Before you assume the dishwasher has failed, check the three things that account for most poor-cleaning complaints.
Dishwashers rarely stop cleaning suddenly. Performance fades, and by the time it is obvious, most people assume the machine is finished. In our experience the machine is usually fine — the conditions it is working in have changed.
1. Incoming water temperature
A dishwasher needs roughly 49–60°C water to dissolve detergent and cut grease. If your water heater is set low, or the dishwasher is far from it, the first fill arrives cold. Run the kitchen tap hot for thirty seconds before starting a cycle and see whether results improve — that single test tells you a lot.
2. Spray arm obstruction
- Spin each spray arm by hand — it should turn freely through a full rotation.
- Hold the arms up to the light and clear blocked jets with a toothpick.
- Check that tall items on the bottom rack are not stopping the upper arm.
- Confirm the upper rack's water feed connects properly when the rack is pushed in.
3. Loading and detergent
Do not pre-rinse to the point of sparkling — modern detergents need some soil to work against. Face soiled surfaces toward the centre, avoid nesting bowls and spoons, and use fresh detergent: tabs older than a year lose enzyme activity. Add rinse aid, especially in hard-water areas.
“Hot water, free spray arms, clean filter. Get those three right and most dishwashers clean like new again.”
If all three check out and dishes still come out gritty, the circulation pump, heating element or water inlet valve may be underperforming — worth a proper diagnosis rather than another bottle of rinse aid.