I have a Scotsman SCE170a-1a undercounter ice maker it only freezes in the center of the evaporator. Compressor , fan and water pump all work. I suspect the hot gas bypass valve.

Hi, first make sure the switch is not in the clean position but to on. If it is in the on position and the water is circulating over evaporator plate and is running back into the water sump tray and compressor is running as you stated then check to make sure the hot gas valve is not letting hot gas leak through during freeze cycle, the way you can check is after start up wait about 5 minutes and check the temp entering the hot gas valve and the temp on the other side of the valve if temp is the same then valve is bad. The next thing to check is the refrigerant level this only can be done by adding service valves and weighing out the charge to see if it is low, if low then there is a leak. The freeze cycle is as follows. The compressor, fan motor and water pump are all operating and stay in a freeze cycle until the evaporator thermistor reaches 6.5 deg F. That signals the control board to place the unit into a harvest cycle.

The only way to make ice faster for this machine is done with cooler ambient room temperature and colder water temperature from supply water before it reaches water sump tray.

Is the machine producing ice thick enough to come off the evaporator plate? the machine will try to harvest 3 times before it locks out on long harvest. Harvest cycle: The compressor and hot gas valve are both powered during the harvest cycle. The fan and pump are off at this time. The machine stays in the harvest cycle until the evaporator thermistor senses 52 DEG F. If the bin is not full, the unit goes into another freeze cycle. I would check the Thermistor

There could be over 50 things that will not let that machine make ice so help me out. when in freeze mode is compressor running, is condenser fan running, is water pump running, check condenser coil to make sure it's not full of dirt if so blow it out, cut machine off if water sump tray is full of water and you can still here water coming in at all check water flote to much water coming in all the time will not let water freeze. Fell evaporator plate while running if warm to touch could be hot gas valve letting hot gas in to plate in freeze cycle. you need to call a service company

1. Possible cause. Water leak. Check purge valve, water curtain, sump, sump hose.
2. Air filters clogged. Clean air filters.
3. Dirty condenser. Clean condenser.
4. Restricted location, intake air to hot. Have machine moved.
5. Ice thickness sensor dirty or disconnected. Check ice thickness sensor probe.
6. Water distributor dirty. Remove and clean water distributor.
7. Inlet water valve leaks through during freeze cycle. Check water inlet valve.
8. Connected to hot water. Check for bleed through from missing check valve in building water supply.
9. Incomplete harvest. Check harvest system.
10.High pressure cut out opened. Check fan motor pressure control, check fan motor, check controller using test mode.
11. Fan motor pressure control open. Check fan pressure control.
12. Fan motor not turning. Check fan motor, check fan blade,check controller using test mode.
13.Water pump not pumping. Check pump motor,check controller using test mode.
14. Pump hose disconnected. Check hose.
15. Compressor not operating. check compressor contactor, check controller using test mode.
Check compressor start components, check PTCR resistance and temperature, check compressor voltage, check compressor windings.
16. Low refrigerant charge. Add some refrigerant and restart unit. If cycle time imporves, look for a leak.
17. Hot gas valve leaks through during freeze. Check hot gas valve for hot outlet during freeze.
18. Thermostatic expansion valve bulb loose. Check bulb.
19. Thermostatic expansion valve producing very low or high superheat. Check evaporator superheat, Change TXV if incorrect.
20. Compressor inefficent. Check compressor amp draw, if low and all else is correcy, change compressor.

Check to make sure the condenser coil is clean, fan motor is running during freeze cycle. High Ambient temp, Ventilation, The higher the temperature entering the condenser coil the higher the head pressure. Fan motor failure, pressure switch failure. The cut out pressure varies 400, 450 or 500 PSIG. Water supply failure. not enough water running over the evaporator plate will cause high presser.

Sorry cant be repaired The evaporator plate will need to be replaced with the plates loose like that it will cause the ice to hang up and not drop when in harvest. depending on how old the unit is it would be more affordable to replace the machine. coil cost 1800.00 labor 600.00, freon, dryer, 300.00.

You have a problem with float valve. See page # 8

http://www.scotsman-ice.com/docs/uploaded/sct/manual/SCE17MAN.pdf

dead compressor or start gear problem or start cap dead

If the evaporator is not getting cold, it could be lack of charge or the coil is dirty and not allowing the compressor to properly cool. Try cleaning the coil first.