How to Disassemble Miele T1 Heatpump Dryer

[brisnat81]

I've recently picked up a second hand Miele WDB130 Heatpump dryer, that is taking way too long to dry and not completely drying. With the earlier generation, the fix has been to remove the front and clean the secondary condenser, that then fixes the issue.

The challenge I have with the T1's is how to remove the front. I can get as far as removing the lid, lift off the control panel and then remove the top two screws. Past that, I'm not sure where to go. The front has to be removed to get the sides off, so the front must come off, I just cant quite see how.

I've tried removing the door hinge and catch screws, but unlike the earlier generations, the front is still firmly attached at that stage. I'm expecting it to lift up or down and then tilt away from the machine, but it doesnt seem to move.

Has anyone removed the front from one of these, can anyone offer any suggestions?

 

[richnz]

Youtube

 

[brisnat81]

Thanks Rich,

I got there in the end, but it turns out mine is new enough that there is no finned condenser grill there like I was expecting. I dont know if that's a generational thing, or if its a model spec thing. They've removed the need to clean it but have replaced the grill with a couple of loops of refrigerant pipe and a much larger fan in the front. It means that unlike the earlier units, you dont ever need to clean it, but it explains why it doesnt fully dry like the earlier units do, it just cant create enough of a temperature differential between the hot and cold side. The older units with a secondary condensor can get items bone dry.

To get the T1's apart, you dont start from the front like you do with the earlier generations. You remove the top and then the sides, most of the servicing can then be done without taking off the front or the rear panel, but you have to remove the sides to pull the front off.

It turns out on mine, that the issue is the condensate pump, it was totally seized. I've managed to free it up and got it draining again, but it's very noisy. To get the condensate pump out, you have to unhook the rear drum bearing and pull the drum, then the condensate pump lifts right out. I didnt need to remove the back or the front to pull the drum.

On the plus side, I paid $60 for the unit and when I rang Miele to order a new pump, they told me that the warranty only expired in November, and it should be covered. So in January they're going to come and do a service call and I'll see if I get it fixed for free.

Thanks again Rich for that video, that would've helped a lot to easily get in there. The grill is on tight and there are three clips on that side that hold it on. Merry Christmas

Nathan

 

[mielerod69]

Miele heat pump

Hi Nathan,

You should keep a look out for the older T8000 series heat pump dryers. I have a T8929WP and wouldn't swap it for a new Miele T1.

I had a Miele T1 heat pump and gave it to my mum as it took longer to dry and the bed sheets would ball up. The T8000 series has two motors, one for the drum and one for the fan, so you get proper reverse tumbling. Also, the T8929 has a gentle tumble option which pauses the drum from rotating whilst the fan is still moving the air through.

I see some of the older Miele heat pumps come up on Facebook marketplace.

Rod

 

[launderess]

"I see some of the older Miele heat pumps come up on Facebook marketplace."

Apparently older model Miele HP dryers can be found at local tip as well.

 

[richnz]

Cleaning the innards

Once a year, I take the plunge and use a garden hose to blast out behind the filter.
Just short bursts and the crud that comes up into the drawer.

We don't use fabric softener but those small fins sure collect dust.

I have a T8000 with 2 motors. There is a cycle for when one uses the rack and the drum does not turn.

Good luck with your dryer Nathan, love a bargain.

 

[henene4]

The old TwinPower heatpump dryers sure were amazing performers.
However, they somewhat shoe-horned a heatpump system in a condenser setup.

Thus they never were terribly efficient (there was an A+++ machine, but that was close to double the A+ versions and took 3h to dry aswell).
But the A+ versions were FAST.

The T1 is more efficient and more cost effective.
Dropping the dual motor set up dropped complexity and price significantly while improving efficiency.
The new inverter motors only use between 100-150W for both drum and fan - the old design used that for just one motor.

There were some of the TwinPower machines that experienced premature compressor failures - which is a death sentence. But that still was very rare.
That design heavily relied on the heat rejector. That's a small heat exchanger behind the ventilation opening on the bottom right with a fan. The heatpump was somewhat oversized for the dryer. That made it fast - but ment the dryer could get run into a situation were the temps across the condensers got to high, pressures rose. Then that fan would turn on and directly reject heat into the room.
If that failed, got clogged or blocked the heatpump could get overloaded leading to early compressor death.

