hoshizaki ice machine beeping error code list?

Hoshizaki Ice Machine Troubleshooting

For 1 beep every 3 seconds:---

The HIGH TEMPERATURE SAFETY is activated, when the thermistor which is mounted on the suction line reaches a temperature of 127° F. When this occurs it will shut the unit down, trigger this alarm, and lock it out on a manual reset safety.

Some of the reasons for a High Temperature safety alarm are as follows.

You will find these possibilities included on the control board diagnostic label located in the compressor compartment.

Follow the instructions provided on the label to reset the alarm and check these areas to locate the problem.

First, check to see if there is a mechanical problem with the hot gas valve sticking open or with the control board relay sticking.

Check for a temperature differential across the hot gas valve. To check for a sticking relay, use a volt meter to check for voltage on pink wire, pin # 2 on the K1 connector.

Hot water migration can also cause this. This typically happens at night when the only piece of equipment requiring water flow is the ice machine. Hot water migration is a tough problem to find and to prove to the customer.
The best way to determine that this is happening is to place a temperature recorder on the inlet water line of the ice machine.
 The recorder will show when migration occurs. Usually hot water migration is due to a defective mixing valve in the existing plumbing. A good place to check is the pre-wash area at the dishwasher.

Another possibility is a stuck head master on a remote air cooled condenser unit operating in a high ambient

condition. The best way to check for this is to carefully touch the liquid line connection at the rear of the unit.

Also, check for heat at the inlet pipe to the receiver tank. If these areas are hot, the head master is likely

stuck in the bypass mode.The last possibility is a shorted thermistor. If the thermistor reads approximately 500 ohms or less the control board will lock out on this safety. A shorted thermistor will signal zero ohms and cause repeated shut down on HIGH TEMPERATURE SAFETY.

By following these suggestions, you should be able to resolve the problem that caused the HIGH

TEMPERATURE SAFETY alarm.

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For 2 beeps every 3 seconds:--

In this case, access the control box and you will find the orange LED marked 20 min. illuminated. By checking the control board

instructions label supplied with the board it can be

determined that the unit has run two consecutive 20 min.

harvest cycles.

Before the problem can be determined, the control board

must be reset. This can be accomplished by leaving

power applied to the unit and depressing the white reset

button in the corner of the board. The unit should now

start in the one minute fill cycle and be followed by the

initial harvest cycle which will last 20 minutes. A basic

check of this harvest cycle should narrow down the

possibilities which would cause a 20 min harvest cycle.

When the compressor starts, touch the discharge line and

the inlet and outlet of the hot gas valve. This will indicate

that the hot gas valve is opening, and that the discharge

vapor is hot enough for a timely harvest. If the outlet of

the valve is cooler than normal, the hot gas valve did not

open or is not opening enough to allow full hot gas flow.

If the hot gas valve does not open at all, a remote unit will

pull down in a vacuum because the liquid line solenoid is

closed in harvest. On smaller water-cooled units the

suction pressure will be close to that of a normal freeze

cycle. The high condenser pressure opens the water

regulating valve condensing the refrigerant and allowing

refrigerant flow to the TEV. The evaporator will frost

and the suction line temperature will never reach 48

degrees. In either case the suction line temperature never

reaching 48 degrees will cause a 20 min. harvest cycle.

A voltmeter should now be used to check for 115 volts to

the hot gas solenoid coil. If 115 volts is present the coil is

open or the valve body is stuck closed. If no voltage is

present the board is defective.

If the suction line temperature reaches 48 degrees check

the resistance of the thermistor. An open thermistor will

result in a consistent 20 minute harvest. The open

thermistor will need to be replaced. Take care to mount

the thermistor properly. The normal resistance of the

thermistor should correspond with the thermistor

resistance chart provided in the Tech Specs pocket guide.

Another possible cause is the TXV, or liquid line solenoid

leaking during the harvest cycle. If the TXV sensing bulb

is not secured on the suction line or if refrigerant is

exiting the expansion valve for any reason, it can cool off

the discharge vapor and cause an extended harvest

cycles. Check sensing bulb mounting and the operation of

the TXV in the freeze cycle by using normal diagnostic

procedures.

Refrigerant charge and compressor capacity is always a

question on long harvest cycles. If unit charge is in

question refer to the Tech-Specs pocket guide for normal

operating pressures and cycle times. An inefficient

compressor is probably the most difficult to troubleshoot.

Generally if a compressor is inefficient, suction pressure

will be higher than normal, discharge pressure will be

lower than normal, discharge vapor will be cooler than

normal and compressor amp draw will be lower than the

RLA. Use normal diagnostic procedures to determine a

weak compressor.

After checking these items , you should be able to resolve

the 20 minute harvest cycle shut down and resume

proper KM ice production.

