Did this after I noticed my heat wasn’t hot enough, went from 115 to 163 degrees!!! Another great video!!!!!

Im in the UK . have a clk 320 cabrio 1999. Without your videos i would have to get a bank loan to pay a mechanic for the repairs you do. Thankfully you have a video for every fault mine suffers or sufferd with. Excellent stuff. Pls keep your car it helps me alot when yours goes wrong. LOL

Dude, you absolutely ROCK!!! When I opened the hood on my SLK this morning that valve was sitting right on the right inner fender panel, right out in the open. I electrical tested it and the "left" side didn't make a real click. The right side was a little better but there was clicking. I disassembled the valve EXACTLY like you shoed here and real actuators that you showed on your car were clean but the left side or the drivers control I could hardly get it out of the electrical coil. I got it out and it was full of gunk and gum. I carefully cleaned it and the "right" side valve and reassembled and my AC/Heat system works as good as new. This repair on my car took a total of 30 minutes and I lost just about a half a cup of coolant. I can't thank you enough as I was prepared for a HUGE bill to take this to someone for the repair. But thanks to you this worked as advertised and I can't thank you enough. As another poster said his location I'm in Oregon with a very cold air conditioner now. THANK YOU SO MUCH!!!!

I was amazed with amount of dry leaves laying around the a/c engine and that was making the mouse sound when i was turning on the a/c, I cleared it out and next to it I found the air filter, managed to extract that and it was loads of dust and leaves dried out there. After assembly my a/c works like a charm. no noise and the air flow is strong and smells clean :))) Thanks alot for the tips Fupabox!!!!

Thanks for the video, helped solve my problem here in Brazil

Thanks to videos like this I was able to fix the heater before the mild CA winter. Thank you all.

Thanks. Solved my problem i‘ve had for 2 years.

Thanks for the video. My car does not have dual zone heat, so it has only one solenoid. W124 1995. Your explanation saved me. It turned out the chrome on my piston had failed and it started to stick shut. I found a used solenoid and piston and I have heat. Thanks again

Intermittent A/C with a bunch of codes, took apart the duo valve (as per your instructions) and cleaned the top and bottom plungers/valves with metal polish until they looked like a mirror. A/C back to full function. Mine were fully coated in that gold colored deposit as seen @2:38 - 2:46 Big Thanks fupabox!

Thanks for well explained valve demo it solved my probs this car is parked more less on road .👍👍good luck

Hi Fupabox ? Thanks alot ! your videos are amazing. I am so happy you have a Class :) In a country where mercedez dealers charge US$ 220/hour of labour and black market mechanics charge average of US$ 100/hour your how to Videos are becoming Gifts :) Thanks alot man!!!

Your advice regarding the removal of duo valve helped me to safely remove, clean and put just the way it was and now cold air is coming through just got back from Iraq been off the road for almost two years and guess what started the first time

I have one side heat on my R129, its a 1989 model, at last i found the duo valve buried under the servo, i have heat on one side only, so using your video i will now take another look but first get an overhaul kit, winter is coming ( Nov 2023) and i will need some heat, best regards Cheshire UK

Thanks Fupabox. It really worked. The calefaction of my c230 was not working. I cleaned the duo valve and now working perfect. I save approximately $ 250. Thanks you very much.

Excellent presentation, thank you, I think I'm gonna have to do this job, there is heat coming out on one vent and ac coming out of the other smh

Great video and explaination. I apparently have the left side stuck wide open as all I get is HOT heat and the right side is trying to get cold so maybe the little valve is only partially stuck open. But I gather the system uses the AC all the time and moderates heat in to the cabin as needed. Interesting and simple concept for sure.. Appreciate the video.

Thankyou so much, I've had four w124 estates they all ended up with this problem, I followed your instructions cleaned all the components, put it all back, instantly my heating works like a brand new car, the only other problem on my 93 300td is central locking not working on drivers door, when it works, if I lock from the passenger door, if you have a film on that you'd be a super star

Thanks! I found out this morning while opening the piece. Not that much junk in the housing that stays in the car, but the plungers and all the other parts cleaned up; little but stuck thin "crusts...." Hope it will work again! Thanks again for the great video!!!

Great video clear picture and sound..

Awesome job, i much prefer watching your videos to Mercedessource, I do like that you are precise, educated and polite, you must be Canadian.

excellent ez fix 220e w124 thanks for the vid

Well done video and explanation. Thank you for posting !

thnaks, it was very helpfull for me

Hi! Thanks for the tip! i looked under the dashboard on passenger side and after un-screwing 3 bolts it lead me to where the aircondition fan is. Godness,

Thanks friend clean it as you indicated in your video and now warm very well greetings

Perfect helpful video. Thank you.

