Mercedes-Benz Forum banner

1 - 6 of 6 Posts

·
Registered
Mercedes Viano 2.2 Ambiente
Joined
·
9 Posts
Discussion Starter #1
Hi folks, have searched the forum for an answer, but can't quite find one that meets the following criteria:

Viano 2.2 diesel 2007 front heater does not work.
Rear heater does work.
Front fan/blower does work.
Aircon works.
Recirculation Button works.
All of the instrument panel works except no hot air or temperature adjustment in front of vehicle only.
Has happened since I have fitted a new alternator. (may have nothing to do with the problem)
All fuses under the bonnet checked, aok.

What's the verdict folks?:confused:
 

·
Registered
Mercedes Viano 2.2 Ambiente
Joined
·
9 Posts
Discussion Starter #3
Solution

I found out the problem myself in the end. The water hose that comes out of the heater goes to a motorised valve. There are 3 wires that are connected to this valve. Mine had somehow been severed. Not sure how, bit of a mystery. Once reconnected, heater works fine again. First check you have hot water going to the heater. Is on the passenger side bullhead. There is a T in the hot feed pipe, one end goes to the rear of the vehicle, the other to the front. Check that is hot first. If it is not, you may well have an airlock. Then check the pipe that exits from the heater. If it is cold, you may well have the same problem as me, or have an airlock.
The motorised valve/solenoid is on the inner wing, at 90 degrees to the heater pipes on the passenger side. Good luck!:thumbsup:
 

·
Registered
Joined
·
4 Posts
Hi there, thanks for the quick reply. When you say passenger bulkhead did you remove the dash or is it in the footwell? Also how did you get to the motorised valve in the wing - engine compartment is pretty packed. Did you take out the fuse box? Final thing, where exactly is the heater? I've taken off the top cubby and controls facia so can see the motor (i think) and assume the heater matrix in under it inside the dash but not 100% sure. Cheers
 

·
Registered
Mercedes Viano 2.2 Ambiente
Joined
·
9 Posts
Discussion Starter #5
Hello - No need to remove dash or foot well, though the heater is in the passenger foot well to the right hand side. It has a black plastic cover on it and you may just be able to see the metal entry pipe without removing anything at all. You will see it only if you use a torch.
To check the temp of the pipes you need to check from the engine compartment. Passenger side, you can see the pipes going in and out of the bulkhead. And the motorised valved is to the right hand side of that, attached to the inner wing. No need to remove anything at all. Just gently push any hoses aside to reveal the solenoid. It is below the fuse box. The solenoid is made of black plastic with a hose attached to each end and part of the wiring loom (black wrapped) goes to it also.
 

·
Registered
Mercedes Viano 2.2 Ambiente
Joined
·
9 Posts
Discussion Starter #6
Sorry, might not have explained myself too well. The T in the hoses is in the engine compartment, passenger side. It tees off and goes immediately into the bulkhead and into the heater. The hose to the heater is only a few inches long. The exit hose from the heater is 2/3 inches next to it. The other exit of the T goes down the bulkhead and to the rear of the vehicle.You can see the T and check for hot/cold hoses from the engine bay without moving anything at all. No need to go into the foot well at all other than to be inquisitive like me:rolleyes:
 
1 - 6 of 6 Posts
Top