Loren, the Janitrol (and Southwind and C and D Heaters) are all owned by Hartzell Engines, and I recommend that you go to the website and find the Janitrol Heater section.

There are a few options, and before you spend a lot of money chasing a gremlin, Hartzell Engines sells an overhaul kit which includes an Inconel lined combustion chamber and by installing this you no longer have to comply with the 2 year pressure decay test requirement.

The second option is to placard the heater as inoperative, pull the breaker and not use it.

The third is to have it overhauled. There is a well regarded overhauler named Harold Haskins, and while Harold has passed away, his son runs the business and he goes overboard with help. Look them up and see if you are in his area. 

Since the plane was in Texas the chances are that the heater wasn't used. Look in the logs and see if there is a record of the prior owner having had the biannual pressure decay test performed.

The reason for the pressure decay test is to verify that there is no leakage that can allow CO to enter the cabin. There is sulphur in fuel that is generally removed at the refinery, but a little remains. When hydrated it becomes sulphuric acid which etches the combustion chamber.

When you research the ADs you'll see reference to ceramic coated combustion chambers, and Kell Aerospace Heaters, and this can be confusing. Jeff Kelly owned the Janitrol STC for a time, so that's why you will see that name, and the ceramic coated combustion chamber was designed to provide a resistant surface so that etching would not occur but the ceramic cracked, and acid got in between the cracks and etched the metal, so the same AD was applied to the ceramic lined heaters as the regular ones. 

There are a number of issues that can cause the heater to not function, and others that cause the reset button to pop open. The fuel nozzle (atomizer) can get carboned up. The igniter (big spark plug) can get carboned up and weak. The motor is like any electrical motor, and has brushes that wear, and can require overhaul. I guess the point is that the heaters are a specialist's domain and you should not let just any mechanic loose on them. 

I'm familiar with these heaters --- if you want more information I'm happy to help. They are good heaters, but they have to be maintained. Yours sounds like it may not have been.

Pat

The classic law of mechanical inertia states that if a machine is not working then it it will continue to not work when called upon.  I would like to follow up with Pat's suggestion of having a specialist have a look at it.  Perhaps it can be removed and mailed off for a cleaning and rebuild?

@patricbarry thanks for the detailed and informative post. Looks like we have some research to do to understand where ours stands.  I'll keep this thread posted on what we find.  Thanks, again.

Loren

Your issue should be easy to resolve since you already have used the heater. As you will learn, there is an overheat sensor which can cause that little red button to pop. It could be worn brushes, Could be a few things. 
I'll wait for your news.

Pat

@patricbarry agreed. I understand there are two fans. I know one is working, as we can hear it running on the ground.  We need to figure out if the other one is working. We'll be digging into it shortly.

Hartzell Engines has the STC for Janitrol, and they have technical support people. Look at the Hartzell Engines website. I'd like you to have a Janitrol service manual before you start opening it up.

Pat Barry

A very long time ago I decided to have my Janitrol overhauled / serviced, so I took it to Mailboxes USA (now United Parcel) and had them pack and ship the heater. I had it shipped to the Redding heater facility.

I received a phone call telling me what they would charge for the service, "But what about the damage?". Huh? What damage?

UPS played football with my package and the store inadequately packed it. That cost me $900 back when $900 bought what $1800 does now. So make a wooden box and prepare it well.