From UK , thanks 🙏 v helpful and £ saving

Awesome i have a w202 2000 merc c180! so ill now check if mines duo valve and see if it needed cleaning! (probably as the heating seems to be a bit slow) :D

Well, I did unplugged but nothing...no warm water is passing... My duovalve is an expensive one because of my auxiliary heater system, and hard to find on SH spare parts. I will open again, and I will pull out that plungers, so the water can pass this duovalve. Thank you sir for your help!

Making working on my W202 easy.

Thanks Fupabox for all the videos you make, several of them have helped me when working on my 1999 c280. I was wondering if you had any idea of what could cause a knocking noise behind the dash when the a/c is running. It sounds as if it is coming from the passenger side behind the dash.

I had an issue on my w221 where only side of the rear would get ac. It turned out to be this unit. It is revised in the w221's but same design principle. Nice video. I ended up just replacing mine. Yer right it is a bitch to reconnect the hoses. I had to use 3 hose clamps to clamp each hose or you lose a ton of coolant unhooking the hoses

Nice quick vid. I just wanted to add on my plungers that pull up into the solenoids mine were stuck in the solenoids. I took some 1000 grit sandpaper lightly sanded to remove the old goop and residue, and cleaned the inside of the solenoids with some maf cleaner, just to remove the old goop. All good works like new.

Thanks for the video. On my Mercedes the heating is working fine. However, the cooling is not working. Are these 2 valves related to the cooling system?

wow you love your duo valve

Estou em portugal e queriam levar-me 400€ pois diziam que precisava de novo. Limpei como ensinou e ficou OK. Muito obrigado.

The Duovalve plungers are available on Ebay, and new, and that included the rubber gasket. Mine came from Russia.

Nice one!

Hi! Great video!!! I only wonder where did you leave the connector, mounted with 4 cupper wires on the coils?

Been wondering why it blows cold on the driver's side(the temps are set to MAX on both sides)... Tonight my side of the windshield fogged up really bad and I had to drop the temp on the passenger's side. I hope this clean-up can solve the issue :D

Interessant

Hello, I have a SLK 230, 1998 ... my heater works intermittently. i tried to open the duo valve and it looked like some kind a oil was coming out so i put the screw back...i don't know if i should open it and clean the valve.

Now a small question for you.. My car (Mercedez C180 1998) make some crazy noise when i turn the AC on. sometimes its like you hear a mouse running inside the dashboard from driver side to passenger side. also recently i turn the AC on, but instead of cold air I get warm heated air .. i wonder if you have any idea what could possibily be the issue? Appreciate any tips. Thanks Jay

Very excellent video my heat work very good thanks for doing this video.

thank you!

Amazing video,thank you. Do they affect AC coolness if they are defective? I have a mono valve. Thanks again

hello fupabox, I just saw your video. does this affect the unstable RPM drop

Your video shows the entire process except when you initially first take off the Dual valve cover the video cuts and then you already have the rods with the Springs out how do you get those out

I wonder if anyone could help: My air blows only hot in an R129. The monovalve ticks every couple seconds (if key is in position II, engine off, I can hear the ticks). I heard the valve is supposed to click/clunk loudly once. Would taking my valve apart be the next step, or is it a vacuum issue?

hey man thanks for your videos they're so helpful. and in my case when i turn the temp wheel to hot i'm not having very hot air and it's coming out only from my side vents,is it normal or it should come out of the center vent too? and could it be only this valve or maybe a clogged heater core? if yes can i flush it after disassembling the valve? and my other question is when i turn on the fan it takes time to start running is it a bad fan motor or resistor or it normally operates like that. appreciate your help :)

that solenoid check made things easy

I have no heat on my w124. The hose going to to the monovalve is warm, and the valve itself is. the hose that goes to the cabin or beater core is cool to touch. think it's a clogged beater core? also, can flushing it with a garden hose hurt anything?

great info, except on my car there's no room to get your fingers to disconnect the electrical plug, or much room for anything else

I got the same issue and I'm also planning to get it fix. I'm thinking of doing this during the weekend. Just want to know when you clean your driver side valve. What is the tools or what do you need to clean? Fiber cloth or any cloth can do the job?

thank you

is this what we actually control when we select temperature inside the car?

@fupabox sorry, it's normal that my central vent has only cold and ac air? And no warm air?

Following the instruction, the only thing that was different, is the area where the brass needle valves are seated was full of anti freeze. I tried to get the anti freeze out using paper towels to soak it up, but it just kept filling with anti freeze. I wanted to be sure that the needle seats were in good shape. Any idea why it kept filling up with anti freeze? Your video showed them dry?

'99 C280. The hose that connects to that, that goes down to the engine at the bottom sometimes pulsates like a heart beat. I also sometimes hear a pretty loud flap door closing under the dash glove compartment are. Any ideas?

