Janitrol heater
 

Two questions:
1) Has anyone taken advantage of the C&D special show pricing and put in their heater replacement. If so, what was the cost of the heater, and what was the cost of the labor to swap it out. pirep on it?
2) IO've looked throughout my POH and can not seem to find the fuel flow requirement for the Janitrol heater on my T337C. I understand my new JPI fuel flow gauiges will not reflect the fuel used by the heater and I want to makie sure I'm calculating actual burn with the heater turned on...anyone have the fuel flow numbers?

-Robert Morris
rmorris@agsi.us
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FORD VERVE CONCEPTS

'Nother heater question:

We're not too impressed with the idea of starting a fire in the nose of our T337C for heat - a muff-type heater, or an electric heater, sounds much better. We've been unable to find a drop-in electric heater replacement for the combustion heater, or a muff-type heater to put around an exhaust stack - has anybody heard of any of these options for a T337C? Or is the C&D replacement combustion heater truly the only realistic alternative?

How many incidents have been caused by the combustion heater? I have not ever heard that using these is a danger. I agree that having one of these units on fire producing heat while flying across the country could look and seem like a hazard. But these are proven appliances and with proper maintenance and use will be fine. There are a large amount of GA aircraft that have these units and you just don't hear about planes falling out of the sky. I did a quick search on the FAA site and only found 2 incidents and one of them didn't say anything about the heater. If there are more incidents that I am not finding here please pass them on to this thread.

http://www.ntsb.gov/ntsb/brief.asp?e...22X02072&key=1

Yeah, you're right - there probably aren't that many crashes caused by combustion heater malfunctions. Maybe it's the psychological aversion to the scenario - drifting peacefully off to sleep under the influence of carbon monoxide somehow doesn't seem as bad.

Of course, electric heaters risk electrical fire, and muff heaters risk carbon monoxide poisoning (although a good digital read-out carbon monoxide meter with alarm would mitigate that risk). I wonder how these three heater options compare in terms of crashes per 100,000 hours flown? Maybe combustion heaters are actually safer than muff-type heaters?

why the combustion htr on a push-pull?
 

Sorry, but I just don't understand the thinking by Cessna engineers, nor why no one has made a modification through field approval or STC to remedy it.

The reason a combustion heater is necessary on most twins is simple - the engines are out hanging under the wings, so very inefficient to try and pipe that excess heat through an exhanger into the cabin. Our engines are not out under the wings- we have one right in front of us - just a like a single engine design.

On single engine airplances it is a simple process to set-up a heat exchanger type system, no extra fuel or flame needed, to get heat into the cabin. You still have to have proper carbon monoxide detectors and sound exhaust system checks done under any system. Why not just heat the Skymaster the way a single engine plane does it?

Has anyone ever tried to use a mod that gets nice engine heat into the cabin and eliminates the combustion heater?
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Washington Dispensaries

The normal aspirated Skymaster has the heat exchanger feature. Only the Turbo and the P models use the combustion heater.

Robert,
the combustion heater uses 2.25lbs/hr on fuel, and draws it from the same tank as the front engine (left). As to the C&D heater, I swapped my old one out at the last annual. The new one actually works, the old one didn't. Be sure whoever does this for you actually reads the installation procedures and follows the checklist and checks that everything is set up properly, and then tests it at altitude. It seems that if the fuel pump for the heater is not up to spec, the heater won't light at altitude. Don't ask how I know! The folks who did this for me hadn't done this before, and didn't do it very well or very efficiently. The total cost was $6800. I won't be going back to this shop. The heater works well though, once it was set up properly.

I believe that this should read 2.25 GAL/hr. A similiar heater in other types of aircraft (Cessa 310's, 402's, Piper Seneca, Aztec, Navajo, etc) typically burn just over 2 gallons per hour.

This is the service bulletin that describes the changes to the basic installed heaters:
http://www.kellyaerospace.com/servic...-101_Rev_D.pdf

Just quoting the POH on the 2.25lbs/hr. FWIW, the C&D Associates heater I replaced the Janitrol with burns 1.5gph, max according to its Operating handbook. The heaters in 337's are 25K BTU, the larger planes might have bigger heaters, and higher fuel burn rates.

That's what I'm saying, it was a typo from Cessna, and it never was corrected. God forbid that Cessna would put out wrong information.
Think about it, 1/3 gph? That is so absurd that this is why a red flag popped up.

