Many modern refrigerators have integrated ice makers with door dispensers. These devices can be useful, but they can also create trouble. If your ice maker was running fine one day but left you stuck with hot drinks the next, then there may be latent underlying causes. Below are three likely reasons for an ice maker that refuses to do its job.

1. Filter Clogs

Anything that regulates water flows to the ice maker can stop it from creating ice, especially if it becomes clogged. You should typically replace your refrigerator’s water filter about twice per year. Ignoring this maintenance step can cause problems with your water dispenser as well as your ice maker. If you cannot get ice or water from your fridge, then the filter should be your first suspect.

2. Bad Inlet Valve

A failing inlet valve is another potential source of ice maker trouble. If the water valve fails in the closed position or becomes blocked, water will not reach the ice maker. This type of failure can produce similar symptoms to many other problems, so a repair technician will usually want to rule out other possible issues before suspecting the valve.

In some cases, the inlet valve can also fail in the open position. When this happens, water can overflow the ice tray and even flood your refrigerator. A less dramatic failure can occur if the extra water causes your ice tray to fill with ice. The backed-up ice can result in your water fill tube freezing, so a faulty valve may be the issue if your fill tube repeatedly freezes after you defrost it.

3. Frozen Fill Tubes

Most ice makers use a small water fill tube to fill the ice-making tray. In some cases, the water in this tube can freeze and create a blockage that prevents the system from functioning correctly. Depending on the type of refrigerator that you own, there may be an integrated defroster unit that helps to stop this condition from occurring.

You can attempt to defrost the ice maker using a small amount of hot water, but this may not fix the underlying problem. Be sure to also remove as much ice from the tray as possible since backed up ice can cause water in the tube to freeze.