6 beeps on km500mah ice machine. Starts to fill unit and when it switches to compressor mode, the system stops and 6 beeps.

Have a look at the side of the evaporator; there is a probe (thermistor) attached to it that tells the control board when to initiate the harvest cycle. make sure it's clean and attached properly and doesn't need replacing. If hitting the float switch initiates the harvest cycle it sounds like you have a blocked/ scaled water tube or switch housing. take off the bottom of the switch assembly (black rubber bit) and clean through to the water chamber. run a cycle of descaler before trying again.

When first turned on, the sump should fill with water. If it does, water solenoid is good. If you have a full sump, and no water pump running, sometimes the "Ice/Off/Wash" switch is bad. Put switch in wash, if pump runs, it's good. Now put in Ice position, if sump fills and pump does not come on and compressor indicates it is in the freeze cycle, replace that switch first. Simplest place to start and lest costly to fix.

Well aside from jacking the machine up and putting another in its place, the only thing left is the electronic thermometer/thermostat that should be sensing the ice and not the outside temperature. By the way, if you spend more than the machine is worth think about another one.

float switch is stuck in the "down" position. The unit goes thru a fill cycle and after 1 minute, the board "Looks" at the float swith to "see" if the sump is full. If float is stuck down, it tells the board that the unit does not have enough water and stays in the fill cycle. The compressor will not come on as long as the machine "thinks" there is not enough water. let me know if I can help further

Look for a stuck float switch. unit fills with water for 1 minute, then the board "looks" at the float to "see" if there is enough water in the unit to run. If float switch is stuck down, it tells the unit there is not enough water and the unit stays in the fill cycle causing the sump to overflow and send water down the drain constantly. Compressor will not run till the board senses that there is enough water to run.

when the machine first starts, it begins it's cycle in the harvest mode. If the float switch is stuck, it stays in the fill/ harvest mode. Compressor runs and water circulates but no ice is being made. I'd start looking there. Turn the machine on, let it run for about 3 minutes, they very lightly tap the float switch. If it starts making ice, bingo, theres your problem. Let me know if I can be of any more help.

Bad float switch.

3 beeps means the machine has ran two 1 hour cycles back to back to make ice an average timeframe for ice making is 25-30 min. Could be several issues, float switch dirty, water valve leaking by, dirty spray tubes, dirty evap., then go to refrigeration Expansion valve, compressor, charge, Hot gas valve leaking by,,,,,

I have a Hoshizaki KM-250BAF that is making 3 beeps then pauses and them makes 3 beeps again. If I unplug the ice maker and plug it in it continues to make the 3 beeps. The manual does not mention anything about beeps. Can anyone help?

(Quated From Hoshizaki Technical Bulletin)
An alarm code of 3 beeps
every 3 seconds means that the control board has shut
down on the 60 minute freeze cycle back up timer.

The “E” control board has a 60 minute timer that starts at
the beginning of the freeze cycle. If the float switch fails
to open and start the next harvest within 60 minutes, the
board will automatically start the harvest cycle. If this
occurs in two consecutive cycles, the control board will
shut the unit down on the manual reset, freeze cycle
back- up timer. The yellow fault LED marked “60 min.”
will illuminate. This safety is designed to help prevent a
freeze up of the evaporator.

Once you have identified the 60 minute alarm, there are
several things to check. Reset the alarm by depressing
the white reset button to the right of the fault LED’s.
This must be done with the power “ON”. Now check the
float switch to see if it is stuck in the up position. A stuck
float can occur if scale is present on the reed switch
shaft inside the housing. To check it, drain the water
reservoir, unplug the black float switch connector (K5)
from the control board and check it with an ohm meter
for a closed switch (zero ohms). If the float switch is
sticking, clean it with ice machine cleaner or replace it as
necessary.
An inlet water valve which is slowly leaking by during the
freeze cycle can cause a 60 minute alarm. If the inlet
water valve is stuck wide open, it is unlikely that any ice
will form on the evaporator. Check for a slow leak by
allowing the unit to cycle into the freeze cycle and
disconnecting the hose at the outlet of the water valve. If
water leaks by during the freeze cycle, the water valve
diaphragm is likely damaged or the small diaphragm bleed
port is clogged with scale. Clean the bleed port or replace
the diaphragm or entire water valve as necessary.

(I Recommend to get a refrigeration tech for this part).

Another possibility is a refrigeration system problem. You
should use normal refrigeration diagnosis procedures to
check for one of these problems. If the thermostatic
expansion valve is not feeding properly or the refrigerant
charge is low, the evaporator will not form ice as it should
and a long freeze cycle will occur. This could also be the
result of the hot gas valve not closing completely during
the freeze cycle or if the compressor valves are weak or
inefficient. An inefficient compressor however, will
usually show up first on the KM model through a longer
than normal harvest cycle. This is because of cooler
than normal discharge gas. Use proper refrigeration
practices to repair a refrigeration system problem.
While these are not the only reasons for a 60 minute
freeze cycle, they are the most common and should be
checked to resolve a 3 beep/yellow fault LED alarm.