homeowner preference, an anti-scald
valve may be needed to provide the
homeowner with the means of turning the
domestic hot water down without affecting
the heating output.

Restriction in heating loop; remove
restriction, check valve stuck or closed
valve.
cold water at hot faucet
The most probable cause is reverse flow
through the heating loop from a stuck check
valve; repair or replace valve.
fan runs for cooling but not heating
Thermostat may be connected improperly.
Refer to
Electrical section for proper
installation.
heating during off cycle
Probable cause is thermal siphoning. See
check valve description for details; repair or
replace check valve. Check elevation of air
handler above water heater to see if
motorized valve required for positive shut-off.
24 hr pump timer cycle is engaged. Wait to
ensure pump shuts off after cycle is over
(1m-15sec or 5min). Pump timer starts upon
energizing of air handler with line voltage.