Error 1022 B

Safety precautions

1. Before any inspection isolate the boiler electrical supply at the isolator or fuse spur and switch the boiler off. Do not attempt internal repairs or wiring work unless you are qualified. If you have any doubt, stop and call a Gas Safe registered engineer. Avoid touching gas components or internal electronics. Allow hot parts to cool and beware of hot water in the cylinder.

2. Do not repeatedly press the reset button. One reset attempt is acceptable to clear a spurious fault; repeated resets can mask intermittent faults and may be unsafe.

Initial homeowner checks you can do

1. Note the error code and conditions. Record 1022 B and any other lights or codes displayed.

2. Try one reset: restore power, press the boiler reset button once and wait a few minutes to see if the fault clears and normal DHW operation resumes. If it returns immediately, proceed with checks below.

3. Visually inspect the hot water cylinder area and wiring run: look for obvious damage, wetness, corroded connectors, crushed or chewed cables, or a dislodged sensor pocket/clip on the cylinder.

4. Locate the hot water storage temperature sensor connector at the boiler wiring harness if accessible without opening the boiler casing. If you can safely access the external connector, switch the power off again, carefully unplug and re-seat the connector, then restore power and check for the error.

5. Check sensor mounting on the cylinder: the sensor should sit fully in its immersion pocket or be clipped to the cylinder where specified. If it has come out, push it fully back into position and secure it.

Diagnostic and specific fix steps (for competent DIYers only)

1. Tools required if you are comfortable working with low-voltage wiring: basic screwdriver set, multimeter. Only perform these with the power OFF.

2. With power isolated, unplug the sensor connector at the boiler or at the sensor end (where accessible). Measure the resistance across the sensor terminals using a multimeter. Typical hot water NTC values vary by model but you are checking for continuity and sensible resistance rather than an exact number. A healthy NTC will show a finite resistance at room temperature (not infinite) and the resistance should change when the sensor temperature is altered (warming the sensor slightly will reduce resistance for an NTC type). An open circuit (infinite resistance) or a hard short indicates a faulty sensor.

3. If the sensor shows open circuit or no change with temperature, replace the hot water storage temperature sensor with the correct Worcester part. If you are unsure of the part, record the boiler model and error code and contact a Gas Safe engineer or Worcester Bosch support.

4. If the sensor checks OK, measure continuity between the sensor connector and the boiler control harness to confirm wiring integrity. Check for short to earth. If wiring is open, intermittent, or corroded, the cable or connector will need repair or replacement.

5. Inspect and clean any connectors showing corrosion. Re-seat firmly. Ensure the sensor is mounted to give good thermal contact with the cylinder or immersion pocket; a loose sensor will give incorrect readings.

6. After any repair or replacement, restore power and test the boiler. Allow the boiler to run a DHW call and verify hot water production and that the 1022 B code does not reappear.

When to call a professional

1. If the basic reseating and visual checks do not clear the error, or if the fault returns after a reset, stop and call a Gas Safe registered engineer. Replace or internal wiring repairs, removal of the boiler casing, gas work, or control board testing must be done by a qualified engineer.

2. Tell the engineer the exact code 1022 B, what checks you have already carried out (reset, reseated connector, visual inspection, any multimeter readings if taken) — this speeds diagnosis.

3. A professional will safely replace the sensor, repair wiring or replace any defective control components and fully test the system for safe operation.

Final notes

Avoid repeated resets and do not attempt live electrical or gas-side repairs yourself. This fault is usually a straightforward sensor or connector issue but it must be resolved correctly to ensure accurate control and safe boiler operation.