BlueGreen World

Tuesday, January 01, 2013

Fixing the Dynaglo Pro kerosene forced air heater, Model KFA70TDGP.  
(because in a bluegreen world, you fix things instead of just throwing them away.)

Not the quasi-philosophical post you expected? Good. Too much of that will keep you useless in a user's world. Know how to repair your stuff. Take responsibility for what you own, what you need, what you use, and for your spiritual and intellectual health. As philosopher/greasemonkey Matthew Crawford observes in his book Shop Class as Soulcraft, 

"The satisfactions of manifesting oneself concretely in the world through manual competence have been known to make a man quiet and easy. They seem to relieve him of the felt need to offer chattering interpretations of himself to vindicate his worth. He can simply point: the building stands, the car now runs, the lights are on. Boasting is what a boy does, because he has no real effect in the world. But the tradesman must reckon with the infallible judgement of reality, where one's failures or shortcomings cannot be interpreted away. His well-founded pride is far from the gratuitous "self-esteem" that educators would impart to students, as though my magic."

While a seemingly natural segway into lamenting the demise of shop class in schools across the USA, among other topics, I'll let this excerpt stand alone and relate how to fix your heater, abstractions aside. 

The Dyna-glo Pro kerosene forced air heater, Model KFA70TDGP, vintage ~ 2007-2009 +, is a Home Depot offered heater that I bought because I recognized its potential to run bioDiesel, which I power my vehicles with. It accepts Kerosene (K1 or #1 fuel oil), or Diesel #1 & #2. Close enough: anything that will run Diesel or Kerosene will run at least a low blend of bioDiesel, possibly a high blend, too. For the last 5 years, I've run biodiesel blends of 20-50% through it without a single moment of maintenance. It is a great heater and has never even faltered. But last week, it finally started faltering, running for 1-2 minutes then flickering and finally stopping with a puff of very stinky smoke. Time for maintenance. Plus, it's -6F out.

Found the manual, eventually: June 23 2009.

Download this: it might not be around for long. It in itself is a good manual, and it includes models RMC-KFA125TDGP and RMC-KFA170TDGP, which I don't have and which this write-up doesn't address. 

I possess an unremarkable combination of fearlessness and naivete, which means, among other things, that I am grateful to have nearly reached forty years of age without losing digits, limbs, eyes, etc... There are scars: don't get me wrong. But I have somehow weathered most of these escapades in which I tear into something unfamiliar and fix it, which only reinforces my willingness to repeat such folly. 

Problem: ignition of the fuel. The fuel ignites but soon fizzles out and then puffs smoke. A single flashing red light ("E1") tells me that it can mean about a dozen different things. In we go. 

I decided to see mow much ignition I actually had: look near the center of the video below and watch for the flickering purple flame. That's the ignitor working well enough to tell me it's not the problem.

Better video available here: 
But let's back up. You'll need a few different Phillips head screwdrivers, a 10mm open end box wrench, rags, and if you're afraid of losing screws, Ziploc bags and a sharpie to label where everything goes. Power cord, fire extinguisher, safety glasses, & nylon or rubber gloves. Clear a workspace on a workbench if possible and clean parts as you go. Listening to some N.W.A. while you work will keep you smiling and confident. 

 Here is how the heater works - from the manual: 

"Fuel System : This heater is equipped with an electric air pump that forces air through the air line connected to the fuel intake and then through a nozzle in the burner head. When the air passes in front of the fuel intake it causes fuel to rise from the tank and into the burner nozzle. This fuel and air mixture is then sprayed into the combustion chamber in a fine mist. 

Sure Fire Ignition: The electronic ignitor sends voltage to a specially designed spark plug. The spark plug ignites the fuel and air mixture described above. 

The Air System : The heavy duty motor turns a fan that forces air into and around the combustion chamber. Here the air is heated and then forced out the front of the heater."

So, upon opening the sides (thermostat/power switch side and then cord wrap side), you can then remove the entire top cover and handle. Here are the heater components, all actually nicely laid out and serviceable. You can see that there's the pressure gauge, air pressure hose, fuel line going down into the tank below, an ignitor with spark plugs, the tube the flame exits, a photocell that looks impossible to remove (and is tricky), a fan and motor, etc... 