For the dryers I encounter - no matter the brand - I use one of those pressurised pump sprayers you can get a hardware store.

You can set the stream with the nozzle and spray down the condenser every now and then with maybe like a liter of hot water.
The run a quick cycle to drain the condensation collection area from those loosend fluff bits.

Less chance of getting water into the works, a bit more handy to keep around imo.

My mums current Beko came with a brush you are supposed to use to gently brush down the condenser.
It works surprisingly well!

One thing to keep in mind is that the main issue on a heatpump dryer isn't lint buildup interfering with heat transfer - the bigger issue airflow reduction.

The fluff only really gets onto the first inch or so of the condenser.
Afterwards the turbulence has all the big fluff pieces adhere to the surface.
Any particulate matter is so fine it will MOSTLY be washed off by the condensate.

There is currently, to my knowledge, only one heatpump dryer for the home market in the EU that still uses separate motors for process air and motor.

That is under Haiers "Full Reverse" or "1:1 reverse" umbrella.
The model is the TOL Fisher and Paykel heat pump dryer.
It uses basically a tripple inverter (fan, motor and compressor) to get over the efficiency issues.
Appears to be a pretty awesome machine!

I have my VZug T6000 dryer.
That has a typical lint screen in the door, behind that a foam matt and another, different foam mat in front of the condenser.
It has an inverter compressor and inverter motor.
Pretty decent machine with a good bedding cycle though IMO probably not worth the price.

 

[wholelottared]

Reply to #6 (henene4)

Hi henene4, you seem like you're really knowledgeable/informed about the dryers and the differences between them and I was searching for someone like you. My question actually will be off-topic on this thread but I couldn't find a way to message you or email you so i'll write it here.

What are your thoughts on the latest Bosch Home Professional dryers ? I recently bought it (the model code is WTX87EH0TR, I think it's called WTX87E40 and WTX87E90 on Germany). Of course it doesn't have a reverse like any BSH dryer, but I didn't have any problems with it yet. What are your thoughts on my dryer, did I buy a bad device, how are they compared to their older models? For example the condenser never stops until the end (except the AutoClean phase), instead the fan on the front runs sometimes for like 30-40 seconds if it gets too hot. Does this mean it can't control the heat by turning off and on the condenser and uses the fan instead? I would be happy to read a review/thoughts message from you, thank you.

 

[foraloysius]

Here's the link to that Bosch thread.

https://www.automaticwasher.org/cgi-bin/TD/TD-VIEWTHREAD.cgi?92054

 

[henene4]

Actually there are BSH heat pump dryers that can reverse now.
Few models, but they can.

No heatpump dryer I ever used cycled the heatpump except for the AEG Series 9000.

If the heatpump isn't running, there is no drying, since the cold side of the heatpump isn't cooled.
No cold area means no condensation means no drying.
Any time running without the heatpump off is "wasted" time.
The only reason the AEG did it was for situations where there were "damp patches" or mixed loads for moisture to "spread out" throughout the load.

Any HP dryer has a fan to cool the compressor.
Some older designs had that heat dump capability via a small heat exchanger and a cooling fan.
Modern dryers - especially at the A+++ level - have such low power compressors that even if the temperature gets to high, just creating an airflow over the outside of the drum is enough to keep temps in check.
The less heat gets out of the closed drying environment the fast it can dry the more efficient it is.

In the first days, all A++ and later all A+++ dryers were dryers with inverter compressors.
These could vary the compressor power level and thus control heat that way.

My current VZug has an inverter compressor and 2 seperate cooling fans - one for the small heat exchanger in front and one for the compressor.
They can run independently. That's the only way to get full control over the drying performance.

