20
TROUBLESHOOTING
M O S T L I K E L Y P R O B L E M S
A N D C A U S E S
Important:
For system to operate properly power should be turned
ON and all shut-off valves/isolation valves must be open.
If Pump Does Not Run:
1. Circuit board controls operation of pump.
Check that pump LED is illuminated.
Check for 24VAC at pump terminal on circuit board.
If faulty refer to “Faulty Circuit Board” section.
2. Check line voltage wiring to pump. Check for 120 VAC
at pump relay and inside the pump electrical box.
Pump is Noisy:
Air may be trapped in the water circuit. Purge air from the
system as described under “start-up procedure”.
Insufficient or No Heat:
1. Air may still be trapped in heating loop. Purge air from
the system as described under “start-up procedure”.
2. Water heater thermostat not turned up high enough.
(Remember, higher than 120 °F = mixing valve for
domestic service).
3. Inlet and outlet piping connection at the Air Handler
may be reversed. See Figure 2.
4. Water heater thermostat not calibrated properly.
5. Excessive pressure drop caused by restriction
somewhere in the hot water loop does not allow
sufficient water to flow to Air Handler.
6. Air Handler not sized large enough for heat load.
7. Water heater not large enough to satisfy heat load.
ECM Motor Won’t Start:
Disconnect power before plugging/ unplugging
motor cables.
CAUTION – motor is supplied with 120 VAC continuously.
24VAC thermostat signals communicate with the motor
to initiate operation.
1. Circuit board controls the blower motor in Heating mode.
Check that LOW FAN or HIGH FAN LED is illuminated.
Also check for 24VAC at these terminals on the circuit
board. If faulty refer to “Faulty Circuit Board” section.
2. Ensure motor cables are properly installed and firmly
plugged into the motor. Check voltages in the cables.
3. Check door switch depressed, power supply, and
thermostat lines are wired properly. Refer to the
electrical diagram supplied with each Air Handler.
4. Check the voltages at motor plugs (120VAC and 24VAC).
5. There may be a faulty TAP on the motor. Select a
different speed on the motor tap selection tree.
Refer to Figure 13.
Possible defective motor. Contact RedZone
TM
for assistance.
When ordering a new motor the Air Handler model number
and serial number will be required.
Each EC motor must be programmed with the same
torque settings as the original motor to operate properly.
Faulty Circuit Board:
The circuit board has a Green power LED and 3
function LEDs. When any of the 3 output LEDs are
illuminated 24VAC is supplied to the corresponding
¼” Spade terminal on the board.
If the Green power LED is not illuminated check that the
board fuse is not blown and replace if necessary.
If there is malfunction a temporary circuit board bypassed
can be utilized until a replacement circuit board is installed.
With the power off:
1. Remove the fuse from the circuit board
2. Move the “PUMP” wire (Orange/Black stripe) and the
“High Fan” wire (White/Red Stripe) to the two extra
W terminals.
This will allow the pump and blower to run with a call
for heat from the thermostat.
R E D Z O N E
T M
D V S S E R I E S A I R H A N D L E R M A N U A L
