Lack of heat to windscreen

[Woody]

Hi all, apologies if this has previously been asked, I did have a quick look prior to starting a new topic...

The heating to my feet in my mk 3 Marina is perfect - however in these colder months I've noticed that I get luke warm air to the passenger side of the windscreen and ice cold air blowing up on the drivers side even when the heat setting selector is on maximim heat.

With the direction selector on the windscreen I do still get a bit of warm air at my feet which as I say is really quite hot, but strange how the air the windscreen is luke warm on the passenger side and then cold on my side!

Just wondered if anyone has any experience of this or what I can do to remedy this?

Many thanks.

[MarinaCoupe]

The central heater matrix and blower feeds into a plenum which has 4 outlets, each one has a stiff convoluted plastic hose, two run to the windscreen vents and two to the vents on the ends of the dashboard. They can dislodge themselves from either end, or may have been dislodged if someone has been inside to fit/adjust a radio or if they have had the dial pack out.

Checking can be easily done by using the selfie video function on a smart phone, with the flash light/torch on.

[Woody]

Many thanks Chris, that’s this weekends task then!

[MARINAMADBAZ]

On the heater box the bottom flap that supplys heat to the floor or top vents has a foam sealing strip on it normally disappears with old age meaning that the flap always let's air to the floor weather in top or bottom portion on the slider if you replace thus you should then get morr air force to the top vents
Also heater matrix can get blocked the feed pipes are on the left hand side of the matrix meaning that the drivers side gets blocked as the water finds its easiest way out again
Try flushing heater matrix normal flush and reverse flush this may help restore more heat to the driver side
Carefully pull the heater feed pipes of in the engine bay
I connect some spare hose onto these and connect a hose pipe
I have also left a heater box matrix filled with coca cola in to help clear clogged box over a few days (you've seen what it does to a coin)again using spare hosing and binging the ends up with a bolt.
As Chris said check all heater box interior pipes for splits or badly fitting for air escsping from the heater box
Only other thing check heater pipes are getting hot feed and return from engine
Check thermostat on there is 3 thermostats available
A 74c
A 82c
A 88 c
Thec74c is for a hot climate
The 82c us standard
The 88c is winter use

Hope this helps

[Woody]

That’s fab, thanks matey!