Cold air from vents

[jkcharacter]

I have a w124 and all in good condition.

I recently haven’t had time to use it much over the colder months (owned the vehicle since December 2019)
I have now noticed the air vents dont blow out any hot air. I have moved the temperature gauges on both sides and moved the blower position dial as well but no luck.
Any suggestions with this?

 

[Blobcat]

Hello and welcome

Heating valve stuck, would be my guess

 

[jkcharacter]

Thank you for the response. How would I access this to sort it? Bonnet or behind the internal panel? I’m new to this so I would need as much information as possible.
Appreciate the reply

 

[alexanderfoti]

In the bonnet, will look this:

Give them a tap with something hard, whilst the temp wheels are set to max heat. IF you start getting heat they need to be rebuilt (or replaced)

 

[jkcharacter]

In the bonnet, will look this:
View attachment 74044
Give them a tap with something hard, whilst the temp wheels are set to max heat. IF you start getting heat they need to be rebuilt (or replaced)

Yes I located them earlier today after looking online. I will try this tomorrow and report back. Thank you

 

[LostKiwi]

Also check coolant levels and try bleeding the valves to off there is an air lock.

 

[jkcharacter]

Also check coolant levels and try bleeding the valves to off there is an air lock.

How would I do this? Sorry I’m new to this, but I’m extremely practical.

 

[LostKiwi]

Coolant level I'm guessing you know how to do?

To bleed the valves run the engine a couple of minutes then loosen the clamp on the hose from the engine. Carefully slide a small thin screwdriver blade between the hose and valve body. You should get a small amount of water out. Tighten back up.

 

[jkcharacter]

Coolant levels are all good. So the hose from the engine leads too….? I can do the rest if I know which hose to loosen. Appreciate your help with this

 

[LostKiwi]

The valve in the picture posted earlier.

 

[jkcharacter]

The valve in the picture posted earlier.

Ok thanks. I’ll give this a go tomorrow. My first post here but feeling the merc love in this forum

 

[LostKiwi]

The valve has one hose in, two out.
As shown above you can see the inlet hose clearly.
As previously mentioned give it a solid whack first as that's the most likely problem.

 

[DREAMER NO2]

No warm air will comes through the center vents on the W124 ,,Idea is to keep the driver awake on long runs .

 

[mioba]

WHS above, there is no problem

 

[jkcharacter]

Thanks to everyone that replied. I did as lost kiwi said and the heat has returned. Warmed the engine up and tapped on the two circular valves with a rubber mallet. I will see if this has cured the problem but I’m guessing a new part will be required. Hoping it’s relatively easy to fit?

 

[jkcharacter]

In the bonnet, will look this:
View attachment 74044
Give them a tap with something hard, whilst the temp wheels are set to max heat. IF you start getting heat they need to be rebuilt (or replaced)

Thank you for the advice. This has worked and the heat has returned now. I’m guessing a new valve is needed at some point. I gently tapped the valves with the engine up to temperature and the blowers started emitting hot air