The short answer
On a machine of this age the leading cause is accumulated scale: narrowed jets and a coated heater, so the wash is neither hot enough nor reaching far enough. Descale it first. A spray arm dragging on a worn bearing is second. Hardened seals and a loaded filter come third, and a tired wash pump last.
What you observe
- Performance has declined slowly over years — Cumulative scale rather than a failed part.
- The upper rack is dirtier than the lower — The upper arm is not reaching or not turning.
- The arm drags rather than spinning freely — A worn bearing at its hub.
- The tub is barely warm at the end of a hot cycle — A heater under a coat of scale.
- NEAR MISS — drops left on plastics — Normal. Plastics hold no heat to dry themselves.
Causes, most likely first on this brand
- Years of scale on the heater and inside the jets — First because every machine of this vintage has had long enough to accumulate it. A coated heater cannot get the water hot and narrowed jets cannot throw it far, and the two together explain a slow decline.
- Spray arm bearing worn, so the arm drags — Second, and specific to age: the hub wears until the arm no longer spins freely, which leaves the upper rack washed by whatever happens to land on it.
- Filter loaded, or its seals hardened — Third: a filter that no longer seats on a hardened seal lets debris past into the pump, and dirty water then recirculates across the whole load.
- Wash pump losing pressure — Last, and the one that decides the machine's future. Its tell is weak spray with clean jets and a free-spinning arm, and the repair cost needs weighing against a replacement.
Check in this order, and why
- Feel whether the tub is genuinely hot at the end — A cool tub points straight at scale on the heater.
- Spin each spray arm by hand with the racks in — Drag here is wear, not loading.
- Hold each arm to the light and look through the jets — Narrowed bores are visible and clearable.
- Pull the filter and check its seal still recovers — Left until here because scale explains more of this.
What an owner can safely check
- Run a descaling cycle with the machine empty — Use a product intended for dishwashers, on the hottest programme.
About 60 min
- Unclip both spray arms and clear every jet — A cocktail stick and a rinse. Check both ends of each arm.
Tools: cocktail stickAbout 30 min
- Spin each arm on its hub and feel for drag — A worn hub is a common and inexpensive part.
About 15 min
- Twist out the filter, rinse it and check its seal — It should press back into shape rather than staying flat.
About 20 min
- STOP HERE if the next step means opening the machine — Pump and heater work sits beside live connections.
Before you open anything
Safety
Unplug the machine or switch off its breaker before reaching into the sump or removing any panel; a capacitor can hold a charge after the power is off. Broken glass ends up in dishwasher filters, so wear gloves and look before reaching. Never run the machine with the filter removed, and never mix a descaler or dishwasher detergent with bleach products in the tub.
When to call a technician
Call when the machine has been descaled, the jets are clear, the arms spin freely and the load still comes out dirty — the wash pump or the heater is then the answer. On a machine of this age ask for the part price before authorising anything, because it often approaches the cost of a replacement. Stop and unplug it if it trips the breaker during a cycle.
Nearest pages of this class
What this page does not cover
This page is written for the brand and the appliance class, not for one family or model line. Where a family- or model-specific page exists for your unit, that page is the more specific answer and you should start there. Deliberately absent: programme temperatures, pump, heater and spray arm part identifiers and fault-code meanings, all of which differ between the integrated, freestanding and slimline families.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