Hello, Would you care to guess why the front defroster in my wife's '98 C230 goes to full hot when activated? The fan speed, which goes to full speed can be lowered manually, but the temperature can not. Even at low speed, the interior of the car gets WAY too warm after a short while. The A/C doesn't seem to work very well either, as if the control unit has a mind of it's own...could it be that (the control module in the dash)? Thank you!

Hi fupabox. I have a another nightmare problem with my CLK 200 kompressor, 163 HP engine M111.344 . Automatic 2 zone AC . Only one big cooling E-fan. The problem is that the electric cooling fan goes occasionally to full speed at random intervals but the engine is for example cold and the air vent flaps open and close in random manner. As soon as I turn OFF the AC/heater unit altogether the cooling fan works normally, and kicks in at about 85 C temperature. AC error codes are B1459 and B1423, B1416 (416 is the aux cooling pump and is not related to the problem because its not working for 2 years, carbon brushes worn out) . It seems as a problem with Y11 switch over valve or a short circurt. I can erase the code but they are coming back. Can I perform a vacuum test ? The air flaps are working fine. Another OBD scanner shows B1100 and B112E code. Just a side note. While replacing the camshaft magnet I broke of the cooling temperature sensor (only the plastic connector broke but the pins where OK so i just used crazy glue to fix it). Might this be the culprit of the problem ? The temperature gauge however shows the correct temperature so I assume its working fine. I also noted a few knocks from the left duo valve for a coupe of seconds upon startup. Temperature hot cold is working OK for both zones. Should i clean and check it anyways ? How can i test and troubleshoot the problem ? Please help . BR

wow, i just found your video and how timely is this. I have no heat and my mechanic told me that it would cost over $500 just for the replacement valve. I went out and took a look at the assembly. I unplugged it and didn't really hear any clicking, but when I went to plug it back in, I discovered that the unit started "whirring" (for lack of a better term) like it was kicking in. But it is only for a short time and then stops. Do you think this is worth a cleaning, or because I did not hear any clicking should I just look to replace it? Thanks so much!

This would not prevent my blower motor and climate control from turning on right? It turns on sometimes after an hour when the car is warm...after the recirculation switch clicks and blinks for a few minutes....

Hi, the shaft of my plungers have broken. Is it the shaft of the plungers that comes up and down sliding in the other shaft or ar they magnetized and come up and down with the shaft of the coil, that brings them up and down? Because if they come up and down with the shaft of the coil I can glue them. Thanks

Hello sir. I have a problem with my duovalve from my '01 E-class. Is very similar with the one you have on your car. My duovalve is clicking when is on cold vent, but it seems like I don't have any heat in my car. I opened my duovalve and anything seems just fine, but again is no heat in my car.Is posibly not to open that plugers because of that springs? Any ideea? Can you help me please? Thx.

On my 1998 SLK230 there is no clicking when I connect and disconnect the wires. Do you know which fuss to check? The right heater vent is stuck in the on position so it blow hot air as soon as the engine heats up after about a minute, even if I have the a/c on for the left vent.

I have a question w208 clk 320 my ac clutch kicks on blows hot air put can with recharge gage attached say it over charge so I release the pressure keep releasing till compressor stops put can back to gage says low but when u try ti put charge back in it shoots to red with barley squeezing the release I'm stumped what to please help of possible

Hi. I have different problem on my w124, no AC. It only blows hot air. There is aprox 14v on pins when set temp to minimum, valves are clicking. When to max they are not clicking and no voltage. So electrically is fine. Plungers are not broken, only a bit rounded on the "heads". everything cleaned. Where is the problem?

Where is located in the ml430 w163?

Mine were at cold on the passenger side, now is at heat but can't get it back to cool again.

well I unscrewed it but it refused to be taken apart it was so gummed up and the gasket was toasted so I bought a used one and replaced it and now im getting hotter air than before. it's a bit hard to work on but it can be done

Ive got a 230 and i have large volumes of heat that comes out of passenger side defrost but little to no air out of drivers side. Help!! What do yall think?

Dear friend, if I remove this valve, no need to have hot air in the car, here in Brazil is very hot, if I remove the valve and close the hoses have a problem? Because water passes through them. Thank U

my c230 is heating up inside when driving what could be the. In summer it gets very hot please help.

