Milnor Dryer Troubleshooting

Milnor dryer troubleshooting

This page contains several tables describing possible issues which may happen to Milnor dryer as well as their fault codes. There are lists for M30V, M175, and M115 models. Here you can find symptoms description and error codes which are shown on a digit display.

These tables help with Milnor dryer troubleshooting, giving the probable cause of an issue and a remedy which can help solve the problem. For each problem there are several possible causes and remedies.

If you realize that the suggested remedy is complicated for you to perform by yourself, call a specialist and let them do all what is necessary. The tables have only recommendatory purpose.

Milnor M30V Dryer Troubleshooting

SymptomProbable CauseSuggested Remedy
Tumbler does not turnDrive beltsCheck both drive belts. Replace if failed.
Tumbler does not turnCheck capacitor and motor. Replace if failed
Door switchCheck door switch contacts and adjustment. Adjust or replace door switch.
Timer Tumbler does not turnCheck to see if heat timer is turned on
Tumbler turns but no spark at burnerGlass fuseCheck small glass control fuse in back of dryer. Replace if failed.
ThermostatCheck if voltage is passing through the two wires attached to the temoprature thermostat
IgnitionCheck for 24VAC output from transformer.
TransformerReplace if have 120V between black & white and no 24V between red and yellow.
Over temperatureCheck to see if manually resettable thermostat. Thermostat is kicked out. Reset by pushing red reset button.
Ignition controlCheck for 24VAC coming into the control on the at burner red wire. If voltage, then check for 24VAC out on the brown wire. Also check for spark at the ignitor. If no 24VAC output or no spark to the ignitor, replace ignition control.
Air Flow SwitchCheck air flow switch to be sure it closes when dryer is running. If not, adjust or replace switch.
Hi-limitCheck for continuity. Should be 0 ohms resistance when cold. If not, replace thermostat.
Gas supplyNo gas can cause system lockout

Milnor M175 Dryer Troubleshooting

SymptomProbable CauseSuggested Remedy
Tumbler turns, ignition sparks, no flameGas supplyMake sure gas supply is working.
Gas pressureMake manometer check of gas pressure. Adjust if necessary.
Spark Electrode SensorCheck for damage to electrode or mounting. Replace if necessary.
Gas valveCheck coil continuity, replace valve if failed.
Ignition ControlCheck for 24VAC to gas valve coils. If no voltage replace ignition control.
Burner Lights, but goes on and offElectrodesCheck low voltage harness for possible wire break or cuts to allow no signal back to ignition control
Slow dryingTemperature SettingCheck thermostat for correct high temperature setting. Adjust if necessary.
Air flow restrictions necessary1. Check lint screen and dean if necessary.
2. Check exhaust for correct length and clean if necessary.
3. Check exhaust damper to insure that it opens when dryer is running and closes when dryer is not in use.
4. Check makeup air to insure that it is adequate. Increase makeup air if necessary.
5. Check static Back pressure no more than .3
Manual overtemp Tripping FrequentlyRecirculating chamber Lint AccumulationRemove manual overtemp thermostat and inspect in chamber for excessive lint build up. Access also gained to this chamber by removing recirculation duct mounted at bottom of chamber, or the panel inside burner chamber between burners and rear back panel
Exhaust ducting Excessive lint buildupRemove exhaust duct at rear of dryer and inspect for excessive lint build up in complete duct from dryer to where duct exits building.
Clean lint from top heat air chamber above tumblerRemove front panel completely. Be careful of any wiring attached. Remove heated air chamber cover and clean above tumbler back to burner housing.

Milnor dryer error codes

FAULT FAULT DESCRIPTIONACTION
FIShorted thermostat sensor.Dryer stops and "FI" flashes on the 4-digit display. When short circuit on sensor input is removed, "LOAd" appears on the 4-digit display and the remaining dry time is reset.
F2Open thermostat sensor.Dryer stops and "F2" flashes on the 4-digit display. When a good sensor is connected to sensor input, "LOAd" appears on the 4-digit display and the remaining dry time is reset.
F3EEPROM corruptedDryer will not start and "F3" appears on the 4-digit display. The power to the dryer must be cycled to reset the controller. Fault should only occur when starting a dry cycle.
F4Gas valve on fault.The drying temperature did not increase 1°F. in 5 minutes. "F4" will flash on the display and the dry cycle will finish without calling for heat (energizing gas valve). Opening the door or pressing the STOP touch pad switch will reset the fault and clear the remaining time in the dry cycle.
F5Temperature faultThe drying temperature is at least 25°F. above the temperature setting. "F5" will flash on the 4-digit display and the dry cycle will finish without calling for heat (energizing the gas valve). The power to the dryer must be cycled to reset the controller.