Dishwashers
Dishes come out dirty
A dishwasher that suddenly leaves grit on plates or film on glasses is usually telling you that water is not reaching the dishes with enough force, or that the water itself is the problem. The fixes are cheap and rarely need a technician.
Run the hot tap at the sink for a few seconds before starting a cycle so the dishwasher fills with hot water. Detergent needs heat to dissolve, and a cold first fill is a common reason for poor results that has nothing to do with the machine.
1. Clean the filter
Most modern dishwashers use a removable filter at the base of the tub instead of a self-cleaning grinder. Food sludge collects there, and once it is full the same dirty water recirculates over your dishes.
- Remove the bottom rack and lift out the cylindrical filter, usually a quarter turn to unlock.
- Rinse it under the tap and use a soft brush on the fine mesh.
- Wipe the sump area underneath where the filter seats before refitting it.
A filter that has never been cleaned is the leading cause of a dishwasher that "stopped working" without any error.
2. Free the spray arms
The spray arms spin and fire water through small jets. Hard-water scale and food particles block those jets, so part of the rack gets no spray.
- Spin each arm by hand; it should turn freely without catching on tall items.
- Hold the arm up to the light and clear blocked nozzles with a toothpick.
- Check that nothing on the top rack droops down to stop the upper arm turning.
Large parts of Canada, including much of the Prairies and many areas drawing on groundwater, have hard water. Scale builds up on the heating element and spray jets and leaves a white film on glassware. A rinse aid and the occasional run with a dishwasher-safe descaler help; some machines also have a built-in water softener that needs salt.
3. Check loading and detergent
Even a healthy machine cleans poorly if the basics are off. Run through these before suspecting a fault.
| Issue | What to change |
|---|---|
| Nesting bowls and overlapping plates | Space items so water reaches every surface |
| Old or caked detergent | Use fresh detergent; tablets lose strength when damp |
| White film on glasses | Add rinse aid; consider descaling for hard water |
| Cold incoming water | Run the hot tap before the cycle starts |
Quick reference
| Symptom | Most likely cause |
|---|---|
| Grit or food left on dishes | Clogged filter or blocked spray arm jets |
| Cloudy or filmy glassware | Hard water and no rinse aid |
| One section clean, another dirty | Spray arm not rotating or blocked by tall items |
| No water entering at all | Inlet valve or float switch — beyond this guide |
If the filter is clean, the arms spin freely and water is hot but the machine still fails to fill, drain or heat, the fault may be the inlet valve, drain pump, heating element or control board. Those checks involve electrical testing and are best handled by a qualified technician.
Further reading
For how the wash cycle and components fit together, see the publicly available Wikipedia article on dishwashers. Water hardness data for many municipalities is published by local utilities and provincial environment ministries.