Modine Manufacturing SSD - Troubleshooting - Indoor Unit Issues (Cont.); Trouble H. No Heating (Hot Water); Trouble I. No Heating (Electric Heat); Trouble J. Electric Overheat

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8-504.11
TROUBLESHOOTING
Troubleshooting – Indoor Unit (cont.)
Trouble Possible Cause Possible Remedy
H. No Heating (Hot
Water)
1. Incorrect MODE setting. (Microprocessor units
only - Digit 8 = M)
1. Check that the transmitter MODE is set to Heat or Auto
Mode.
2. Set point too low.
2. Check the set point on the transmitter or wall mounted
thermostat and adjust if necessary.
3. Blocked or dirty lters causing low airow.
3. Check lters condition. (See page 32 for lter removal
and cleaning instructions)
4. No hot water / pumps failed. 4. Check hot water source and supply to unit.
5. Faulty valve / actuator.
5. Check actuator by manually opening and closing valve,
replace if faulty.
6. Faulty heater relay.
6. Check signals to relay and check action of relay contacts.
Replace relay or PCB if necessary.
I. No Heating (Electric
Heat)
1. Incorrect MODE setting. (Microprocessor units
only - Digit 8 = M)
1. Check that the transmitter MODE is set to Heat or Auto
Mode.
2. Set point too low..
2. Check the set point on the transmitter or wall mounted
thermostat and adjust if necessary.
3. Overheat cut out tripped. (See also section
“Electric Overheat”)
3. Investigate cause of overheat condition.
4. Possible low airow, check lter condition. (See page
32 for lter 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.
4. Heater element failed. 7. Investigate and replace if necessary.
5. Faulty heater relay.
8. Check signals to relay and check action of relay contacts.
Replace relay or PCB if necessary.
J. Electric Overheat The electric heat circuit contains one automatic reset and one manual reset overheat cut-out protection switch for
each electric heat element tted to the unit. The cut-outs are wired in line with the main power owing 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 ve minutes for the unit temperature to fall su󰀩ciently to
allow the cut-out to be reset. The cut-out should only be reset by a qualied and competent electrician by cycling
the main power to the unit. Ensure the elements have cooled su󰀩ciently.