 

[wholelottared]

Reply to #9 (henene4)

Thank you so much @henene4 . I have one last question, are you sure my model uses an inverter compressor? Even though it's A+++ I feel like the compressor always runs on the same power, because it always makes the same noise (no higher or lower) and for example when I run it on Cottons it doesn't get more hotter or anything. Instead, I feel like it controls the heat by the length of the program, for example the duvet program runs for much longer time which creates a higher temperature. Sadly I feel like the compressor doesn't have variable powers depending on the program (if that's what you meant). Is there any ways to check this ? Also, do you know does the Mix program gets less hot compared to Cottons? Thank you.

 

[henene4]

I think you misunderstood

A+++ dryers USED to be inverter compressor machines.
Today, the number of inverter compressor HP dryers on the market is really small.

There is a pretty simple formula today that makes a very efficient and cost effective dryer that reaches A+++.
You need a 400W ish single speed compressor, an inverter motor and a well sealed system. That gives you a usage of about 1.4kWh, a condensation rating of A and a run time of about 2:30h for 8kg under EU regulation testing. You will be blown away how exactly most A+++ machines hit these exact data points.

AEG/ELux and BSH aswell as Acrelik (Beko) have NO inverter compressor machines on the EU market currently.
BSH technically has some in the pipeline, but that is a few years out.

Gorenje, Miele and since recently Samsung have some TOL machines with an inverter compressor.

And LG as an outlier has ONLY inverter compressor machines.

 

[logixx]

"BSH technically has some in the pipeline, but that is a few years out."

Aren't the new models with varioSpeed supposed to launch in March (in der Germany)?

 

[henene4]

Ahm

"Supposed to" is probably the right word - all I can say is that all I know is that nothing internal points towards a 2023 release.

 

[logixx]

The press releases on both the Bosch and Siemens site state March 2023 as the release date of their two new washers and dryers.

 

[wholelottared]

Reply to #11 (henene4)

Thanks @henene4 , yeah I misunderstood. I understand it now though. But I have one more question then. You said the condensation rate should be an A. But on mine it has the B condensation rate, even though it's an A+++ no-inverter compressor model. (WTX87EH0TR, shows B condensation rate on the EU energy label, you can see from Bosch's website too.) How is this possible? And lastly, do you mean that inverter compressor are no longer needed now and they're outdated - or do you mean the companies stopped using it to cut the costs ? For example, does this mean LG uses a more updated technology or more outdated technology right now since they still have the inverter compressors ? Thank you, will be waiting for your reply.

Oh and lastly an another question, from what I understood no-inverter compressors run for the same power throughout the whole program, and it's the same for the all programs right? So all the programs including the “delicate / low heat” actually creates the same heat, is this correct? So does it control the heat it generates by the length of the program? Thanks. If that's the case, it's so stupid that they have programs like delicate and also an option for low heat on all programs.

 

[logixx]

Mine's also an A+++ with B condensation efficiency. Its compressor seems to run at the same speed all the time, venting "excess" heat through the front - kinda like running my central heat on max all the time and opening the window when it gets too hot.

Here's an older model with inverter.

 

[wholelottared]

Reply to #16 (Logixx)

That's really interesting, the video is from 5 years ago. And yeah that's really an inverter condenser because it has different speeds/sounds. Now I wonder what made them stop using inverter condenser if they were using it in the past. Are inverters outdated now and making the condenser run at the same speed a better solution than inverters? I'll never understand BSH even though i'm a fan. I don't think that little fan at the front on ours would be ever enough to control the temperatures, how is it even controlling it if they're not inverter? Are all the programs run in the same temperature? I'm getting more and more confused and I feel like BSH created these recent dryers that we have without even actually thinking/engineering them lol.

One another interesting thing I found is that, the Home Professional models (the one I have) uses a different kind of inverter motor (for the drum, i'm not talking about the condenser this time) and they also have additional parasite filters for the electric. Weird.

The video I saw (translated captions are available):

 

[henene4]

The A condensation rating is one of the ways to do it.

AEG has the B rating with a drying time that's half an hour longer aswell.

Main reason inverter compressors are out of style is cost.
The compressor isn't more expensive, the inverter however is. It's a way higher power inverter compared to what the motor inverters for washers and dryers have to do making them way more expensive to build.