Janitrol heater

[rmorris]

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
________
FORD VERVE CONCEPTS

[Paul462]

'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?

[hharney]

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

[Paul462]

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?

[rmorris]

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?
________
Washington Dispensaries

[hharney]

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

[JeffAxel]

Originally Posted by rmorris

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

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.

[skymstr02]

Originally Posted by JeffAxel

the combustion heater uses 2.25lbs/hr on fuel.

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

[JeffAxel]

Originally Posted by skymstr02

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.

[skymstr02]

Originally Posted by JeffAxel

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.

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.

[n86121]

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

Originally Posted by JeffAxel

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.

[JeffAxel]

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.