Skymaster, Seneca, Seminole, Baron are all comparable sized cabins as far as cubic foot areas, so they all have the same size/family of heaters.

turbo -v- aspirated
 

I'm ?? guessing ?? it has to do with trying to heat exchange at flight levels, but what about lower? Seems that the turbo should be able to be set-up with a heat exhanger and then switch over to combustion if for some reason you get high and exchanger doesn't function.

Anyone out there ever tried to set up a turbo or p with heat exchanger type heat in lieu or in addition to the combustion model?
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Puma

never tried this, but the P210 uses heat off the exhaust thru a heat exchanger. Worked fine down to -30 or so in my experience. Simple and lightweight. I wonder why Cessna didn't change to this on the later models?? The C&D heater works well though.

The T337H has a heat exchanger and only uses the heat from 2 cylinders. I guess it works good because the pilots don't whine about being cold.
Kim

I replaced the heater in my T337B two years ago with an O/H'd one from Janitrol ("Kelly Aerospace" now) and it was just under $2K through Harold Haskins (Dothan, AL). It was a totally new core and parts so while it was an "overhauled" heater it really is new now. I pulled the old one out and put the new one in and then my A&P's finished up one dififcult part of the process that was giving me some trouble and signed it off (less than $200). I spent half a day getting it out and half a day getting the new one back in. For certain steps of the in and out process it was really a 2-man job, and I had a good friend help for a couple of hours.

I can't get too excited over that endlessly quoted line "why light a fire" in the airplane for heating stuff. The heater works fine, it does the job, and if the other type had worked well at the time they designed the T's and P's I suspect they'd have used that instead. My A/C is certificated to 33K feet, and it needs a good heater when you get high and cold.

heat exchange
 

Kim,
You suppose there is a way to convert to the 337H set-up and eliminate the Janitrol heater?
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NASH 600 SPECIFICATIONS

The cost of a T337H Fwd exhaust system is 4K-5K then you have the ducting and control valves It will be much more cost effective to buy a new heater or two. The biggest problem with a Janitrol heater was getting a cracked combustion chamber and everyone expiring from CO posioning. But a heater/muffler type system will do the same thing.
Kim

C&D heater remains tepid
 

I had a C&D put in abut a year ago, and it's outlet air temp remains tepid.

New pump, pressure regulator, etc from C&D

Did you have to do anything special to it?

Did yours eventually put out heat like the old janitrol?

D

David,
the best suggestion I can make is to call C&D, make an appointment, and fly up and see them in person. They can check the whole thing and get it set up properly. I have heard they are very good at this when you show up on their doorstep and folks leave happy campers. I have no idea as to cost though. FWIW, once my C&D heater was properly set up, it worked just fine. The problem in my case was that the fuel pump didn't put out enough pressure so the heater would light properly. That pump does have a screen that needs cleaning on occasion too.

Janitrol heater
 

Can the Janitrol heater be removed on a P model? We operate 100% of the time in the Caribbean, Mexico and Ceentral America. Never have a problem being too cold.

I would like to permanently remove the Janitrol and get rid of some of the space consuming plumbing. However, we want to do it correctly and legally. Are there any options?

Janitrol overhaul or other options
 

OK, my Janitrol heater has now failed the decay test and is removed by the a&p doing other work on my front engine. Curious on options others have done. I need heat (turbo I usually fly high, and it has been very cold recently without a heater at 21K in November :).

Looking for cost effective options, because I am already having to handle an engine overhaul right now in the pocketbook.

Again, looking for all options and comments please. either her, or email me at rmorris@agsi.us

Thanks,
Robert

Not many options out there Robert, find an overhauled Janitrol or go for the C&D non AD unit

heat exchanger
 

Trading voicemails with mechanic sounds like he might be able to make a heat exchange option similar to what is in his normally aspirate skymaster and remove the janitrol heater, which was an option from factory, by doing a 337 form.

Other than the obvious. make sure my CO2 detectors in the cabin are working before each flight. Any other thoughts on the subject?

What about its ability to heat at high altitudes, versus the Janirol? Anyone have the heat exchange (non-Janitrol style) heater and fly in the upper teens or even low 20s?

Robert

Check out this thread, http://www.337skymaster.com/messages...light=janitrol

There is an attachment that details the exhaust for the T model. It indicates a muff over the muffler but only one and I don't see any scat tube connections.

You could try to duplicate a normal aspirated system on your T model but it will require a field approval for the STC as I don't think there is an STC out there. I could be wrong so you might want to give Don Neiser a call or Owen Bell as they may know.

Good luck