Been havinbg a few problems with the Ulysse heating. 2000 2L JDS.

Bought the mpv back in the middle of the year and flushed the system. Dirty, horrible, muddy liquid came out. Gave it a good flushing and all appeared ok, by didn't need the heating on.

Last week discovered the interior heating wasn't working. Felt the matrix, which seems it may have been blocked, also the temperature gauge was fluctuating so suspect thermostat not opening as well.

Got the thermostat out, sure enough not opening. Got a new one. More horrible crud appearing after running it for a bit without the thermostat.

Took the bull by the horns, used some radflush ran it for twenty miles, flushed it, followed by two W5 washing machine descalers tablets. Ran that for thirty miles, top heater pipe starting to get warm now. Flushed out a lot of brown stuff, and then the final effort, three tablets and some soap powder and a run of another thirty miles. Dirty stuff had to be seen to be believed, and flushed till clean.

For the crud removing exercise pretty succesful. Both heater matrix pipes are now balanced as very hot when thoroughly warmed but overall the heat is not that hot and seems to run out of heat if used on full fan.

Anything I am missing? The lever operating the direction of flow of air always seems to be directed towards the dash vents regardless of direction of the lever, but also works on demisting, and at feet level. Can I get to the direction vents without taking the whole dash to pieces ?

Not frustrated yet, done a lot to get this far, but being defeated on the final lap. Any suggestions please.

Hi,
I ran a 1.9 diesel Ulysse for a few years and had a similar problem. I took the heater matrix out and cleaned it. Taking the matrix out is suprisingly easy, but cleaning it took a long time. If you look at the design it is a perfect silt trap and that's what it does, collects all the rust, scale, casting sand, etc. When it's partially blocked, hot water can still circulate in the supply and return pipes, but there is insufficient area of the matrix getting hot to transfer enough heat to the air being blown through it. If I had to do the job again I'd fit a new one without hesitation as they are not that expensive.

Thanks, it appears my work is still not yet done. What do I have to remove to get to the matrix ? I can feel the pipes but the heater seems to be be in behind some plastic bits.

I had to do one in a Volvo years ago and spent several hours working upside down in the footwell with my feet on the seats to get it out.

Don't tell me I have to do that again !

I think you'll be suprised how easy it is to take the matrix out if the 2.0 litre is the same as the 1.9. If you take off the plastic bits you'll see the matrix which if I remember right is held in place by a single bolt. Once you've drained it off and disconnected the pipes it slides out towards the passenger side.

Ok thanks, I will give it a go.