How Your Ice Machine Makes Ice
We will state the obvious to start. To make ice one must have water. Okay now that we have an understanding of the obvious we can continue. A mechanical device within any and all makes of ice machines must automatically fill the water reservoir. Two common devices for water inlet control are a float switch and a electromagnetic solenoid. A float switch can be found inside the water reservoir itself. You will see a round or square plastic float connected to an arm. As the water level drops, the float drops in the water reservoir and opens a valve allowing water to enter the pan/reservoir. Conversely, the water inlet solenoid is generally located in the ice machine near the area where the water line enters the unit. The solenoid receives electrical voltage from the control panel, which opens the valve allowing a prescribed amount of water to fill the pan.
How Does Your Ice Machine “Know” There is Enough Water to Make Ice?
Different ice maker manufacturers use different methods of knowing when enough water has entered the water pan. In the case of using a float switch, the water pan is always full of water and water enters the pan whenever the water level drops. Use of a water inlet solenoid requires a second sensing device to tell the solenoid when to turn of the flow of water to the water pan. Some ice machines use a water float that turns off the water inlet solenoid once the water raises to a certain level. Another method is to use a water sensor. The water sensor is usually part of a DC voltage control board. The sensor is simply a metal probe that completes a ground once the water touches the metal probe. As the ground for the DC circuit is completed, a computer board inside the ice machine closes the AC current to the solenoid.
In short, if your ice machine is not getting water in the water reservoir at the start of the ice making freeze stage, check the water inlet valve. To find the water inlet valve, follow the water line that goes into the ice machine. Doing so will lead you to this valve.
The Dreaded Lime Scale
A float valve will usually work until it becomes fouled with lime scale. Scale build up occurs in all ice machines as the water freezes into ice the minerals will not freeze but stay behind in the water pan. Over time, this scale clings to the internal parts that any water comes into contact with. At some point, it will damage the inlet valve or close it off to where it will not allow water to flow through the valve. Scale buildup will also damage an inlet valve that is controlled by a solenoid. This type of valve can be taken apart and cleaned. There is a screen on the inlet side of this valve that collects scale buildup. Clean this screen. Also, clean the diaphragm of the valve. Usually by the time an inlet valve becomes fouled, it needs to be replaced with a new one.
How Failure to Properly Clean May Lead to Equipment Failure
Scale buildup in the water inlet valves can be controlled by the use of a good ice machine water filter, which we will discuss at a later time since too much information at one time for the human brain can be dangerous. Another way to control lime scale buildup is by cleaning your ice machine. By cleaning an ice machine, I do not mean using stainless steel cleaner on the outside of the cabinet. To properly clean an ice machine, you have to use a cleaning solution approved for ice machines and follow the manufactures recommended procedures. We will not go into the cleaning stuff right now but let me just tell you that if it is done with the wrong chemical, you can destroy your evaporator plate.
Back to the Basics
So the ice machine must have water to make ice. If it is not getting water, make sure the machine is getting water to it through the water line going to the machine. If you know water is flowing to the machine, check the water inlet valve to make sure it is working.
The bottom line in this discussion is that preventative maintenance to keep scale buildup down with a water filter and to remove scale with regular cleaning is the best defense against water inlet valve failure.