Janitrol heater not working

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Tokirbymd

Pre-takeoff checklist
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Tokirbymd
New plane- Janitrol i3500 heater not working (PA34-220T). Blower fan works. Combustion overheat light didn't come on. Looks like there is a broken wire on a resistor in the duct switch assembly. Would this cause the problem? Or am I wasting time chasing this problem and need to consider bigger items?
 
There was a DC-3 named “The Killer” as it was previously owned by Jerry Lee Lewis.

On board was the musician Rick Nelson and his band.

There were problems with the heater that were not addressed.

“Music’s Broken Wings “ will give you the NTSB and autopsy results.

Rumor says the Cap told the FO ( only survivors) to shut up about the problems.
 
Doc Holliday said:
I've operated them in numerous aircraft, and rarely a problem. The key was they were properly maintained.

Non maintained units are a constant problem.
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Of course, it’s also possible to operate them in a manner that makes them unreliable.
 
They work better with gas than Jet fuel. Still.........mostly a piece of junk.

King Air 65-A90

Ours had impeccable maintenance, open checkbook, from a large Beech dealership, Flightcraft in Portland, Seattle, Spokane and Eugene.

Fortunately, it had "Supercharger" heat............that when in use made it smell hot.
 
kgruber said:
They work better with gas than Jet fuel. Still.........mostly a piece of junk.

King Air 65-A90

Ours had impeccable maintenance, open checkbook, from a large Beech dealership, Flightcraft in Portland, Seattle, Spokane and Eugene.

Fortunately, it had "Supercharger" heat............that when in use made it smell hot.
Click to expand...
Once we figured out that the nozzle needed to be kept clean, it worked great in our B90.
 
Tokirbymd said:
New plane- Janitrol i3500 heater not working (PA34-220T). Blower fan works. Combustion overheat light didn't come on. Looks like there is a broken wire on a resistor in the duct switch assembly. Would this cause the problem? Or am I wasting time chasing this problem and need to consider bigger items?
Click to expand...
Yes it will. note that the capacitor is a "Z" rated affair (for heat) so not just any matching capacitor will do. I experienced this! WIthout one, the contacts which fires the thing, arcs out.

I subsequently replaced the whole unit with a C-D Associates solid state + ceramic heater (PA34-200T). Over the years, MUCH more reliable!
 
bbchien said:
Yes it will. note that the capacitor is a "Z" rated affair (for heat) so not just any matching capacitor will do. I experienced this! WIthout one, the contacts which fires the thing, arcs out.

I subsequently replaced the whole unit with a C-D Associates solid state + ceramic heater (PA34-200T). Over the years, MUCH more reliable!
Click to expand...
Thanks! Thats what I was thinking as well. On what parts and maintenance manuals I could find- there didn't appear to be a capacitor in that position and it looks to be a very fragile location for a disc capcacitor so wasn't sure if this was some wonky attempt at repair in years past. The same capacitor (Z rated etc) on mouser is only $5. I'll ask my guy if he wants to replace that vs pulling and replacing the whole duct switch assembly. I'll take a look at the solid state heater also.

On a technical note- is the capacitor there to take up surges in the switch operating on/off during temp changes?
 
On some airframe, I forget which.......There was a mod that ducted hi-temp air from the engines (like a single) into the airframe and did away with the POS Janitrol.
I think it was for a Seneca I
Or maybe an Aztec.
 
Tokirby: the temp control controls both the fuel flow and the igniter rate. It’s repetitive ignition (to prevent it from becoming a bomb). So the repetitive ignition arcs out across what are essentially Kettering “points”; no continuous ignition and the fuel cutoff shuts it down.

If you replace the capacitor (Z-rated only) pay meticulous attention to how the leads are secured. After tolerating that thing for about 5 years before I said “Enough”. A squish out door seal and doubled BTUs was worth it.

If you’ve looked at where it mounts it’s on the bimetallic strip unit…a high vibration location. NO BUENO.

 
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bbchien said:
Tokirby: the temp control controls both the fuel flow and the igniter rate. It’s repetitive ignition (to prevent it from becoming a bomb). So the repetitive ignition arcs out across what are essentially Kettering “points”; no continuous ignition and the fuel cutoff shuts it down.

If you replace the capacitor (Z-rated only) pay meticulous attention to how the leads are secured. After tolerating that thing for about 5 years before I said “Enough”. A squish out door seal and doubled BTUs was worth it.

If you’ve looked at where it mounts it’s on the bimetallic strip unit…a high vibration location. NO BUENO.
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That makes sense. Replacement switch assemblies are in the 1 AMU range. Do you know if you can replace with a solid state switch as opposed to a full heater replacement?

but agree, that’s a terrible design.
 
bbchien said:
Tokirby: the temp control controls both the fuel flow and the igniter rate. It’s repetitive ignition (to prevent it from becoming a bomb). So the repetitive ignition arcs out across what are essentially Kettering “points”; no continuous ignition and the fuel cutoff shuts it down.

If you replace the capacitor (Z-rated only) pay meticulous attention to how the leads are secured. After tolerating that thing for about 5 years before I said “Enough”. A squish out door seal and doubled BTUs was worth it.

If you’ve looked at where it mounts it’s on the bimetallic strip unit…a high vibration location. NO BUENO.
Click to expand...
What heater did you replace it with? Hartzell bought both Janitrol and C&D. Looks like there is an iconel replacement with solid state switches for $12k
 
bbchien said:
C&D.
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Since Hartzell bought both Janitrol and C&D, they are selling an I model now. Is this derived from the Janitrol design or the C&D? Looks like it has solid state switches at least
 
I sent my old Janitrol (in a
1975 Be 55) that was problematic to Harold Haskins Inc in Dothan, Al. He does a conversion to an Inconel (I-5000) that eliminate all ADs', cost about$4k, and so far works fantastic. Haskins's offers great support (I called numerous times during the re-install). Great way to get reliable heat at less than half the price (and much quicker) than new. Turn around time was less than two weeks.
 
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