Janitrol Combustion Heaters

[ROB-x38]

G'day

I've recently been checked out in the PA-44-180 which has a janitrol heater compared to the usual exhaust manifold setup i'm used to.

It's been hot down here so i've had no reason to use it (if only it was reverse-cycle ;)) but was hoping somebody could give me a reasonably detailed explanation of what's happening when i flick that switch?

Cheers

Rob.

[ferrydude]

Flick the switch, the blower fan comes on, fuel valve opens, 100LL is sprayed into the combustion can, ignitor lights it off and you either get instant heat, or a nice little explosion taking the nose off. Your POH should have a more detailed explanation

[604guy]

Make sure maintenance is up to date on the pressure decay test on the heater can and ensure that there is a fresh CO indicator in the cabin.

[sanket_patel]

According to my PA-44 manual, you must take into consideration the extra fuel burn the ganitrol heater causes, 0.5 US gallons per hour. Since it also relies on ram air, it is important to turn it off immediately after landing. I'm about to fly this baby for the first time in 1 month for my multi and my IFR but since it doesn't have any de-ice... and it's the coldest month here in Canada, wont be flying in too many clouds for now. :sad:

[Kensiko]

That's kind of funny. Here in Canada on a B-99 ride, the transport inspector asked me what the burn from the heater was, and did I plan for it. Well, I did not, and I could not find the burn rate anywhere. After some calls to Janitrol itself, it was determined that, for that aircraft, the burn was insigniificant.

If you realize on taxiing in that you've forgotten to shut it down, just run the fan alone until you feel cool-cold air at the outlet. It *should* have saved the breaker in that case.

[mustafagander]

The bad news about overtemp trips on this heater is that you don't find out that the heater won't work until you're in the air. The dopey design has the reset only accessable on the ground, so you freeze for that sector.

[Big Pistons Forever]

Ernest Gann's Classic flying book " Fate is the Hunter " has a wonderfull vignet about trying to get a DC2 heater working...
Nothing much has changed :D

[pigboat]

I flew a DC-3 once with a janitrol that had a mind of it's own. One of the engineers gave me a rubber mallet and showed me where to hit the thing to reset it. ;)

[Kensiko]

mustafagander: Not necessarily true. Flick the switch as you taxi, if you see a deflection on fuel flow meter, then it is working. If not, it *may* not be.

[JABI]

Janitrol heaters, the next best thing to exhaust shrouds!
Can't anybody come up with a DECENT heating system?
Like a heat exchanger with the oil cooler?
If that springs a leak at least you don't die with a stupid grin on your face:D

[Dan Winterland]

That 'nice little expolsion' certainly gets your attention if it happens at night. Chose to freeze on that trip!

[411A]

Now on the other hand, if you are lucky enough to have a Stewart-Warner heater, many of the problems with the Janitrol design can be avoided.
S-W (and many Southwind units) cannot be run on the ground (in most aircraft) and seem more user-friendly.
At least mine hasn't caught fire yet...:ooh: :ooh:

[Zoner]

My gas heater stories:
One night flying in IMC from MID to STL at 10,000 feet in a Beech Baron there was a loud bang and sparks from behind the panel, then it slowly got very cold. Turns out a bird flew right in that little inlet hole on the nose and did in the heater. I still wonder what that bird was doing at 10,000 feet, IMC, and icing?
In seven years of Beech 18 flying the heater problems were the main CB popping ( not resettable in flight ) and the inlet icing over. It only took one cold flight to realize why all the other pilots carried insulated overalls.
JABI: One of the guys in the Cessna 195 Club was working on some type of oil heat exchanger to warm the cabin. I'll find out if he ever got it approved. In the meantime I still rely on my southwind!

[Ozgrade3]

I dont know the heater control setup on the Seminol never having flown one, but I would imagine its similar to the Duchess in having a seperate geater control know that you pull out and another knob for airflow.

Best bet is to leave the airflow control in about the mid to full open position. When switching on the heater, check for the current drain on the ammeters to indicate ignition. Most importantly, leave the heater control full in, dont touch it. Pulling it out while the heater is getting up to speed will only trip the circuit breaker. It will take a few mins to work properly and start warming the cabin. I just leave it where it is full stop, seems to do the trick.