Just prior to last winter I installed a Tanis heating system. My general practice has been to leave the system on during periods of below 30 degree weather, which could be weeks at a time.

Along with the Tanis, I have a small ceramic heater in the luggage area to keep the interior above freezing. This really helps the instruments and, since the battery is under the front passenger seat, it is much easier on it to.

This approach seems to be working great because each time I get in the airplane, I can hear little voices from the engine, instruments and battery thanking me!

Anyway, a fellow mentioned to me that leaving the Tanis heater on for extended periods was probably not a good practice because the changes in temperature would cause a moisture build up in the engine. I should only turn it on before using the plane. The Tanis instructions and web site do not say anything either way. It seems like keeping the engine warm would keep the moisture out of the engine.

So having nothing to do at the moment I thought I would ask you guys about this. Thoughts?

i have been using tannis heaters here in sub zero mn for 20 plus years, i only plug them in for 12 hrs max before flight, got this from the folks that build them here in glenwood mn.

Don't leave the engine heater on for the reason you mention. You can buy a coffe maker timer at Wallyworld that will handle 1800 watts for very little money, or you could get fancy and get a pool timer that also has the days of the week.

I don't buy into the condensation theory, When I have mine plugged in the complete engine compartment is warm.

For condensation to form you have to have two temperatures. If you cover it when its warm and plug it in how can any even form.

When I shut down I open the dipstick install the engine cover and plug it in if I am flying in the next couple days.

I think some smarter people than I, have already disproved this wives tale.

I have the occasion to work with some major engine manufactures who also feel if the entire engine is warm it doesn't form.

I don't leave mine plugged in all the time but see no reason to worry about doing so.

Now if your not covered, and the cold is against the crankcase then you can get condensation.
And you also can expect some if plugging in a cold engine but once the temperature stabilizes you shouldn't be able to build any more.

The problems arise when you fly and you don't get 180 or better temps to cook off the moisture.
Then you go back and plug them in.

Good reason to change oil more often in the winter.

Yes, think about what a64 suggested--putting the engine heater on a timer. Now, when the heater kicks in, the engine warms up. Fine, but at whatever time you have it set to turn off, the engine cools, and draws moist air(or at least moister air) into the engine itself. Now, the heater turns on again, and you repeat the cycle, constantly heating and cooling the engine inside out. That to me is a recipe for corrosion, and I'd rather either ONLY Turn it on when I'm actually going flying (which requires a trip to airport , or just leave it plugged in.

With it plugged in all the time, and with a GOOD engine cover (and Tanis' engine blankets suck, frankly) the engine will stay at a relatively constant temp range. All the while, the heat should be driving moisture OUT of the engine.

Of course, I'm assuming you're not going to actually go fly every day--if you are planning that, maybe the timer is an idea.

Obviously the best way to prevent corrosion is to fly frequently, and in winter that's hard to do.

MTV

Come on Mike, just get one of those pager switches.

Heat is only a phone call away.

I have the analog type, I call my wife and tell her to go plug the plane in

The idea was not to let the heater cycle, but to not have to show up hours before you were to fly.
I don't know the reason, but engine heaters will cause condensation inside of the engine. For some reason I haven't seen the cheapest of heaters cause a problem, the drop light. Maybe there isn't enough heat?
Pre-heating isn't a problem this far south, so I do not have the experience you guy's have. I have seen internal corrosion presumably from engine heaters left on though. Maybe the engine compartment wasn't insulated enough? or maybe these were in much more humid environments than Nevada?

a64pilot wrote: For some reason I haven't seen the cheapest of heaters cause a problem, the drop light. Maybe there isn't enough heat?
?

It works because its heating the crankcase first.

The warm vapor hitting the top of a cold crank case and instant condensation. So if you cover it then plug it in while warm you can leave it plugged in.

I think a bunch of folks don't have a quality cover and that could be a recipe for trouble.

mr scout wrote:I think a bunch of folks don't have a quality cover and that could be a recipe for trouble.

That engine blanket has to be good quality and cover all openings to the cowl. Plus, it's your emergency sleeping bag/shelter if you have to park it in the sticks overnight!!! Me, I like to stay warm too.

