Miele combi steam oven stops pumping to condensate tray

[groovybug]

Hello everyone,

My neighbour wants to give me his Miele combi steam oven if I can repair it. I have figured out the issue, which is the condensate pump has stopped working for some reason. So at the moment the condensate tray is empty, and condensate water builds up at the bottom of the oven. The warning message "empty the condensate tray" keeps popping up (but the tray itself is empty).

Apart from replacing the condensate pump (which I haven't found for sale anywhere yet), is there any other reason it has stopped working? And is replacing this a DIY-able task?

Thank you.

 

[jj4091]

Model number may help. do you get an error code? Does the pump have a supply voltage to it?

 

[groovybug]

Of course. The model number is DGC5080XL, so it is a combi steam oven. Here is a photo of the pump. Or could this be due to incorrect wiring?

 

[groovybug]

And there is no error code, just warning message "Empty the condensate tray". I guess there is a sensor near the pump that detect this, but the water is in the pump container itself, not on the condensate tray. The tray is empty.

 

[jj4091]

There is on of them on e-bay, https://www.ebay.co.uk/itm/32497730...HaL_rjHPN7qbrI9_nIHp9GcsBF6O-H9hoCpqwQAvD_BwE
Are you sure it is getting a supply to it to make it run.
I get the impression from this user guide that to get rid of the empty condensate tray you simply press OK https://www.eirvik.is/media/4196/dgc5080.pdf

 

[groovybug]

@jj4091
That's the one! Thank you.

I can ignore the message, and the oven still runs, however condensate will just accumulate on the bottom of the oven, without getting pumped into the condensate tray. Its messy to clean up that way.

What do you mean by if "it is getting a supply to it to make it run"? How do I check this?

 

[groovybug]

@jj4091 By the way, the user guide above is for the standard 5080, my one is a 5080XL, it has different condensate tray design. If you are interested, you can see here

 

[jj4091]

@jj4091
That's the one! Thank you.

I can ignore the message, and the oven still runs, however condensate will just accumulate on the bottom of the oven, without getting pumped into the condensate tray. Its messy to clean up that way.

What do you mean by if "it is getting a supply to it to make it run"? How do I check this?

With a multimeter on on voltage setting.
How do you know the pump is not working.Is condensate never pumped up to the tank? Have you checked the pipe work for blockages. Does that valve shown in the video open.

 

[groovybug]

@jj4091 I will get a multimeter and check. I can see the wiring are connected properly though.

I have watched it going through the a circle, it doesn't appear to be doing anything. Condensate does not get pumped up to the tank. It's also very likely the pump itself is blocked due to food debris (similar to how washing machine pump often get blocked). However these pump are so small, I'm not sure I can get to the internals to clean up.

Which valve are you referring to? Please let me know the minute:second in the video. Thanks

 

[jj4091]

The valve at 3min 33secs.

 

[Honj]

This machine does have a service mode which might help with sensor test etc.

1. Switch machine off
2. Press and hold bell button on touchpad
3. Press and release power button
4. Release the bell button on touchpad
5. Immediately press and release the bell button three times and on the third time hold it down until service mode caption appears

Steps above need to be completed within 10 seconds

There's a drain pump test which should help diagnose whether its working - look for component test "M8". Similarly for the drain valve it is "Y26".

 

[groovybug]

@Honj Thank you! Really brilliant guide.

I have been able to test the pump. It works! So it's strange why it's not activated during the process.

And for the drain valve, where is it located? I can hear a ticking sound, but can't see anything actually moving.

(The air valve jj4091 mentioned above, that lets air in at the end of the cycle, does operate normally).

 

[Honj]

Hmm. Hopefully I've not sent you on a wild goose chase, keen to see this appliance saved from the tip .

Drain valve (Y26)
The drain valve Y26 closes the hose under the steam generator. This ensures that water is retained in the steam generator. The drain valve consists of a release element which closes or opens the hose under the steam generator. When the drain valve is switched on, its internal heater is activated. The wax in the release element expands and the hose is opened. When the steam generator is empty, the release element heater is switched off. The wax cools and contracts, and a return spring acts to close the hose. The valve is opened after a power failure in order to remove any water from the steam generator. A complete opening and closing cycle can take up to 8 min.
Part 5 below - probably unrelated to your problem, my mistake for not reading the function description properly!

Drain pump
The drain pump has three water connections. The cavity connection, Fig. 1, Pos. 1, is a direct link to the cavity. This is used to drain off condensate from the cavity. Condensate from the condenser is passed to the drain pump via the condensate trap connection, Fig. 1, Pos. 3. The water level in the pump is registered via a float with a magnet. The magnet closes a reed switch and the pump is activated. Water is then passed via the condensate container connection, Fig. 1, Pos. 2, and a hose to the condensate container (tank model) or direct to the water drain (fixed water connection model).

Need to have a look inside if the pump can be opened up? maybe the float switch is stuck as suggested by food debris. Unlikely to be a wiring fault between the switch and controller... but who knows!

 

[groovybug]

Thank you @Honj . This is so helpful.

You are right, either the float or the reed switch (which is attached to the side of the pump) is the likely candidate. I just need to figure out how to get inside the pump.

However, even after I manually activate the pump (M8 test), the error message "empty the condensate tray" still appears. I wonder what sensor gives this message, as that might lead to the source of the issue. Would you be able to trace it in the service manual for me?

Thank you.

 

[Honj]

Hi,

As far as I can tell there's no sensor that actually detects water in the condensate tray at all. I assume that since the electronics know when and how much water it has pumped into the oven and the fact it hasn't pumped water out (suspected float switch problem) it concludes the condensate tray must be full - or there's a big leak.

I assume also that M8 test does not affect this calculation, especially if the float valve hasn't been triggered at all.

If you do manage to get inside that pump, interested in the results!

Cheers.