Overhaul heaters?

[Mcstealth]

Question please. 

Where does one send this kind of heater for overhaul? 

It has low hours on the Hobbs meter, less than 200, but the owner says "something " is not working and it won't turn on. 

It is out of Twin Turbo Comanche. 

[EricJ]

Janitrol heaters are extremely common and used on nearly all recip or unpressurized twins.   You probably won't have to look far for an A&P that is familiar with them.    They're very simple and it shouldn't be difficult to figure out what's wrong with it.

 

[N201MKTurbo]

There are flow switches on the combustion blower and on the fuel supply, I would start there. Then make sure the spark ignition is working.

[N201MKTurbo]

So, what doesn’t work? Does the main blower turn on? Does the heater not work? 

You need to have cabin airflow, combustion airflow and fuel pressure before the fuel solenoid will open.

It never hurts to do a pressure test too.

[Mcstealth]

1 hour ago, N201MKTurbo said:

So, what doesn’t work? Does the main blower turn on? Does the heater not work? 

You need to have cabin airflow, combustion airflow and fuel pressure before the fuel solenoid will open.

It never hurts to do a pressure test too.

I will get down to brass tacks soon. The owner asked me who overhauls them and that is the extent of my knowledge right now. I figured I could ask here on the forum and get direction. 

I think I will tackle it. How hard could it be? 

Hehe. Did I just say that?

Thanks. Get back with you soon. 

[Andy95W]

If it doesn’t “turn on”, it’s possible that the reset switch has to be pushed.  That’s the little red button to the right of your picture with a couple of wires going to it.

[Mcstealth]

1 hour ago, Andy95W said:

If it doesn’t “turn on”, it’s possible that the reset switch has to be pushed.  That’s the little red button to the right of your picture with a couple of wires going to it.

Thank you. 

[N201MKTurbo]

I’ve heard the overhaul cost for these is very high. Around $5000. There are ADs that apply. If it doesn’t require an overhaul, I would try to fix it.

[N201MKTurbo]

https://janitrol.aero
 

It is a Hartzell company.

[philiplane]

the best place to overhaul it is http://www.haroldhaskinsinc.com/

the second best place is on the label. AHE.

But the main problem is often that they don't get used often enough. Which means the fuel lines from the shut off valve to the heater, and the wick inside the heater, are dry.

So the heater may not be primed with fuel. It re-primes by turning it on FAN for a few minutes, and then to HEAT. Then it should be primed, and light off as it should.

 

 

[Mcstealth]

58 minutes ago, philiplane said:

the best place to overhaul it is http://www.haroldhaskinsinc.com/

the second best place is on the label. AHE.

But the main problem is often that they don't get used often enough. Which means the fuel lines from the shut off valve to the heater, and the wick inside the heater, are dry.

So the heater may not be primed with fuel. It re-primes by turning it on FAN for a few minutes, and then to HEAT. Then it should be primed, and light off as it should.

 

 

Can they be tested on the ground?

[Andy95W]

1 hour ago, Mcstealth said:

Can they be tested on the ground?

Yes, but depending on the aircraft installation, it may need a source of fuel pressure before it will run.  The POH should explain its use.

Edited March 18 by Andy95W

[Mcstealth]

23 hours ago, Andy95W said:

Yes, but depending on the aircraft installation, it may need a source of fuel pressure before it will run.  The POH should explain its use.

Yes. The owner did say the heater needed fuel pressure.  Thanks for the reminder. 

[EricJ]

1 hour ago, Mcstealth said:

Yes. The owner did say the heater needed fuel pressure.  Thanks for the reminder. 

Fuel pressure, spark, and airflow.    Most of them have a lockout/safety switch that doesn't let it run unless there's sufficient air going through it, either from the fan or the ram inlet.

 

[Andy95W]

@Mcstealth

Janitrol-MaintenanceManual 2.pdf

[Mcstealth]

On 3/19/2024 at 10:52 AM, Andy95W said:

@Mcstealth

Janitrol-MaintenanceManual 2.pdf 4.84 MB · 3 downloads

Let's see if this has a trouble shooting guide. 

[cliffy]

I've done those on my own bench  You can "overhaul" them but in most cases that is not necessary. IRAN is better

There is a combustion can pressure check AD that needs to be complied with every year (I had a Twinkie non-turbo). Many shops can do the pressure check in the airplane. No need to take it out. There is also an AD on the fuel shutoff solenoid to check for leaks. 

Its a very simple system to repair IF the combustor can  has no pressure leaks. 

Spark to light it off, fuel delivery (clogged nozzle) I've found this. 

Fuel pressure and air pressure to run

Getting it out of the Twinkie is a project

You might also try to remove each wire connection ONE AT A TIME and clean each with a wire tooth brush for good contact.

It looks like it has been sitting for a long time. 

[Mcstealth]

2 hours ago, cliffy said:

I've done those on my own bench  You can "overhaul" them but in most cases that is not necessary. IRAN is better

There is a combustion can pressure check AD that needs to be complied with every year (I had a Twinkie non-turbo). Many shops can do the pressure check in the airplane. No need to take it out. There is also an AD on the fuel shutoff solenoid to check for leaks. 

Its a very simple system to repair IF the combustor can  has no pressure leaks. 

Spark to light it off, fuel delivery (clogged nozzle) I've found this. 

Fuel pressure and air pressure to run

Getting it out of the Twinkie is a project

You might also try to remove each wire connection ONE AT A TIME and clean each with a wire tooth brush for good contact.

It looks like it has been sitting for a long time. 

Thank you for that. I will begin the process next week on Wednesday. Fingers crossed. 

[cliffy]

I did one on a Navajo many years ago also. They really are not THAT bad to do with the right factory  repair book. 

Pressure check it and then trouble shoot to see why it doesn't light off- It can be done.