Modine Manufacturing SSD Installation And Service Manual page 38

TROUBLESHOOTING
Tr oubleshooting – Indoor Unit (cont.)
Trouble
H. No Heating (Hot
Water)
I. No Heating (Electric
Heat)
J. Electric Overheat
38
Possible Cause
1. Incorrect MODE setting. (Microprocessor units
only - Digit 8 = M)
2. Set point too low.
3. Blocked or dirty filters causing low airflow.
4. No hot water / pumps failed.
5. Faulty valve / actuator.
6. Faulty heater relay.
1. Incorrect MODE setting. (Microprocessor units
only - Digit 8 = M)
2. Set point too low..
3. Overheat cut out tripped. (See also section
"Electric Overheat")
4. Heater element failed.
5. Faulty heater relay.
The electric heat circuit contains one automatic reset and one manual reset overheat cut-out protection switch for
each electric heat element fitted to the unit. The cut-outs are wired in line with the main power flowing in each
element and operate as described below.
1. Auto Cut-out – if the auto cut-out trips, the electric heat is temporarily disabled until the unit temperature falls
and causes the overheat cut-out to automatically reset.
2. Manual Cut-out – if the manual cut-out trips, the electric heat is disabled until the unit temperature falls and the
overheat cut-out is manually reset. It will typically take five minutes for the unit temperature to fall sufficiently to
allow the cut-out to be reset. The cut-out should only be reset by a qualified and competent electrician by cycling
the main power to the unit. Ensure the elements have cooled sufficiently.
1. Check that the transmitter MODE is set to Heat or Auto
Mode.
2. Check the set point on the transmitter or wall mounted
thermostat and adjust if necessary.
3. Check filters condition. (See page 32 for filter removal
and cleaning instructions)
4. Check hot water source and supply to unit.
5. Check actuator by manually opening and closing valve,
replace if faulty.
6. Check signals to relay and check action of relay contacts.
Replace relay or PCB if necessary.
1. Check that the transmitter MODE is set to Heat or Auto
Mode.
2. Check the set point on the transmitter or wall mounted
thermostat and adjust if necessary.
3. Investigate cause of overheat condition.
4. Possible low airflow, check filter condition. (See page
32 for filter removal and cleaning instructions)
5. Possible fan failure. Check fans.(See section "C. Fans
Will Not Run")
6. Reset manual overheat cut-out by cycling the main
power to the unit. Consult Factory for instructions if
necessary.
7. Investigate and replace if necessary.
8. Check signals to relay and check action of relay contacts.
Replace relay or PCB if necessary.
8-504.11
Possible Remedy