Bosch Washer Water Inlet Valve Replacement

The two solenoids share one outlet into the detergent drawer, which is how Bosch blends temperatures electronically instead of with a mechanical selector.

How it fills#

The board opens each solenoid independently and can run both at once at different duty cycles to hit a precise temperature — for instance the hot valve at 60% and the cold at 100% for a specific warm setting. The cold supply also runs through Bosch's AquaStop hose (a solenoid, flood sensor, and mechanical shutoff in one), while the hot line uses a plain braided-steel hose — AquaStop is cold-only because the European designs it came from are usually cold-fill. That means the cold path has two valves in series: the AquaStop at the tap and the cold solenoid at the machine.

Reading the fill faults#

• E3 — fill timeout: the board opened the valve but the pressure sensor never saw enough water in time. Check the household supply valves, kinked hoses, a tripped AquaStop, and the inlet screens before suspecting the solenoids.
• E17 — overfill: water kept coming after the board closed the valve, so a solenoid is stuck open (usually mineral scale on the plunger). Replace it promptly to avoid a flood.
• Only hot or only cold on a warm wash: one solenoid has failed while the other still works — test each separately.
• Water dribbling into the drawer while the washer is off: that's a supply-side valve (the tap or AquaStop) leaking past its seat, a hose issue rather than the machine's valve.

Test the solenoids by unplugging the 4-pin connector (2 pins per solenoid) and metering each pair: a healthy Bosch solenoid reads 800–1,200 ohms, with an open circuit meaning a burned coil and a very low reading a short.

Replacing the valve#

1. Cut power and shut off both the hot and cold supply valves.
2. Disconnect the fill hoses at the rear (towels ready for drips).
3. Remove the top panel (two Torx T20 screws at the rear, slide back, lift off).
4. The dual-solenoid valve is at the rear-top where the fill hoses connect; unplug its 4-pin connector.
5. Release the hose clamp and pull the internal hose from the valve outlet to the dispenser.
6. Remove the mounting screws (Torx T15, usually 2) and slide the valve out through the rear openings.
7. Clean or replace the inlet screen filters before fitting the new valve — sediment there restricts flow and kills valves early.
8. Reassemble in reverse, open the supply, check for leaks, and run a warm wash to confirm both solenoids fire and blend.

Parts and cost#

Screens, sourcing, and lifespan#

You can't buy a single solenoid — the dual valve is one BSH part number, housing and outlet included. A clogged inlet screen is actually the most common cause of slow filling that looks like a bad valve, so pull each mesh screen with needle-nose pliers, rinse it, and check it yearly or whenever fill times climb. When you do order, use the 8-digit E-number on the rating plate inside the door rather than the model number, since it pins the exact production variant; BSH keeps parts for at least 10 years after a model ends. If the washer fills only cold, test the hot solenoid's resistance and confirm the hot hose is on the correct port — it's marked H on the valve.

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