Washing · 5 min read
Why your dishwasher isn't cleaning properly
Spray-arm blockages, salt levels and filter maintenance explained. Includes descale routine.
Safety first — do not use the appliance
If you smell gas, call the National Gas Emergency Service on 0800 111 999. For immediate danger call 999.
This professional guide has been compiled by the Kettlebridge engineering team to help you diagnose and, where safe, resolve common appliance issues. We provide these steps based on thousands of successful repairs across the UK.
Follow the troubleshooting steps below in order. Remember: safety is paramount. If you encounter any step that involves live electricity, gas connections, or complex disassembly that you are not comfortable with, stop immediately and contact a professional.
Step-by-step checks
- Remove and rinse the spray arms. Take them off, run water through the holes, and re-fit. Blocked holes are the number-one cause.
- Check salt and rinse-aid levels. Hard-water areas need topping up more often. Low salt = poor cleaning.
- Clear the filter stack. Twist out the mesh filters at the base and rinse under a hot tap.
- Run a maintenance cycle. Hot cycle with dishwasher cleaner or citric acid every 1–2 months.
Safety notes
- Isolate power before removing any parts.
- Never use household bleach on stainless steel dishwasher interiors — it will pit the finish.
When to book a repair
If the water isn't reaching a suitable temperature or spray arms don't rotate, the heater or wash pump needs a professional look.