PA28 Heater Controls: What are these things?

wkbowserwkbowser
in General Discussion
;I have a PA28 Archer that has a lever with a knob on the end located on the metal down by your feet each side of the tunnel that goes from the front to the rear. The POH and the parts book say they are heater controls. Mine will pull to the rear and I can feel a spring pulling them back forward. They don't seem to do anything. The heater airflow doesn't change. I don't feel anything being moved. I do know that the metal around the knob get so hot it wll burn you. It would seem that the metal is suppose to duct air to the rear but I don't feel any hot air going to the rear as my rear seat passengers will tell me.

What are these levers suppose to do?

Thanks,
Bill

Comments

  • flyguydonflyguydon
    They open and close the vents down there. They will do nothing much unless you turn on the heat using the controls on the panel in front of the co-pilot towards the right side. One says defroster and one says heat.
  • flyguydonflyguydon
    Where are you based? I am doing an annual on an Archer this weekend. I am near Jacksonville, FL if you are ever by this way!
  • wkbowserwkbowser
    I'm in Atlanta but don't plan to go to Jax anytime soon.

    I have turned on the heater controls by the copilot seat but nothing happens when I pull these levers. I suspect they are supposed to control some damper to redirect air but they don't seem to do anything. When I pull them I feel the spring pressure and when I let the lever go the spring pulls it back forwared but I don't hear anything moving. There doesn't seem to be a locking position for the lever either. Maybe in the past something was disconnected before I purchased it. I just don't know what it is supposed to control.

    If I can figure out what it should control then I can find the disconnect.

    Thanks,
    Bill
  • flyguydonflyguydon
    Well, the heater main controls control airflow from out under the cowl from the shroud that is around the mufflers. One to the defrosters and one to the ducts on the floor between the pilot and co-pilot floor... where you are talking about the other controls...
  • wkbowserwkbowser
    maintenance manual page

    The knob/lever that I am talking about is item 2 on the attached page from the Piper parts manual. I can pull it to the rear of the plane when the heater is on but no air flow seems to change. A spring pulls it forward when I let go. I don't see anyway to lock it aft. Basically it doesn't do anything.

    Thanks,
    Bill
  • AirikAirik
    On my Archer, the knob you are taking about controls the heat duct. I don't think there is suppose to be a spring on them. It's possible someone hooked up a spinto keep them either open or closed but I can't imagine why. Mine definitely has heat coming from them if they are opened. I fly another Archer occasionally and they work the same way as mine do. There is no spring shown in the parts manual either. Something may be blocking the duct behind the panel.

    Eric
  • flyguydonflyguydon
    If someone put a spring on it, I am certain that they were trying to keep it closed during the Summer or something... I f the main control works properly, that should not be a problem as it should not allow heated air to those vents.
  • TMyersTMyers
    When you pull the small lever near the floor aft it blocks airflow to the pilot or co-pilots feet and sends it back to the rear seat passengers. Mine does not have a spring either nor should it.

    The heat lever control a damper that is mounted to the firewall. This damper takes the ram air that is passing through your heat exchanger and either diverts it outside the airplane or channels it into the airplane. There is a damper assembly on each side of the firewall for the two heat ducts at the floor. They are individually adjustable for the amount of open or divert you want.I have the copilot side (wife's) set to open first and more because she is usually freezing where mine opens later. The heat exchanger puts out some really hot air so be careful with it.

    I forget exactly how the defrost damper works I just know the tubing is much smaller and there are two of them.

    If you are not getting heat your damper could be jammed or the cable may not be functioning correctly. It is also possible that the hose or hoses might be disconnected.

    Good Luck and have fun.
  • wkbowserwkbowser
    There are some very good suggestions here. After reading them I think that a past owner has put a spring on them to hold them forward. Even if I hold them aft I don't feel any change of air flow at my feet.

    I will take the ductwork apart and see whats going on with them. I have plenty of heat from behind the dash so that part is working and the metal around the levers is very hot. The damper or blade or what ever closes off the heat at your feet must be disconnected.

    Thanks all!
  • n36601n36601
    Bill:
    TMeyers has pretty well stated the answer. There should be no springs on those levers, and you should feel a GREAT amount of heat on the top of the aluminum channels. A properly functioning heating system on a -181 or even the Hershey Bar Archer will cook you right out of the plane, even in the coldest weather. Here's a page from the -181 manual illustrating the heating system. The key to a properly functioning system is the heat diverter box at the center bottom of the firewall. Make sure the cable from the HEAT lever is moving the flapper assembly to the fully closed position, when in the OFF position. Then make sure the flapper opens smoothly to allow heat from the muffler shroud to pass through to the center duct. Also, check the flapper for a good seal to the box, that is no warping.

    The small black levers on the center channel move forward to divert heat to the front seat, and rearward to divert heat to the rear. I usually leave mine in the REAR position all the time. You'll melt your sneakers if you use the FRONT position.

    mini_14012012-2200_Archer--181-heater.jpg

    Keep us posted on your results.

    VFRs, without TFRs,
    Dennis-ARR
  • TMyersTMyers
    Didn't realize the Archer had a single damper assembly. My Arrow has two and mine are adjusted slightly differently to provide more heat quicker to the Co-pilot (Wife's) side than to my side.

    One thing to caution you about. The aluminum is very thin and you need to be careful about trying to turn any screws or nuts as the levers and arms will bend very quickly.
  • wkbowserwkbowser
    Well the mystery is solved. I took the aluminum pieces that have the heat outlets by your feet and found that the last owner or at least one of the owners had installed new carpet in the heat duct channel that runs from the front of the cabin to the rear seats. When the metal pieces were reinstalled there was not enough clearance to allow the little damper door to move so when I tried to move it the wire that connects the knob to the damper door just sprung like a spring but the door never moved.

    Then in the rear where the air should have came out was blocked by excess carpet that kept air from flowing out. I cut out all the carpet that was affecting the system and got the damper doors working and the trimmed out the excess in the rear. I have not flown it yet but I am sure that it is fixed.

    It was not a lot of work but there are a lot of screws to remove so if you go into this make sure that you have an electric screw driver.

    By the way, It was a great time to try a unique fix for the chipped up flap handle. Someone on this forum suggested that a 1" piece of heat shrink makes a good fix for it. I finally found the 1" heart shrink, took the rubber handle off and put a cut to length size piece on and heated it. Worked great. It’s a little dull but looks better that the old chipped up handle.
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