The short answer
This page covers the BlueStar BS-series dishwasher, the models whose number carries the BS prefix. A BlueStar dishwasher that starts leaving dishes dirty is usually short of one of three things: hot enough water, a clear spray path, or a clean filter. On a pro-style machine with a tall stainless tub the first of those matters more than most owners expect, because a long tub with two arms needs the incoming water to be hot at the start of the cycle rather than halfway through it.
What you observe on these models
- A greasy film rather than grit on everything — Grease is a temperature and detergent problem; grit is a filter and spray problem.
- The top rack washes noticeably worse than the bottom — The upper arm is not being fed, or its feed is fouled where the rack couples to it.
- Baked-on deposits that used to come off — A wash that has become shorter or cooler in effect: temperature, dose or a partly blocked arm.
- NEAR MISS - everything is clean but spotted — Rinse aid and water hardness rather than wash performance.
Causes, most likely first on this family
- A blocked filter and sump — First. Once it fills, the machine recirculates soil through both arms for the whole cycle and everything comes out with a fine grit on it.
- Incoming water not hot enough at the start of the cycle — Second on a tall pro-style tub. Detergent works chemically and it needs temperature to do it; a machine fed the cold standing water from a long pipe run begins the wash at a disadvantage it never recovers.
- The detergent dispenser blocked or opening against an obstruction — Third. A tall item leaning on the dispenser door delays the release, which shows up as grease rather than grit.
- Spray arm jets blocked, or the upper feed fouled — Fourth, and particular to a tall tub: the upper arm depends on a feed that passes the rack, and anything protruding at that point robs the top basket.
- Wash pressure, the diverter or the heating circuit — Last, after the four above have been ruled out, because each of those explains the same symptom for nothing.
- Where this ranking departs from the brand-generic page — The cause that moves is a blocked filter and sump: it leads here because the filter on these models lifts out of the tub floor by hand, so the check that can be completed without running anything comes first.
Check in this order, and why
- Lift out the filter, rinse it and clear the sump beneath — On these models the filter on these models lifts out of the tub floor by hand, so the check that can be completed without running anything comes first, which is why this check leads. Wear gloves - broken glass collects here. What comes out is usually the whole diagnosis.
- Run the nearest hot tap until it is genuinely hot, then start the cycle — It costs a few litres and it removes the single most common reason a good machine washes badly.
- Spin both arms by hand and hold each up to the light — Every jet should pass light, and neither arm should touch anything in the racks through its full sweep.
- Check the dispenser after a cycle for undissolved detergent — Residue left in the cup means the door did not open cleanly, which is a loading habit more often than a fault.
Before you open anything
Safety
Switch the machine off at its breaker before reaching below the tub or moving it - a capacitor can hold a charge after the power is off. A stainless tub holds heat: let it cool before working in the sump after a high-temperature cycle.
When to call a technician
Call when the water arrives hot, the filter is clean, both arms are clear and turning, the dispenser opens freely - and the dishes still come out poorly. What is left is wash pressure, the diverter that alternates the arms, or the heating circuit, and all three are diagnosed with the machine running.
Nearest pages of this class
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