Hi there, bro. After going through diagnosis, the code that appeared was B1416, the circulation pump. So I got across your vid and did the step by step cleaning. However, the same code remained when I diagnosed it again and after I tried to delete it. It just comes back. I notice that the duovalve on my CLK 320 '97 is heating up but I can still touch it coz it doesn't burn really. But is it normal for the duovalve to heat up even when the car/engine is not running at all? Also, maybe you can help, these are the values I got from the sensors: 1- 30 2- 40 3 -23 4- 23 5- 67 6- 83 7- 12 8- 53 It appears that my evaporator temp sensor is faulty (#5) because it shows very high temp at degrees C. Are these two (sensor and circulation pump) connected or something that my compressor shuts off after a few minutes? Thanks friend.

hello futabox, i've got an 1990 w124 230e and i've got the following problem: the ceter vents, the one on the right and the bottom ones on both sides blow just cold air. the only one blowing warm air is the vent on the left. could this problem be solved by cleaning the duovalve? what could also be possible? thanks a lot!

Do you refer lubricate with some coolant are you referring just water?

Hey Fupa, I tried your trick in disconnecting and connecting the wire to hear the magnetic thingy reacting. I didn't hear anything, I think its a fuse issue, any idea which fuses are responsible for powering the duo valve?

thanks🙏

Silly question but on a 2002 S430 where is this valve located?

After I did this, cleaned everything off nothing was broken. Reassembled everything and now its leaking when the car gets to running temperature. Seal as well as the plungers are seated properly and the actuators are working.. Thinking of sealing it with gasket maker or something at this point

Hi My w210 /99 has an ac problem.I'm unable to switch the air inside and outside. I always get the outside air with all bad smell from outside

hello, what would you use to clean if they are dirty? q tip?

I have just come across another issue electric radiator cooling fan failure. is there any way I can wire and electric fan to the radiator my old one has had its says as well as the resistor I've checked the radiator fan switch the voltage stays at 7. Something something now j know thus much for sure when the temp reaches 80 degrees ecu is supposed to rein put power into 12 volts thus activating fan which it isn't I'm prepared to do the wiring just wanted an advice so perhaps u could email me or better yet a video to boost confidence is appreciated

I have problem with my mercedes w203 c200 cdi year 2001. When I put on a/c have cold air only on passenger side to driver side I have a hot air. What can be the problem? Thank you

Hi, I have a 94 S420 and hot air is constantly blowing out from the side and front window vents. My core and valves look a little different.... would you recommend taking them apart and cleaning? Do you, or anyone else, know of any rebuild kits for the core+valves on my 94 s420. Thank you and GREAT VIDEO!!!!!!!!

I have a 1998 c 280 and when i drive and press the gas my center air conditioners stop blowing then come back on in like 3 to 5 mins. Could u tell me if thats normal or is something wrong

Great Video I have an 89 E Class exactly the same DV as yours. I can hear my duo Valve inside the cabin though and its driving me mad :( Solenoids click as they should and my heat works as it should but surely I should on hear the clicking under the bonnet not inside the car :( Need a solution as the noise is quite literally driving me around the bend!

Is coming warm water from engine to that duovalve, but is not passing . The duovalve is getting warm too but, the hoses coming out are cold...

Hello Futabox, just baught a 1998 c230, i'm having a problem with not enough heat coming out. Does cleaning these valves could solve this problem or the thermostat can alson be a problem? Thank in advance..

Hey with this setup I see the connector has 3 connectors coming from 4. I took apart the duo valve unit from my 99 clk320. I never heard click sound so before i consider buying a replacement i want to be sure there is no problem with the connector. Can I use a normal live wire detector? (Looks like screwdriver with bulb in it and tip is + while wire coming from head/back of handle has a clip for -)

I remove my duo valve. The metal plate was hard to remove but I got it. Everything looked good and was clean. I reassemble the duo valve and now I have a leak and the back left screw seems to be stripped because it's not tighten. Do I need to try and reassemble the duo valve or the replace the screw? Any advice??Thanks

Have you ever done an output shaft seal on 2000 w202?

Nice video. Why are there 2 valves? One for the right side, one for the left? I have no cold air only on the right side on my car, is it possible that only one valve is sticking or blocked? In which position is the plunger letting hot coolant pass : when it is in up position our down position (rest position is???)? Thanks to anyone who would happen to know! Cheers

What if I clean it out and nothing is broke and I still don’t have heat

hello my car is w202 c280 it had no heat I cleaned these valve after that was good.So now its always blow hot air if I switch on air conditioner still hot .when I open engine aircon is running but theres no aircon inside only hot air comes out please help I'm stressed.

how block the duovalve , since i at malaysia.

Where is this clamp 180?

When I unplugged duovalve I only have cold air when plugged in I only have cold air. What's going on? I changed the duo valve since I thought it was bad but nothing changed. Any recommendations?

Hi fupabox, im a newbie just got a w124 e320 1995. My a/c is blowing cold air in the center and hot in the right and left vents, under too. Is it possible the duovalve is clogged? is it not working? thank you .