What OVERFLOW Means
WHICH MACHINES THIS APPLIES TO: these are the text-display equivalents of a full condensate tank, and three Asko documents cover them. The Use and Care Guide for the T711 to T781 range prints "Overflow" in the section for the T781, which is the condenser model in that range. The TD70 service manual prints "Over flow fault" for the TD70.2 and TD70.3. The instructions for the TD75 machines, the T408HD and the T608HX, print "Please empty the tank before resuming a cycle" and "Please empty the water tank and clean door filter". Different words, one subject: the water the machine has condensed has nowhere left to go.
WHAT THE TD70 SERVICE MANUAL SAYS THE CONDITION IS: the cause text for the over-flow branch is the same as for the numeric F10 on the same platform - "The microswitch is opened when a full condensed water tank is detected. Detection begins 30 seconds after the program starts. If the microswitch is open >30 seconds the program cycle is stopped." The machine ignores the switch for the first thirty seconds of a programme and then needs it held open for more than thirty seconds before it acts.
THE SOLUTIONS ASKO PRINTS FOR THE T781, QUOTED IN FULL BECAUSE OF THE MEASUREMENT IN THEM: "Clear message by turning the power off then on." / "Make sure the condensed water container is empty. If draining into a drain pipe, make sure the black rubber hose is not kinked or blocked. The drain should not be higher than 40 inches from the floor." / "Make sure the condensation pump is not blocked." That forty-inch figure is a real installation limit. A machine plumbed to a standpipe or a sink trap above that height is asking its pump to lift water further than it was designed to lift it, and the tank fills instead.
WHAT THE TD70.2 MANUAL ADDS FOR THE AUTO-FILTER MACHINES: it attaches four further causes to the same branch - "The auto filter is clogged, defective or the auto filter/sealing is improper fitted", "Defective or improper installed anti-siphon valve", "The reversing valve is clogged or defective" and "Hoses improper installed after service". The last of those is worth reading twice, because it means this message can appear for the first time immediately after a repair.
WHY THE MACHINE STOPS RATHER THAN CARRYING ON: a condensing dryer has to put the water somewhere. If the tank is full and the pump cannot empty it, continuing the cycle means condensing water into a vessel that is already full, and water then finds its way out where it was not meant to.
CLASSIFICATION: normal status when the tank is genuinely full and simply needs emptying. It becomes a fault when the tank is empty, or when it refills immediately, because then the water is not going where it should.
Common Causes of OVERFLOW
- Condensate container full
- Container refitted but not seated fully, so the level switch stays in the full position
- Condensation pump blocked
- Drain hose kinked, blocked, or draining to a point higher than forty inches from the floor
- Float or microswitch that detects the full condition stuck or failed
- On auto-filter TD70.2 machines, a clogged or badly fitted auto filter, a faulty anti-siphon valve, a clogged reversing valve, or hoses refitted incorrectly after service
🔧 One Safe Check You Can Try
Take the condensate container out, empty it, and refit it squarely and fully - a container that is nearly home can hold the level switch in the same position a full one does. On the TD70 machines Asko clears the indication by switching off at the main power switch; on the T781 the printed instruction is to turn the power off and then on. Then run a cycle and see whether it returns. If the machine is plumbed to drain rather than to a container, check the black rubber hose along its run for a kink or a crush point behind the machine, and measure the height of the point it drains into: Asko's limit is forty inches from the floor and a drain above that is the commonest reason a plumbed machine still fills its tank. If the container was not full when the message appeared, or refills within one cycle, the pump or the level detection is the remaining explanation and that is a service matter. If the message started right after the machine was serviced or moved, say so when you call, because the manual names hoses refitted incorrectly as a cause in their own right. Do not take the base or back panel off to look at the pump or the valves: they sit next to the mains wiring, a heat-pump machine also carries a sealed refrigerant circuit behind the same panels, and the machine has to be isolated and drawn out before any of it is reachable.
⚠ Why You Shouldn't Go Further Than That
- Emptying and refitting the container is ordinary use, but the machine is switched off first and the drain hose is only handled when the machine is cool and not running.
- The condensation pump, the float housing and the valves sit in the base next to the mains wiring, so the dryer has to be switched off at the breaker and drawn out before any of it is reachable.
- Heat-pump machines carry a sealed refrigerant circuit behind the same panels, and that circuit is workshop work rather than a check.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.