Bosch dryer: the short answer
On a Bosch dryer, a condensate drain that is not clearing most often comes back to condenser and its filters blocked with lint, with drain hose kinked, too high or blocked on a plumbed install the next thing to rule out. Bosch relies on the right consumables and clean filters to reach its rated result; neglect them and the machine underperforms while testing perfectly. The first checks below are owner-safe and need no tools beyond a flashlight; if they come back clean, what is left sits behind a panel and belongs to a technician.
What you are actually seeing
- A full-tank indicator that comes on part way through every cycle
- The cycle stopping early and reporting the tank as full when it is not
- Water sitting in the condenser housing or the base of the machine
- Not this fault: Water on the floor behind the machine — Means: a leak, which follows a different ranking
Ranked for Bosch, most likely first
- Condenser and its filters blocked with lint — Why: Condensate has to run through the condenser to reach the drain path; when lint packs it, the water backs up before it ever reaches the tank. — Owner serviceable: true — Brand note: Bosch relies on the right consumables and clean filters to reach its rated result; neglect them and the machine underperforms while testing perfectly.
- Drain hose kinked, too high or blocked on a plumbed install — Why: A plumbed machine can only lift condensate so far, and a hose above its limit or looped into a trap simply will not clear. — Owner serviceable: true
- Condensate tank not fully seated or its float stuck — Why: The machine reads tank position and level mechanically, so a tank a few millimetres proud reports full and stops the cycle. — Owner serviceable: true
- Sump or condensate channel silted with lint — Why: Fine lint that passes the filters settles in the sump and slows the path long before it blocks it completely. — Owner serviceable: false
- Body: The order below is specific to how Bosch builds this appliance; on another platform the same list ranks differently.
What to check, in this order, and why
- On a Bosch condenser dryer, check the condenser filters and the condensate path before anything electrical — a machine that cannot dispose of its water stops rather than reports. — Why: This one comes first because of how Bosch builds the machine, not because of where the fault ranks.
- Remove the filters and the condenser and hold them to the light. — Why: A condenser you cannot see through will not pass water either.
- Follow the drain hose for kinks and check its height against the standpipe. — Why: A hose above the machine can lift is a fault no part will fix.
The checks you can safely do yourself
- Deep-clean the condenser and filters — Tools: Warm water, a soft brush and a cloth — Time: About twenty-five minutes — Body: Unplug the machine. Open the lower access panel, unlock and withdraw the condenser, and rinse it from both faces until water runs clear through the fins.
- Correct the drain hose — Tools: A hose clamp and a screwdriver — Time: About twenty minutes — Body: Straighten the hose, remove any loop that traps water, and set the standpipe height within the range in the installation instructions. Secure the hose so it cannot fall out or kink again behind the machine.
- Body: Stop at the first step that would need a meter on live terminals.
Before you open anything
Safety
Never defeat a door interlock, a lid switch or a safety thermostat to keep an appliance running. Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off.
Where the owner line ends
Call a technician in any of these situations. the tank, the condenser, the filters and the hose are all clear and the machine still will not drain
The nearest pages to this one
What this page does not cover
This is generalized information for Bosch dryers as a family. It does not carry the model-specific detail — code tables, part numbers tied to a serial range, a chassis-specific procedure — and it defers to any page written for your exact model. Bosch Dryer: Cycle Will Not Finish — Slug: bosch-dryer-cycle-fault — Relation: a different fault on the same appliance Bosch Dryer: Will Not Start — Slug: bosch-dryer-wont-start — Relation: a different fault on the same appliance Bosch Dryer: Noisy or Vibrating — Slug: bosch-dryer-abnormal-noise — Relation: a different fault on the same appliance Bosch Dryer: Door, Latch or Seal — Slug: bosch-dryer-door-seal — Relation: a different fault on the same appliance
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