Suffice to say that I suspected a mere cleaning was all I needed to do. Years of bioDiesel use (I filtered it all well, never emptying a can into the heater for fear of adding bottom contaminants) all suggested that I needed to clean an orifice, fuel filter, fuel line, air filter(s) and whatever else may make this thing work. 

The first thing evident to me was a cracked end at the pressure gauge. I trimmed it after ensuring that there was enough tube remaining to recreate a tight fit. Pressure for this model should be 3.7psi, and there is a slotted pressure adjust nob near the gauge. Adjust this after everything is done and your heater works again.

The second thing I feared was that the photocell had become covered in a fine soot. I removed it (after removing the main firing tube and burner assembly) and gently cleaned it with a lint-free rag folded over the eraser on a pencil. Only mildly dirty. I made sure alignment was proper, too (see manual). The temperature control limit sensor was dirty and got cleaned, too. 

As with all things Diesel-powered, the fuel filter needs to be cleaned or replaced regularly. Since parts for this aren't available anywhere I found, I continued to pull the entire machine apart, separating the fuel tank, the motor and fan assembly, etc... I removed the fuel filter and blew it clean with compressed air, checking fuel flow by blowing through it both ways afterward. It didn't look dirty, but was, based on the different pressures before and after cleaning. Next, I got into the orifice (shutup, Beavis). It vaporizes the fuel that instantly gets ignited by the forked ignitor. I blew it clean for several minutes each way. I then removed that spark plug assembly. It's gap had widened, so I reset the gap to the specified .140", or 3.5mm. The average spark plug gap measuring device from Napa won't work. Use calipers.

Inside of burner assembly: orifice and ignitor/spark plug are visible.
DynaGlo Pro KFA70TDGP kerosens heater, burner assembly, orifice, & ignitor

I tightened the electrodes to which the plug wires attach, as they were surprisingly loose. The plug wires were in good shape and shiny. I drained the fuel tank, then rinsed with pure kerosene (which I never use), then drained it completely again. Definitely some gunk in there.

At the back of the unit, there are two air filters, one of which can be cleaned/washed, one of which needs to be replaced. I blew the latter out with the air compressor and it shot off a layer of the filter. Damn. But, I was able to save the rest of it and it's much cleaner. I cannot find filters anywhere. A piece of felt would work if you run your heater in a dusty environment. I gently cleaned the black room temp sensor with a lint free rag, too. 

So with the exception of taking apart the orifice assembly (which you can do, as depicted in the manual: you can even replace it at your local hardware store, too, in theory), I removed and cleaned everything inside the heater. 

And that's all it needed - a complete cleaning. Diesel stuff needs unobstructed airflow and fuel flow. Several times throughout, I tested the heater to see what I was accomplishing and which step exactly solved the problem. The top of the heater can easily be laid on the heater and the heater started up. Label the two spark plug wires - write right on them which one is the top and which is the bottom of you have to.

DynaGlo Pro KFA70TDGP kerosene heater ignitor

I was lucky the photocell wasn't dead - that doesn't seem easy to replace. Perhaps it is. 

I ran the heater on the gallon of kerosene for awhile, then filled the tank with B20. (I use 20% bioDiesel and 80% Diesel #2). I watched it awhile to see how it burned. Familiarity told me it was again working just fine. 

 That's it. Save your heater, save yourself a couple hundred bucks. Wear eye protection and keep that fire extinguisher handy : ) Remember that Elvis loves you; be open to His guiding hand. 

Let there be heat! 


Blogger Unknown said...

Very informative and helpful write up. Even though this is not the model I have the principles are the same. Thank you

9:19 AM  
Blogger Herry Johnson said...

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5:08 AM  
Blogger Unknown said...

Kerosene heater brings cozy space to your house.
Thank your very much the article.
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7:17 PM  
Blogger Unknown said...

I've just diagnosed mine. Same symptoms as this however the air pump is shot. It is a vein pump and lives on the back of the motor behind the airfilter. Romove it and check for wear. If it is worn you will notice the wear on the bottom as gravity helps the veins west out the housing.

3:56 PM  

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