Gump

I leave my heater on as well, but note the earlier comment regarding pulling the dipstick open, which allows another route for moisture to escape. As mentioned, would not recommend this if you can't get the whole engine heated relatively uniformly, for whatever reason. I have been duct taping the oil cooler in the Citabria to ensure good engine temps in cold weather, but wonder if anyone has info for me on where to get or how to make a winterization kit for the 180?
Matt

I have an E-Z heat engine heater which is nice because it has a thermostat built in, so just plug it in and it cycles on and off to maintain the temp. Not very expensive and it works great.

Merry Christmas to flying friends
Maybe 10 years,Tannis changed its opinion on leaving the system on all the time. Moisture problems in the back case generator drive area of big block Conti's was an issue associated only with this procedure. Also some think Cyl heaters thin the oil to the point where it weeps off the Cyls. The small amount of residual oil remaining at shut down in the Cyls is needed for startup.

Just my 2 cents on heaters, Although I had Tannis in my last 2 planes, I used it only for pre heat before flight. I don't care for the Tannis for more than 4 hours. I think it has hot spots next to the eliments where you have little oll remaining. If you have 4+ hours,I also like the oil pan heater patch with the blanket. In remote places way below zero, I have used the quick drain to drop the oil into a pan to be warmed on the wood stove.This saves moving parts on startup, but I think the rapid temp change of adding hot oil to a cold motor has a condensation effect adding moisture.

I have used the reiff preheaters on two aircraft and they work well. Unlike the tanis, they heat from the base of the cylinders outward thru the cylinders and into the case as well as heating the oil pan. Kennon aircraft covers with the prop blades and spinner covers expedite the process as well as keeping the engine warm for several hours if you make a stop. I have used this system down to about -15f with excellent results.

winger wrote: In remote places way below zero, I have used the quick drain to drop the oil into a pan to be warmed on the wood stove.This saves moving parts on startup, but I think the rapid temp change of adding hot oil to a cold motor has a condensation effect adding moisture.

Condensation is not an issue though, as you're firing up the engine such a short period of time afterwards. Any water formed is going to be consumed when the engine is running. And, like you say, in remote places below zero it's not like you have lots of other options.

Me, I'll combine heating procedures depending on where I'm stuck or camped out. I like dumping the oil at the end of the day just because it's easy and I have complete control of how warm I heat it next morning, but I'll also stick a gasoline/propane heater under the blanket to get the case and crank as warm as I can too.

The battery is another issue. If stuck out in the cold with no electricity, I'll pull the battery and keep it warm for the night too. Hard to start a warm engine with a frozen battery.

Gump

I have the reiff heating system as well. Absolutely no complaints so far used it down to 10° and after an hour or so the plane is around 60°.

As far as the condensation goes. I believe I read in aviation consumer that if your plane is left plugged in continually. The moisture in your plane engine will remain at the same level as when you parked or in some cases decrease, like a few people have stated here before me the trouble comes when you heat, and don't fly and unplug and then heat again
pretty much common sense anything cold draws moisture just think of your Pepsi can in the summertime summertime

I have the reiff heating system as well. Absolutely no complaints so far used it down to 10° and after an hour or so the plane is around 60°.

As far as the condensation goes. I believe I read in aviation consumer that if your plane is left plugged in continually. The moisture in your plane engine will remain at the same level as when you parked or in some cases decrease, like a few people have stated here before me the trouble comes when you heat, and don't fly and unplug and then heat again
pretty much common sense anything cold draws moisture just think of your Pepsi can in the summertime summertime

Do any of you guy's dillute yoir oil when it's real cold?

a64pilot wrote:Do any of you guy's dillute yoir oil when it's real cold?

I used/use Aeroshell multi-grade year round up north and down here with good results. Never saw a need to dilute anything as I always preheat.

Gump

I flew a Beaver for a number of years that still had the dilute switch in it, as well as one 185.

I was somewhat rudely informed by our Maintenance Chief when I first started flying the Beaver that if he ever found out that I'd used dilute instead of properly pre-heating HIS engine, he'd see to it that I was driving boats the rest of my career.

Never did have a hankering to dilute after that.

MTV

mtv wrote:I was somewhat rudely informed by our Maintenance Chief when I first started flying the Beaver that if he ever found out that I'd used dilute instead of properly pre-heating HIS engine, he'd see to it that I was driving boats the rest of my career.

Never did have a hankering to dilute after that.

MTV

I think that guy's twin brother yelled the same speech to me too..... And I didn't.

Gump