PA 28 Warrior floor heat duct question

[Tom Jackson]

It seems as though the shut-off valve for the heater system is only
controlling the passenger-side heat duct on the floor of my '74 Warrior.

The pilot's side is hot to the touch, whereas the passenger side is
relatively cool to the touch. I can shut the small pilot-side floor vent so
the hot air doesn't come in the cabin, but the hot air inside the duct heats
it to a point where it makes my feet warm.

It seems as though this floor has some sort of divider running through it.

The main control valve (that apparently controls the overall flow of hot air
to the cabin through this duct) is in the engine compartment. I have taken
off the main hose that comes from the heat exchanger and felt inside this
control box. It feels as though there is a large flap-type valve, and it
appears to be fully closed (at least that is what it feels like.) I am not
sure if this valve is also split? I cannot feel far enough inside the unit
to be sure.

Does any of this make sense? Ideas for how to correct it?

Thanks.

[John Kunkel]

"Tom Jackson" > wrote in message
news:%Qi3d.70295$MQ5.5650@attbi_s52...
> It seems as though the shut-off valve for the heater system is only
> controlling the passenger-side heat duct on the floor of my '74 Warrior.
>
> The pilot's side is hot to the touch, whereas the passenger side is
> relatively cool to the touch. I can shut the small pilot-side floor vent
so
> the hot air doesn't come in the cabin, but the hot air inside the duct
heats
> it to a point where it makes my feet warm.
>
> It seems as though this floor has some sort of divider running through it.
>
> The main control valve (that apparently controls the overall flow of hot
air
> to the cabin through this duct) is in the engine compartment. I have
taken
> off the main hose that comes from the heat exchanger and felt inside this
> control box. It feels as though there is a large flap-type valve, and it
> appears to be fully closed (at least that is what it feels like.) I am
not
> sure if this valve is also split? I cannot feel far enough inside the
unit
> to be sure.

The control valve on the firewall feeds a distribution box that should send
the warm air to both cabin heat ducts equally, the cabin ducts have a
divider to divert some heat to the rear seats. The seal on the flapper valve
may be deteriorated and allowing heat to pass through in the closed position
but that doesn't explain why there is hot air on one side only.

If the panel heat control is fully open does warm air flow from the
passenger side?

[Tom Jackson]

Good question, I'll have to check that out (passenger-side heat when "on".)

Regarding the rear seat area, I don't think there are any vents back there?

Are you indicating that perhaps, the main valve is leaking thus causing heat
to come down the pilot side, but there may be a restriction on the side that
feeds to the rear (i.e. passenger side?)

"John Kunkel" > wrote in message
news:wDj3d.223777$mD.183705@attbi_s02...
>
>
>
> "Tom Jackson" > wrote in message
> news:%Qi3d.70295$MQ5.5650@attbi_s52...
>> It seems as though the shut-off valve for the heater system is only
>> controlling the passenger-side heat duct on the floor of my '74 Warrior.
>>
>> The pilot's side is hot to the touch, whereas the passenger side is
>> relatively cool to the touch. I can shut the small pilot-side floor vent
> so
>> the hot air doesn't come in the cabin, but the hot air inside the duct
> heats
>> it to a point where it makes my feet warm.
>>
>> It seems as though this floor has some sort of divider running through
>> it.
>>
>> The main control valve (that apparently controls the overall flow of hot
> air
>> to the cabin through this duct) is in the engine compartment. I have
> taken
>> off the main hose that comes from the heat exchanger and felt inside this
>> control box. It feels as though there is a large flap-type valve, and it
>> appears to be fully closed (at least that is what it feels like.) I am
> not
>> sure if this valve is also split? I cannot feel far enough inside the
> unit
>> to be sure.
>
> The control valve on the firewall feeds a distribution box that should
> send
> the warm air to both cabin heat ducts equally, the cabin ducts have a
> divider to divert some heat to the rear seats. The seal on the flapper
> valve
> may be deteriorated and allowing heat to pass through in the closed
> position
> but that doesn't explain why there is hot air on one side only.
>
> If the panel heat control is fully open does warm air flow from the
> passenger side?
>
>

[Jay Honeck]

> Regarding the rear seat area, I don't think there are any vents back
there?

Yes, there are. They are on the side of the center "transmission hump" that
goes down the middle of the cabin, and are two vertical openings located
just behind the plastic flap handle housing.

If you can't see them, it's because some doofus probably carpeted over them
at your last interior re-do. I, too, had no idea that there were heat ducts
in the back seat, and my poor kids froze their butts off that first winter
we had our old Warrior. It was only after seeing heat ducts in another
Warrior that I started probing around with an ice-pick, found the openings,
and cut the carpet openings out with a razor.

Not surprisingly, this made a huge difference in the comfort of our airplane
in the winter! The small levers on the floor up front actually control
the front-to-back heat distribution on each side, so once you've cut the
carpet openings, make sure the levers are in the fully aft position.

Good luck.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"