How to Connect Washing Machine to Tap | Inlet Thread & Seals

Connecting a washing machine to a tap means attaching the inlet hose to both the washer and a compatible 3/4-inch threaded tap, then opening the water slowly to check for leaks.

The most common mistake is skipping the rubber seal or cross-threading the nut, which guarantees a drip. Whether replacing an old machine or moving one, the connection follows the same logic: hot line to hot inlet, cold line to cold inlet, then a slow open and a leak check.

What You Need Before You Start

Nearly every residential washing machine connects to a standard 3/4-inch threaded tap. Confirm your tap matches that thread before touching anything.

If your tap is an odd shape — a smooth spout without threads, or a smaller garden-style outlet — you need a tap adapter. These plastic or brass fittings screw onto the tap and give the hose a standard thread to bite into. Hardware stores carry them for a few dollars, and Bosch’s Malaysia guide notes adapters are sold separately.

• The inlet hose that came with the washer (usually one hot and one cold line)
• The rubber seals already fitted inside each hose nut
• A tap adapter only if your tap lacks standard threads
• Plumber’s tape —

The Step-by-Step Connection Process

Follow this order exactly to avoid leaks and kinked hoses.

1. Check the rubber seal inside each hose fitting. If missing or cracked, the connection will leak no matter how tight you crank it. Insert a fresh seal if needed.
2. Attach the hose to the washer inlet. The hot line goes to the red inlet, the cold line to the blue inlet. Screw each nut on by hand first, then tighten a quarter-turn with a wrench — never force it.
3. Attach the hose to the tap. If your tap has standard threads, screw the hose nut directly on. If it’s a smooth spout, fit the adapter first. Bosch’s Australia guide covers screw taps and ordinary taps with different methods — the principle is a firm, even thread.
4. Wrap plumber’s tape around the tap threads before connecting if you’re in a hard-water area or want extra drip insurance. Apply it clockwise so it doesn’t unravel as you tighten.
5. Open the tap slowly. Turn it just a crack, wait for the hose to fill with a hiss, then open fully. A slow opening prevents water hammer — the loud bang when pressure hits an empty hose.
6. Check every joint for leaks. Inspect where the hose meets the washer and the tap. Run your hand underneath each connection. If you see even a bead of moisture, tighten slightly and re-check.

Separate Hot and Cold Connections: What Goes Where

Most washers have two inlets, and mixing them up is a common error. The red inlet is always hot, the blue is always cold, matching the colors at both ends.

Some compact washers use only a cold water inlet — they heat water internally. If your machine has a single hose, connect it to the cold tap. For a washer with two inlets but only one tap available, you’ll need a 2-way washing machine tap that splits the supply into two outlets.

If your setup has only a cold supply but the washer has both inlets, LG’s inlet hose installation guidance covers connecting the cold line and capping the hot inlet. The same manual also walks through reversing hoses if marked differently.

Leak Prevention and Common Mistakes

Leaks happen for four reasons: a missing rubber seal, overtightening, a kinked hose, or mismatched threads. Bosch’s guidance stresses checking for leakage after opening the tap, and their Malaysia guide flags white plumber’s tape as compulsory. Avoid sharp bends and folded hoses — a creased line restricts flow and can cause the machine to run slow or error out.

Overtightening is the quiet killer. The nut only needs to be snug enough that the rubber seal compresses — a quarter turn past hand-tight is usually perfect. Cranking it until it won’t move warps the seal and creates a drip.