Bosch E02
Motor Fault
High severityExpert Guide
SeverityHigh
What Your Machine Is Actually Telling You
E02 (sometimes displayed as E:02 or Er:02) is Bosch's water inlet error. The control board activated the water inlet valve (Aquastop valve on Bosch models with the Aquastop system) but the flow meter or pressure switch didn't detect adequate water entering the drum within the expected timeframe.
What makes Bosch unique — the Aquastop system: Unlike most brands that use simple solenoid valves, many Bosch washers have an Aquastop hose — a special inlet hose with a built-in safety valve. If this system detects a leak (water between the inner supply hose and the outer protective sheath), it permanently shuts off the water supply. This is an important distinction because a triggered Aquastop requires hose replacement, not just simple repairs.
How to tell if you have Aquastop: Look at the connection where your supply hose meets the wall tap. If there's a large rectangular or cylindrical housing (much larger than a normal hose connector), that's the Aquastop valve.
E02 causes (ranked):
1. Taps not fully open (15%) — especially after maintenance or moving.
2. Clogged inlet filters (35%) — mesh screens block with sediment over time.
3. Kinked or crushed hose (10%) — restricted water flow.
4. Aquastop triggered (15%) — the leak detect system activated.
5. Failed inlet valve / Aquastop valve (15%) — the solenoid won't open.
6. Low water pressure (10%) — below minimum requirement (~1 bar / 14.5 PSI).
Bosch's engineering heritage: Bosch builds their washers to BSH (Bosch Siemens Hausgerate) standards — the same inlet valve and Aquastop technology is used across Bosch and Siemens washers. So solutions that work for Bosch also apply to Siemens models.
What makes Bosch unique — the Aquastop system: Unlike most brands that use simple solenoid valves, many Bosch washers have an Aquastop hose — a special inlet hose with a built-in safety valve. If this system detects a leak (water between the inner supply hose and the outer protective sheath), it permanently shuts off the water supply. This is an important distinction because a triggered Aquastop requires hose replacement, not just simple repairs.
How to tell if you have Aquastop: Look at the connection where your supply hose meets the wall tap. If there's a large rectangular or cylindrical housing (much larger than a normal hose connector), that's the Aquastop valve.
E02 causes (ranked):
1. Taps not fully open (15%) — especially after maintenance or moving.
2. Clogged inlet filters (35%) — mesh screens block with sediment over time.
3. Kinked or crushed hose (10%) — restricted water flow.
4. Aquastop triggered (15%) — the leak detect system activated.
5. Failed inlet valve / Aquastop valve (15%) — the solenoid won't open.
6. Low water pressure (10%) — below minimum requirement (~1 bar / 14.5 PSI).
Bosch's engineering heritage: Bosch builds their washers to BSH (Bosch Siemens Hausgerate) standards — the same inlet valve and Aquastop technology is used across Bosch and Siemens washers. So solutions that work for Bosch also apply to Siemens models.
What You're Probably Seeing Right Now
- You pressed Start, the door locked, but no water is entering — the drum stays empty.
- The Aquastop hose has a red indicator dot visible in the viewing window — the safety system has triggered and permanently shut off water.
- Water fills very slowly — you can hear a faint trickle but after several minutes the drum is barely wet.
- E02 appears on hot cycles only — one side of the dual valve has failed while the other works.
- E02 appeared after a water main break or plumbing work in your building.
DIY Fix — From Easiest to Hardest
1
Check the Taps (30 seconds)
1. Walk behind the machine.
2. Turn both taps **fully counter-clockwise** until they stop.
3. On some Bosch installations, there's a single **quarter-turn ball valve** — make sure the handle is parallel to the pipe (open), not perpendicular (closed).
**Fixes ~15% of E02 cases.** Usually happens after plumbing work.
2. Turn both taps **fully counter-clockwise** until they stop.
3. On some Bosch installations, there's a single **quarter-turn ball valve** — make sure the handle is parallel to the pipe (open), not perpendicular (closed).
**Fixes ~15% of E02 cases.** Usually happens after plumbing work.
2
Check the Aquastop Indicator (1 minute — Aquastop Models Only)
If you have an Aquastop hose:
1. Look at the **connector housing** at the wall tap end.
2. Some models have a **small viewing window** — if the indicator shows **red**, the Aquastop has triggered.
3. A triggered Aquastop is **not resettable** — the entire Aquastop hose must be replaced.
4. Aquastop can be triggered by a **small leak inside the hose**, by removing the hose while the tap was open, or by a water hammer.
