Quick Answer:
If you hear a pop behind the refrigerator right when the ice maker finishes filling, it’s usually a water-hammer or a fast shutoff of the small plastic line — not the line blowing off. Pull the fridge out carefully, watch the ice-maker fill, and feel the tubing during shutoff to confirm the noise. If the shutoff is a saddle valve or a hidden/buried valve, a plumber can replace it with a proper shutoff to stop the banging without risking the fridge supply line.
Why This Happens
Most modern ice makers use a small-diameter plastic or copper tube and a solenoid valve that stops water flow quickly. When moving water stops suddenly, it creates a pressure spike and a short, sharp knock or pop in the line. This is the same principle behind bigger household noises in other systems: rapid valve closure, loose fittings, or an undersized shutoff can let the tube move or flex and make noise.
The issue is usually pressure and rapid shutoff, not an immediate danger of the tubing detaching. If the shutoff hardware is a temporary saddle valve or the feed valve is inaccessible or buried, that can make the system more likely to bang and harder to adjust — in those cases a plumber can install a proper shutoff valve safely.
Step-by-Step What to Do
Step 1 — Pull the fridge out carefully
- Unplug the fridge and move it out from the wall slowly. Keep any ice or water lines supported to avoid stretching or kinking them.
- Work on a stable floor; remove the toe kick if needed for easier access and to see the valve and tubing clearly.
Step 2 — Watch and feel during a fill cycle
- Let the ice maker run a normal harvest and wait for the next fill. You can trigger a fill if your model has a test mode, otherwise wait for the automatic cycle.
- Stand behind the fridge and place a gloved hand on the plastic or copper tubing near the valve. You’re checking whether the tubing snaps or shifts exactly when the valve shuts off.
Step 3 — Identify the feed valve type
- Look at the shutoff where the fridge tubing connects. Common types are an angle stop (a small solid valve on the wall), a compression valve, or a saddle valve clamped to a water line.
- If the valve is under drywall, buried, or a crimp-on saddle valve, note that it’s not an ideal long-term solution.
Step 4 — Reduce flow slightly and retest
- Gently reduce the flow at the shutoff by turning the valve a small amount toward closed — about a quarter turn — to slow the water slightly. Don’t close the valve fully unless you intend to shut the water off.
- Run another ice-maker fill and feel whether the pop changes. A reduced flow that softens the snap suggests the noise is caused by a rapid shutdown and pressure surge.
- If the noise lessens, you’ve confirmed pressure/flow as the cause. The permanent fix is usually to replace or upgrade the valve rather than to keep the feed partially closed.
What Not to Do
- Don’t sharply bend plastic tubing or pinch the line to try to quiet the noise — that risks kinking, restricting water, or cracking the line.
- Don’t rely on a saddle valve or a hidden/buried temporary valve as a long-term fix. If the feed valve is a saddle valve or hidden, a plumber can install a proper shutoff without damaging the fridge line.
- Avoid over-tightening fittings or forcing the fridge line while the appliance is connected; that can break the connector or create leaks.
When to Call a Professional
- Call a plumber if the pop continues after flow adjustment, if you see any leaks, or if the feed valve is a saddle valve or buried behind drywall. A plumber can install a proper angle stop or accessible shutoff and add a pressure arrestor if needed.
- Also call help if you’re uncomfortable moving the fridge, working near the water line, or if the tubing shows wear or cracking. A pro will safely upgrade the valve without stressing the small fridge supply line.
Safety Notes
- Turn off power to the fridge before moving it or working behind it to avoid electrical hazards.
- Support the water line and avoid pulling on it. If you must disconnect the line, be prepared with towels and a small bucket for residual water.
- If you suspect a leak or a cracked line, shut off the water supply and call a plumber right away.
Common Homeowner Questions
- Will the small plastic line blow off? — Very unlikely; the pop is usually a pressure spike. Inspect fittings and, if needed, have a plumber replace weak connectors.
- Can I fix this by myself? — You can check and reduce flow as described and identify valve type, but replace or upgrade of hidden or saddle valves is best done by a plumber.
- Is this related to other noisy plumbing in the house? — Yes, it’s the same basic issue as other pressure-shutdown noises; see Loud bang when washing machine stops and Pipes bang only at night for similar situations and fixes.
For more related articles, see the Pipes Banging After Fixtures Turn Off hub.