Just a thought. I have recently fitted a new heater matrix but the heating system still doesn't seem to heat the inside of the 110. Does it make any difference which way the the Matrix is plumbed in. There are two water pipes which come out of the heater into the engine block. Does it make any difference which way they are connected up? The top of the water pipes are hot, you can't hold it for very long before you have to let go as its too hot. however during the winter time the heat coming through the heater vents is only luke warm. The unit is sealed and I did clear away any obvious debris like leaves etc. I sealed it back up using pop rivets etc.
One pipe that comes from the engine comes from the front of the engine and goes into the heater nearest the bulkhead. the other hot water pipe comes from the back of the engine and goes into the inlet furthermost away from the bulkhead. Does this sound correct?

I doubt it matters which way round tbh.
I suspect that the flaps are not opening/closing fully OR the foam is poor/missing OR air is getting past the matrix and not all is going through it.
My manky old matrix in a correctly sealed and adjusted heater box will burn my calf.

Cant see the pipe being an issue after all its just a radiator.
As Flossie says go for flap adjustment, you want it so when you put it on heat the cable has a little spring against it to hold the flap tight shut, seconds work to adjust on the heater cable itself.

Don't know about the 200Tdi. The 300 has a water pipe that runs from the front of the engine, between the air manifold and rocker. This pipe goes to the front pipe on the heater box.
As others have said though, I can't see it making much of a difference at all. If you have air coming out of the vents in the cab, and it's cold, then the air must be bypassing the heater matrix. As said that'll be a flap problem and possibly the foam seal.
IIRC to direct the flap to the hot position the heater cable has to 'push' the flap. Cables aren't great in compression! Try operating it by hand under the bonnet, to make sure it's in the right position. Then don't touch the lever in the cab!

Al2O3 said:

Don't know about the 200Tdi. The 300 has a water pipe that runs from the front of the engine, between the air manifold and rocker. This pipe goes to the front pipe on the heater box.
As others have said though, I can't see it making much of a difference at all. If you have air coming out of the vents in the cab, and it's cold, then the air must be bypassing the heater matrix. As said that'll be a flap problem and possibly the foam seal.
IIRC to direct the flap to the hot position the heater cable has to 'push' the flap. Cables aren't great in compression! Try operating it by hand under the bonnet, to make sure it's in the right position. Then don't touch the lever in the cab!

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200 the same set up and I think you will find this is actually the return pipe as the feed is from the back of the cyl head as its the hottest position on the whole engine.

If the water going into the matrix is hot, but there's little in the way of hot air, as above it's most likely you're getting lots of cold air in the mix. If you take the cable off the top of the unit and move it fully over to the left (passenger side) all the air from the fan should pass over the matrix. However, the design is so poor that cold air may still leak past the little steel flap. I found a few bits of camping mat stuck in the right places sorted it - I sealed around the edge of the matrix and completely blocked up the bypass so that air from the fans (I have two) has to go through the matrix. Make sure the seal between the heater and bulkhead is good too.