**Replacement cost:** Genuine Bosch Aquastop hose: $40-80. Universal hoses don't have the Aquastop feature.
1. Look at the **connector housing** at the wall tap end.
2. Some models have a **small viewing window** — if the indicator shows **red**, the Aquastop has triggered.
3. A triggered Aquastop is **not resettable** — the entire Aquastop hose must be replaced.
4. Aquastop can be triggered by a **small leak inside the hose**, by removing the hose while the tap was open, or by a water hammer.
**Replacement cost:** Genuine Bosch Aquastop hose: $40-80. Universal hoses don't have the Aquastop feature.
3
Clean the Inlet Mesh Filters (10 minutes)
**Fixes ~35% of E02 cases:**
1. Turn off taps. Have towels ready.
2. Unscrew the supply hoses from the **back of the machine** (not the wall).
3. Inside the threaded inlet ports: small **mesh screens.**
4. Pull screens out with needle-nose pliers.
5. Scrub with toothbrush under running water. Soak in vinegar if calcified.
6. Reinstall, reconnect hoses, turn taps on slowly, check for leaks.
**Bosch also has filters inside the Aquastop housing** — check the manual for access.
1. Turn off taps. Have towels ready.
2. Unscrew the supply hoses from the **back of the machine** (not the wall).
3. Inside the threaded inlet ports: small **mesh screens.**
4. Pull screens out with needle-nose pliers.
5. Scrub with toothbrush under running water. Soak in vinegar if calcified.
6. Reinstall, reconnect hoses, turn taps on slowly, check for leaks.
**Bosch also has filters inside the Aquastop housing** — check the manual for access.
4
Check for Kinked Hoses (2 minutes)
1. Pull machine forward 8-10 inches.
2. Inspect hoses for **sharp bends, crushing, or bulging.**
3. Straighten any kinks.
4. Ensure the machine hasn't been pushed back against the hoses.
**If hoses are old and stiff:** Upgrade to braided stainless steel hoses ($15-25 per pair).
2. Inspect hoses for **sharp bends, crushing, or bulging.**
3. Straighten any kinks.
4. Ensure the machine hasn't been pushed back against the hoses.
**If hoses are old and stiff:** Upgrade to braided stainless steel hoses ($15-25 per pair).
5
The Bucket Test — Water Pressure Check (3 minutes)
1. Disconnect hoses from washer.
2. Point into a bucket, turn taps on for 30 seconds.
3. **Expected:** 1+ gallon per hose in 30 seconds.
4. **Weak flow:** Plumbing issue, not washer. Check upstream.
5. **Strong flow:** Inlet valve has failed.
**Bosch minimum:** ~1 bar (14.5 PSI). Anything less causes E02.
2. Point into a bucket, turn taps on for 30 seconds.
3. **Expected:** 1+ gallon per hose in 30 seconds.
4. **Weak flow:** Plumbing issue, not washer. Check upstream.
5. **Strong flow:** Inlet valve has failed.
**Bosch minimum:** ~1 bar (14.5 PSI). Anything less causes E02.
6
Test the Inlet Valve (10 minutes — Advanced)
If flow is good but the valve won't open:
1. Unplug, remove top panel.
2. Find the inlet valve (at the back where hoses connect, inside the machine).
3. Measure solenoid resistance: should be **2,000-4,000Ω.**
4. OL = open coil, dead valve. Replace.
5. Also check for **24V AC** at the valve connector during fill (machine running, probe carefully).
**Bosch valves** are model-specific — order using your E-Nr (Bosch model number, found on the door frame sticker).
1. Unplug, remove top panel.
2. Find the inlet valve (at the back where hoses connect, inside the machine).
3. Measure solenoid resistance: should be **2,000-4,000Ω.**
4. OL = open coil, dead valve. Replace.
5. Also check for **24V AC** at the valve connector during fill (machine running, probe carefully).
**Bosch valves** are model-specific — order using your E-Nr (Bosch model number, found on the door frame sticker).
When to Call a Pro
- •Aquastop triggered — Aquastop hose replacement: $100-$200 installed.
- •Inlet valve confirmed dead — Valve replacement: $120-$250 with labor.
- •Low household water pressure — plumber needed. May require a pressure booster: $200-$500.
- •E02 on electronic Aquastop (newer models) — the electronic fault detection requires diagnostic tools. Professional: $100-$200.
What It'll Cost You
Swipe left to see full table