Heater Valve Hot?

[DustinNwind]

Hi All,

 

Does your heater/ air vent flapper under the panel get hot? My heater valve is closing completely but it still warms up the flappers under the panel that lets air get into the cabin. 

 

Thanks,

 

D

[Yetti]

There is some hot air that flows to the defrosters all the time.

[DustinNwind]

18 hours ago, Yetti said:

There is some hot air that flows to the defrosters all the time.

So would that heat up the flapper at your knees?

[N201MKTurbo]

There is always airflow through the muffler shroud. the hot air is either directed into the cabin if heat is selected or dumped overboard through the hose to nowhere on the heater box. It stands to reason that the heater box will get hot even if the heater is off. If you open the fresh air vent it should remove most of the heat from the heater box.

[Andy95W]

Dustin- part of it depends on what year M20E you have.  Some early models do not have the overboard dump that Rich was talking about above.  That was added around 1965 or so.

If you do not  have that dump hose, yours is acting normally.  If you do have that dump hose, it sounds like you have a small leak at your valve.  Some of the rubber seals wear out or erode over time.

[takair]

My 64 E has a dump hose.  With heat off, the said flappers do not get hot, but I did have to replace the seals a few years ago.  If you are getting heat in the cabin with the heat off, the. Likely have dried out seals.  You also risk not being able to turn off the heat in case of fire or more importantly CO leaks.

[Yetti]

20 hours ago, DustinNwind said:

So would that heat up the flapper at your knees?

The parts manual has diagrams of the heater flows for various models and year.

[HRM]

Welcome to the vintage Mooney club.

Mine started heating up two annuals ago. I am guessing the seals finally dried up.

[FastTex]

On 11/16/2019 at 7:11 PM, takair said:

My 64 E has a dump hose.  With heat off, the said flappers do not get hot, but I did have to replace the seals a few years ago.  If you are getting heat in the cabin with the heat off, the. Likely have dried out seals.  You also risk not being able to turn off the heat in case of fire or more importantly CO leaks.

Sorry to revive an old thread but this is happening to me now...it sounds like the seals from the knee heat vents are gone. I can feel just the metal valve spinning with the knob on top but, even if closed, I feel hot air coming out. Where did you find the seals? Do you have the part#?

Thanks!

[takair]

49 minutes ago, FastTex said:

Sorry to revive an old thread but this is happening to me now...it sounds like the seals from the knee heat vents are gone. I can feel just the metal valve spinning with the knob on top but, even if closed, I feel hot air coming out. Where did you find the seals? Do you have the part#?

Thanks!

The part that is leaking is on the firewall side.  The part that is reachable by your knee is more of an aiming device and needs to be tightened up.  The valve on the firewall side.....as I recall....I likely used baffle seal material, cut to size.  I wish I would take more pictures when I do this stuff, but I always think I will remember the details...