Hi all! Happy New Year to everyone!
It didn’t start very well for my ’86 360 GLE, though; the other day, I turned the engine, and after a while, noticed I have no heating anymore! Luckily, the winter has been very mild so far, but the idea of having no heating doesn’t bring a smile to my face!
The fan is working normally, at all 3 speeds, there’s just no warm air entering the cabin. The slider is fully in the warm (red) field, mind you... The strength of the air flow is also normal, as usually. Following the instruction from the previous topics about similar problem, I disassembled the front panel of the heater, and cleaned the famous bimetal clip, made sure both surfaces are shiny and making contact. I also cleaned the rubbish that has deposited onto the heater grill (not that it was important, but I did it while I was at it), and warmed up the engine in hope of any improvement, but nothing. Is it possible that the heater itself has gone? Any other things that could have gone bad? Or shall I just wait for the summer?!
I don’t know if that’s important, but I noticed that the heating slider has been a bit stiff to push into the warm field recently. Does that indicate any fault?

Hello, have you tried disconnecting the heater and flushing it through with a hose pipe in both directions? This should work wonders to remove any sludge or air lock, or at least it has on my old cars! It could also be a block or break in the heater valve itself - perhaps its jammed if the lever is difficult to move. I would check that the cable still operates it OK. You can still get new heater valves from volvo, or at least I got one about a year ago. I hope some of this helps.

If the slider has got stiff, check the cable hasn't bent, as once it bends, it doesn't work any more. You can see the tap the cable connects to at the windscreen side of the engine, in the hose that runs to the matrix, you can try turning the tap by hand, see if this makes a difference.

In my car the heater tap had so much corrosion stuck inside it that it jammed it open, butcompletely blocked, so no water flowed thru it, and no heat came out, the cable from the slider just popped off it when you tried to move it.