For beeping 3 beeps every 3 seconds:---

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.

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.

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*If you get 4 beeps every 3 seconds the connection between K-4 has a short circuit.

*If you get 5 beeps every 3 seconds the connection between K-4 has an open circuit.

To reset the safeties, depress the white alarm reset button while the board is beeping.

**BIN CONTROL TEST: The new bin control assembly mounts in the unit using

the two thumbscrews that mounted the thermostatic bulb. To test the control, allow the

unit to cycle into freeze for approximately 1 minute. Push the actuator to the right and

the unit should shut down within 3 ~ 5 seconds. When you remove your hand, the unit

should restart in the 1 minute fill cycle within 3 ~ 5 seconds.

If the unit fails to operate properly, first check the position of dipswitch number 7 on

the control board. This switch must be in the “ON” position for this bin control to

operate. Next check the resistance readings of the bin control assembly. With the

wiring harness disconnected from the board, check resistance across the red and black

wires on the red connector (harness end). When the switch is in the bin full position

you should read approximately 15.8 K-ohms. When it is calling for ice you should

read approximately 7.8 K-ohms. If the readings correspond to these, check for a

board problem. This type of failure however, is very rare and all other possible

possibilities should be checked before replacing the board.

If you do not get the readings above, you must determine which portion of the bin

control assembly is at fault. There are two basic parts of this assembly. They are, the

resistor wiring harness and the bin control switch assembly.

The bin control switch assembly, consist of the actuator and the switch. To test

disconnect the switch assembly from the wiring harness. This will isolate the switch

assembly. Using your ohmmeter, check between the black and white wires on the

connector from the switch (The red wire in the switch connector is not used). When

the actuator is in the ice making position you should read a closed circuit. When it is

in the bin full position it should read open. If the switch does not react correctly, you

should replace the switch portion of the assembly.

After the switch portion has been checked and is working properly the next component

to check is the resistor wiring harness. The resistor wiring harness must be disconnected from both the board and the bin control switch assembly. Again,

using your ohmmeter test across the black and red wires on the red connector of the

wiring harness. You should read approximately 15.8K-ohms. Now, read across the

white and black wires on the other end and you should read approximately 31.6 Kohms. If your readings do not correspond to these then replace the resistor wiring

harness.

Note: After the unit has started, it will only shut

down at the end of harvest or during the first five

minutes of the freeze cycle. The unit will not shut

down during the one minute fill cycle even when

the bin control is in the bin full position.

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For beeping 6 times:---

This is an indication that the unit is off on a low voltage safety. If the incoming voltage drops below 92 VAC+/- 5% the unit will de-energize the red LED and begin an audible alarm of six beeps every three seconds. The low voltage alarm is triggered by monitoring the secondary voltage of the transformer at the K2 connector on the control board. This alarm as well as the high voltage alarm will automatically reset when the proper voltage is restored.

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For beeping

7 beeps every 3 seconds:---

In this article we will

highlight the HIGH VOLTAGE SAFTEY which will be

signaled by 7 beeps every 3 seconds.

First, let’s discuss how the control board determines

that the machine is in a high voltage situation. This is one

by the control board monitoring the voltage at

the K2 connector or the secondary output from the

control voltage transformer. The proper voltage at the

output should be within 10.5 to 12.0 volts. If this

voltage increases due to primary voltage to the

transformer increasing to 142 vac. or higher, the unit will

shut down on a automatic reset high voltage safety. A

red LED on the board lights up when the control voltage

is correct. If the high voltage safety operates, this light

will be extinguished.

Now, let’s discuss the possible causes for this situation.

The first possibility would be if the supply power to the

unit was installed incorrectly (improper wiring). A

possible scenario could be that line voltage was supplied

to the neutral wire on a 208-230 volt unit or 208-230

volts is being supplied to a 115 volt unit. This would

cause the primary voltage to the transformer to be 208-

230 meaning that the secondary voltage will exceed the

boards threshold and shut down on the high voltage

safety.

The second reason is the existence of a “stinger leg” or

a “wild leg” in the voltage supply. This is a leg of power

that supplies over 150 vac. to ground. This leg, if

installed on the brown wire, will supply high voltage to

the transformer primary causing higher voltage on the

secondary. The unit will shut down on high voltage

safety. To operate the machine using a stinger leg, it

must always be connected to the black wire

(compressor circuit) in the unit junction box.

The third possibility is if the unit experiences a voltage

surge during normal operation. Any increase in the

incoming voltage will increase the control transformer

output. If this voltage surge reaches 142 vac. the unitwill shut down on the high voltage safety to protect

itself from damage.

It is important to note that the high voltage safety

protection will automatically reset itself when the wiring

is corrected or when the voltage returns to normal.

Check each of these items if the board signals 7 beeps.

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