IAN MAC
Senior Member
When looking for this valve, what exactly am i looking for, whats attached to it. Heater blowing hot and cold whenever it likes and seen this mentioned before. Any other tips most welcome.
Duo / Mono Valve
- Thread starter IAN MAC
- Start date
Hibbo
Senior Member
The duo valve will have one 3 hoses connected to it. One from the engine (supplying the hot coolant) and two going from it through the bulkhead to the heater matrix.
Parrot of Denial did a good HowTo about them with good pictures, search for that so you can see what you're looking for.
It sounds as though the cabin temp sensor isn't working properly, so the heater can't compare the actual temp to the set temp. On the w124 there's a little vent up in the interior light/sunroof switch bit in the roof that sucks cabin air in to detect the temp. If this gets clogged up with fluff etc this can cause the heater to malfunction.
Hope this helps a bit.
Parrot of Denial
did a good HowTo about them with good pictures, search for that so you can see what you're looking for.It sounds as though the cabin temp sensor isn't working properly, so the heater can't compare the actual temp to the set temp. On the w124 there's a little vent up in the interior light/sunroof switch bit in the roof that sucks cabin air in to detect the temp. If this gets clogged up with fluff etc this can cause the heater to malfunction.
Hope this helps a bit.
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