Samsung Washer 4C2 Error — Hot Cold Hoses Swapped Fix

What it means

Samsung washer 4C2 error means the water entering through the cold inlet is much hotter than expected — Samsung's 'Hot/cold error'.
The most common cause is swapped hot and cold supply hoses at the back of the machine, common after installation or after maintenance work.

Affected Models

Samsung Front Load Washer
Samsung Top Load Washer
Samsung AddWash Washer
Samsung EcoBubble Washer
Samsung QuickDrive Washer

Common Causes

Hot and cold inlet hoses connected to the wrong taps (most common — swap them back)
Both hoses connected to the hot supply (some installs miss the cold)
Cold tap supply has been heated by adjacent hot pipe (rare)
Hot water cross-feed from the boiler (plumbing fault)
Faulty water inlet temperature sensor

How to Fix It

Identify the hoses.

At the back of the machine, find the two inlet hoses.
The hot hose usually has a red indicator or red ring; the cold has blue.
The inlet ports on the back of the washer are also labelled — look for the small H and C marks.
Confirm hose-to-tap pairing.

Trace each hose to its tap.
Touch each tap to feel hot vs cold.
If the hose marked 'cold' is connected to the hot tap, that's your problem.
Swap the hoses.

Turn off both taps.
Unscrew both hoses and reconnect each to the correct tap by colour.
Hand-tight is enough.
Turn taps back on, check for leaks.
Run a short cycle to verify.

Start a quick cycle.
If 4C2 doesn't reappear, the swap was the cause.
If 4C2 returns even with hoses correctly placed, the inlet temperature sensor has failed and needs replacement.

When to Call a Professional

The fix is almost always a five-minute hose swap.
Call a plumber if the cold tap genuinely supplies hot water with no washer connected — that's a household plumbing fault, not a washer issue.

Frequently Asked Questions

Why does Samsung 4C2 only appear on certain wash temperatures?

Because the temperature check only runs when the washer expects a cold fill.
On a hot wash the machine expects hot water in the cold pipe wouldn't be flagged.
On a cold or warm wash, finding hot water in the cold inlet is unexpected and triggers 4C2.
If 4C2 only appears on cold cycles and the hoses are clearly correct, the cold supply itself is being warmed somewhere (sun on outdoor pipes, adjacent hot pipe in the wall) — usually a plumber question.