Megane 1.4 1996 - no heat!

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Mon 11 Oct 2004 17:16
Megane 1.4 1996 - no heat! - Mike H
Since buying the car, I've not used the heater until last week. When I turned it on, the output was barely above the ambient temperature. Yesterday, my mind being focussed by the fact that the mercury is falling fast, I flushed out the cooling system (water and Wynn's system flush) and replaced the thermostat. Although the car now consistently runs warmer, and is obviously better for the work, still no heat. No apparent leaks from inside the car from the heater matrix. The heater return pipe is very hot, the two input pipes less so. I've bled the system thoroughly. There is a change in note from the air system when I turn the heat on via the facia panel, indicating that the flaps in the air distribution box are functioning.

Does anyone have any ideas where the problem might lie before I invest some hard earned cash in taking it in the garage to be fixed?
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Mon 11 Oct 2004 17:23
Megane 1.4 1996 - no heat! - RichardW
Sounds pretty much like the matrix is blocked - presuambly the FEED to the heater is hot and not the return! You could try taking the hoses off at the heater and flushing it (carefully) with a hose pipe to see if you can dislodge the rubbish. After that, it's going to be replacement time. Not sure about Megane specifically, but most modern cars are built around the matrix, and the first job is usually dash out. ££££££

Sell it on a warm day??


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RichardW

Is it illogical? It must be Citroen....
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Mon 11 Oct 2004 17:53
Megane 1.4 1996 - no heat! - Mike H
Richard, understand what you are saying, and it could be true as the coolant that came out was pretty grotty - the crud that came out of the expansion bottle had to be seen to be believed!

However, the workshop manual specifically refers to the bleed screw as being in the heater return pipe, and this pipe certainly gets hot along it's entire length - I'd not expect it to get hot if there was nowhere for the hot water to go as there would be no flow.

I'll take a look at the cooling system diagram in the Haynes manual tonight. I was fearing someone would say it was the matrix as there is rather a lot to dismantle to fix it!
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