Ice Machine Repair 101:
Ice machine repair can be tricky, but we will start with an obvious proposition. You need ice to make water. Now that we’ve cleared the simple concept, let’s dig deeper. There is a a mechanical device within all ice makers that automatically fills the water reservoir. There are two devices, most commonly, for water inlet control. Those are a float switch and a electromagnetic solenoid. The float switch is inside the water reservoir. If you look, you can see a round or square plastic float inside the water reservoir, which is connected to an arm. When the water level drops, the float in the water reservoir drops, which opens a valve that allows water into the pan/reservoir. On the other hand, the water inlet solenoid is usually located in the ice machine near where the water line enters the unit. The solenoid receives electrical voltage from a control panel, which controls the opening of the valve, and allows a certain amount of water to fill the pan.
How Your Ice Machine “Knows” That There is Enough Water to Make Ice
Different ice machine manufacturers use varying methods for the ice machine to detect when enough water has entered the water pan. If using a float switch, the water pan remains full of water. Water enters the pan whenever the water level drops. The use of a water inlet solenoid requires a second sensing device, which tells the solenoid when to turn off the flow of water coming into the water pan. Some ice machines use a water float that switches off the water inlet solenoid when the water raises to a certain level. Other machines use water sensors for the same detection. The water sensor is usually part of a DC voltage control board. The sensor is simply a metal probe that completes a ground when the water touches the metal probe. When the ground for the DC circuit is complete, the computer board inside the ice maker closes the AC current to the solenoid.
In summary, if your ice machine does not get enough water in the water reservoir at the beginning of the ice making freeze stage, you need to check the water inlet valve. You can find the water inlet valve by following the water line that goes into the ice maker. This will lead you to this valve.
Lime scale is usually what causes a float valve to stop working. This scale builds up in all ice machine when the water freezes, turns into ice minerals, which will not freeze but stay behind in the water pan to make the dreaded lime scale. Over time, this build up clings to the inside parts that come into contact with water. Eventually, the lime scale will damage the inlet valve or prevent it from allowing water to flow through the valve. This build up will also damage any inlet valve controlled by a solenoid. In those cases, the valve can be taken apart and cleaned. You can find a screen on the inlet side of the valve, which collects this lime scale. You may attempt to clean this screen if you are able. Also, you should clean the diaphragm of the valve. However, very often when the inlet valve becomes unworkable, a replacement is in order. Usually by the time an inlet valve becomes fouled, it needs to be replaced with a new one.
You can control scale building up in the water inlet value by using a good ice machine water filter. We will save the water filter discussion for another blog entry. But another way to control the destructive scale buildup is by cleaning your ice maker. When I suggest that you clean an ice machine, I do not mean taking stainless steel cleaner to the outside of the cabinet. The only way to properly clean an ice machine is to use a professional cleaning solution, specifically approved for ice machines,and follow the manufactures recommended procedures. We will save a detailed cleaning discussion for another day, but you should know that if you clean with the wrong chemical, you can destroy your evaporator plate.
In A Nutshell
So we’ve come full circle to get back to the idea that your ice machine needs water to make ice. So simple. The key to repairing ice machines is to make sure this water is flowing. This means first checking the water line going into the machine. If that is working, the next step involve in repairing an ice machine is making sure your water inlet valve is working. We’ll save filters and cleaning for another day.
But the take home message should be that preventive maintenance to reduce scale buildup with a water filter and remove scale with regular cleaning is the best defense against water inlet valve failure.