I purchased a 1982 Cessna Crusader this summer and have been getting to know her over the past few months. Now that the wintry weather has arrived, I am using the heater a lot. It was just pressure tested at its last annual in July, and the spark plug is in tight. On an evening flight this past weekend I noticed a rather anemic heat output along with a substantial flow of cold air onto my feet from an open area in the center console. Asked my mechanic to take a look at the heater and ducts to make sure everything looked OK. He fired up the heater in the hangar and got a lot of smoke in the cockpit, setting off the CO alarm. When he tried it again on the ramp with the engines running there was no smoke in the cabin. The exhaust for the heater is right under the nose, so is this normal behavior? I've never tried running the heater in the hangar before. Any thoughts?

Dan

Does yours have a ground blower fan?

Yes, there is a blower fan. (I presume you are describing the fan that turns on when the heater switch is in "vent fan" or "heater" position:

There are separate fans for the internal air and for the combustion air. There should also be a flow vane that shuts off the fuel if the combustion air is not flowing. The combustion fan should come on automatically with the heater itself. The vent fan runs with that switch but may have a weight on wheels sensor that forces it on while you're on the ground.

Dan, I don't know about your Cessna, but the Baron experience you got with smoke in the cabin at rest is what I would expect from the Janitrol in my Baron. These heaters seem to run rich as hell on the ground. They produce a lot of black smoke at rest. I have used them to preheat the cabin, which is a mistake.

Anyhow, one of the coldest flights I've every had was going in to Tulsa in February with an in-op heater. You don't ever want that. Heaters aren't particularly complicated, but there are proscribed maitenance techniques to keep them running well. Mike Caban's site has an excellent page on this: https://www.csobeech.com/Baron-Heater.html

In my case a new spark plug for the heater has kept it running well for many years.

good luck!

--paul

the Janitrol on my Aztec burns quite rich and will belch out black smoke sitting on the ground.

I also had the heater once fill the cabin with smoke, the intake for the heater on the Aztec is just in front of the nose wheel doors and I had birds make a nest in the inlet and I thought I had gotten it all cleaned out, apparently not I turned on the heat while on the ground and very quickly the remaining straw that was missed was drawn into the heater leaving a lot of smoke behind.

I even through quickly realized what was happening I was really glad I was still on the ground at the time.

Oh I now have a plug for the heater inlet, no more birds

So I recently completed about 10 hours of cold weather cross country flying in my 1980 BE58. The heater seemed to work fine for me up front for most of the flying but for my passengers, it was pretty brutal at times. No matter how much I attempted to provide more warm air in the back - by setting max cabin heat and closing the defrost and both of the pilot and copilot outlets - the heated airflow for the back behind and under the copilot seat and under passenger seat 4 was anemic. Time to time it would just seem to shut off (the 180 degree switch i assume) earning me some criticism from back.

A G58 training manual I have referenced for insight states “to obtain maximum heat, position vent air control slightly more than 50% open” but finding that sweet spot is an art that has been elusive to me and whenever I jigger with the cabin vent air slider to get a little better performance from the heater, I end up pulling to below the 50% threshold causing a shut down to prevent overheating. My slider is pretty hard to move, and does not seem to slide the full travel of the notch provided. My “technique” has been to slide it as far forward as I can and then back it off about a finger width. Whenever I check it in flight, it seems to have found the forward stop again so I repeat the process of backing it just a bit.

Does anyone have some good info, video, or reference material on getting the most out of your janitrol heater?

Reach out to Paul Miller at Aircraft Heating in Redding California, he seem to know everything this is to know about the Janitrol and South Wind heaters.

Helped me diagnose a problem on a Sunday night initially via Facebook chat then a phone call, had parts out the next morning to me.

There's a good chance your heater is working fine but you can check that by measuring the temperature of the air coming out of the right front footwell outlet. It should be at least 160°F with the temp control pulled out all the way.

There are two things that cause a cold aft cabin when the heater is doing all it can. One is air leaking into the cabin, either through the overhead vent system or door/window seals. The other is a collapsed duct running from the right front, under the floor to the outlets behind each spar.

On an ‘80 Baron, I’d put money on the ducts under the floor, between the fwd bulkhead and the aft side of the spar cover, having some combination of broken, crushed and disconnected. If you are comfortable up front, the heater is likely fine. Also, check the main gear push rod boots. A lot of cold air can get into the cabin under the spar cover if the boots are not in good shape.
To determine how far the iris valve control can be closed without shutting down the heater, turn the battery on, place the heater switch to the fan postion. Now move the iris control toward close. When fan shuts off, note the position of the control. Don’t move it that far aft in flight unless you want the heater to shut off.