Daniel Mitchell Key Takeaways
- F78 on a Miele dryer means the condensate cannot be pumped to the container or the external drain.
- The cause is one link in a short chain: container, pump, float switch or drain hose; each can be tested separately.
- A full container is the cheapest cause; emptying and cleaning it, and the float switch, comes before any repair.
- Fixing is almost always the answer; replacing makes sense only on an old dryer with other major faults or a second big repair in two years.
- If water reaches the floor or the pump makes no sound, stop using the dryer until a technician has looked at it.
The Bottom Line
Empty and clean the container and float switch, check the hose and cut the power for five minutes. If F78 returns, the pump, switch or an internal hose is the fault, which is a repair, not a reason to replace the dryer. The price is confirmed after diagnosis, with a written estimate before work begins.
When F78 appears on a Miele dryer, the Miele dryer condensate drainage fix or replace choice almost always lands on fix. The code means the dryer cannot move the water it takes out of the laundry, and that is a plumbing-sized problem, not a failure of the machine's heart. This guide is about that one system, the pump, the container and the drain path. For the whole-dryer decision, with age bands and energy savings, read our guide on Miele tumble dryer repair vs replace first.
| What you find | Fix or replace? | Why |
|---|---|---|
| Container was full, empty and clean now | Neither, it was only full | Emptying the container resolves the code |
| Drain hose kinked or blocked | Fix | Straightening or flushing the hose restores flow |
| Float switch stuck with lint | Fix | The switch has to move freely; cleaning may be enough |
| Pump motor failed or silent | Fix | A single part in a machine that is otherwise sound |
| Water already in the base, machine over 12 years old | Weigh it | The age rules in the section below apply |
| F78 on top of a second major fault | Lean to replace | A second major repair in two years points to decline |
Should You Fix or Replace a Dryer With F78?
Fix it, in nearly every case. The F78 page describes the code as a condensation drainage problem: the condensate cannot be pumped to the collection container or the external drain. It lists a typical repair from $120 and a professional repair time of 20 minutes to an hour and a half, which makes it one of the lighter jobs on a Miele dryer. The final price is confirmed after diagnosis on site, with a written estimate before any work begins.
The case for replacing only arrives when F78 is not the real story: a machine that is old and has other major faults, or a second expensive repair in two years. A single pump or float switch on a sound dryer is not a reason to buy a new one.
It also helps to think about what a replacement would cost you in other ways. A new dryer means paying to have the old one removed, settling a new machine into the same space and learning its programs, all to avoid a repair that takes between 20 minutes and an hour and a half. Weigh that against the age and history of the machine, not against the code alone.
Where the Water Goes
A condensing dryer does not vent steam outside. It cools the damp air from the drum, turns the moisture back into water and has to put that water somewhere. The sketch below is a simplified path, not your model's exact plumbing, but it shows which part a given symptom is pointing at.
F78 is raised when the pump stage cannot do its job. That is why the page lists the container, the pump, the float switch and the drain hose as separate causes: each is one link in the chain, and each can be tested on its own.
What Can You Check Before Paying for a Repair?
Five things, all outside the cabinet, and all taken from the F78 page. Start at the container, because a full one is the cheapest cause by far.
- Empty the container. Remove it and empty it. The page says to do this before every cycle.
- Clean the container and the float switch. Rinse it and check the small lever or ball for lint or debris. The float switch must move freely.
- Check the drain connection. If the dryer is plumbed to an external drain, make sure the hose is not kinked or blocked, and flush it with water to test flow.
- Cut the power for five minutes. The pump controller may need to reinitialize.
- Listen for the pump. During a cycle the condensate pump should run periodically. No pump sound means pump failure or no power to the pump.
If the code clears after the container and float switch are clean, there was nothing to repair. If it returns within a cycle or two, the checks have done their job: they have ruled out the cheap causes, and the technician starts from a shorter list.
When Does F78 Mean a Real Repair?
When the container is empty and clean, the hose is clear and the code still returns. At that point the page lists three conditions for a technician: the pump motor has failed, the float switch is stuck, or an internal hose is blocked. All three sit inside the machine, where an owner should not go. The same applies while the dryer is still under warranty, since the repair then belongs with the warranty.
- Pump motor failed. The pump is not running during the cycle, and the container stays empty.
- Float switch stuck. The container-full sensor does not move, so the board reads the wrong state.
- Internal hose blocked. Water cannot pass inside the machine, even though the external hose is clear.
Two signs make the visit urgent. Water leaking onto the floor means the condensate is escaping the system, and a pump that makes no sound at all means it is not working. The page lists both under stop immediately. The related symptoms of water collecting in the base and poor drying performance have the same root, because without condensate removal, drying efficiency drops.
The Age Rules That Decide Replace
The repair-or-replace guide for Miele dryers gives a short sequence of questions. Apply it to the machine, not to the pump.
- Under 8 years old. Almost always repair. The dryer is in its prime.
- 8 to 12 years old. Repair if the cost is under half the price of a new equivalent model. A drainage repair easily passes.
- Over 12 years old. Repair only simple fixes. A pump or float switch is simple; a failed compressor on a heat pump model is the kind of fault that moves the answer.
- Second major repair in two years. Replace regardless of age.
That last rule is the one to watch. If F78 arrives a few months after another large repair, the machine is showing a pattern, and the drainage fix is the small part of a bigger decision.
Can You Keep Using the Dryer While You Decide?
Maybe, and only after emptying the container. The F78 page says that if the container was simply full, emptying it resolves the issue, but that if the pump has failed, continued use may cause water to accumulate in the base. So run it only if emptying the container clears the code, and stop if you see water on the floor or hear no pump during the cycle.
Our dryer repair service covers the pump, the float switch and the hoses, and the tumble dryer repair costs guide has the full price table for the other parts. Because the checks above cost nothing, do them first; then schedule a visit or contact us with the code, what the container looks like after a cycle and the age of the machine.