Burner Maint 101

Hotwaterwizard

Hotsy Service Tech
Diesel Burner Maintenance



Winter is over and it is time to think about tuning up your diesel burner on your Hot Water Pressure Washer. I will try not to get too technical here let’s keep it simple. The best tools you have are your eyes, ears, and nose. After all any seasoned mechanic is able to tune up a car engine or a lawnmower engine with these same tools. Of coarse you will need a couple of real tools to help with your tune up.
The two main brand names of burners I have found on most Hot Water Pressure Washers are Becket and Wayne burners. Both of these burners came from the home heating industry and are very dependable burners. Diesel burners are a lot simpler than you would think they were. You need the same things that you need to make an engine work it is very basic. You need Fuel, Air, and spark to make fire. So lets start with the Fuel. Check the fuel tank for sediment in the bottom. The easiest way is to empty the tank and clean it out. Pull all of the fuel lines and barbs off and clean it out real well. Most burner problems start with the sediment being pulled thru the fuel lines and plugging up the filters. When you are done with this step you should check all of the fuel lines and make sure they are not brittle. Most of the Pressure Washer Manufactures use clear braided ¼ hose for the fuel lines and they get brittle and crack then air will get sucked in with the fuel causing poor combustion. I would suggest replacing those hoses with ¼ fuel line found at any Auto Parts store. The investment will be money well spent. Replace the fuel filter at this time as well. The fuel filter traps all of the junk that gets in the fuel. Replace it even if it looks good. Now here is a secret that most people don’t know about. Inside of the fuel pump is another filter. See the 4 screws on the fuel pump? They are 5/16 screws. Remove all 4 and be careful not to rip the gasket.







Remove the cover and clean out the mesh screen filter with air or gasoline or break cleaner. Now put it back together. At this point make sure all of the fuel lines have clamps on them. Don’t use those cheep plastic or spring style clamps they will give you problems in the long run. Use the hose clamps that you have to turn the little screw in to tighten them. They stay tight when you install them and you can tighten them more later on down the road when you are checking your clamps periodically. Get the stainless steal ones if you can. Now we move on to the rest of the burner housing. See the small copper tube that runs from the fuel pump to the rest of the burner? This is important, Always use a wrench to remove this fitting! It is a 7/16 open-end wrench. If you use a pair of pliers or vice grips you will damage the fitting. Now that you have the tubing loose you will find a nut holding the nozzle and electrode assembly in. Wayne uses a 9/16 nut and Beckett uses another kind. Remove that nut. Now look at the transformer. It is located on top of the burner housing. Wayne uses a ½ inch screw on the side held on by a silver bracket. Beckett uses screws located on the end closest to the flange of the burner mount. Both types are hinged so you can open them easier. Open this up and remove the burner gun assembly. Replace the fuel nozzle. It takes a 5/8 wrench to remove the nozzle. Put the same size nozzle in that came out. These are cheep enough to just replace them. It will save you trouble in the long run to just go ahead and change it now. There is a tiny filter on the end of the nozzle that gets plugged up.
Now for the electrodes. These things need to be adjusted to get a proper spark. The adjustments are better explained with a picture.

Now put the burner gun assembly back in very carefully to avoid getting them out of adjustment. Put the nut and the tubing back on. Close the transformer carefully while peaking in to make sure the transformer lines up with the bus bars. If not adjust the bus bars carefully so they line up. Now close it up and put the screws back in. At this point we can put Diesel back in the fuel tank and fire up the burner. If it does not burn right away.
There may be a few adjustments we need to do. You may need to prime the pump at this point. Use a 3/8-inch wrench to prime the pump; opening the zirk fitting on the right hand side of the fuel pump, it looks like a grease fitting. When fuel starts flowing in a steady stream the pump is primed, close the zirk fitting, and the fuel will be diverted back to the fuel nozzle and it should burn.
Here’s where your eyes and nose come into play, look at the smoke, if it’s black that means its not getting enough air, and you should adjust the air band. If the smoke is white, it’s getting to much air, adjust it back and forth until it runs clear.


If the fumes are burning your eyes and nose it is getting too much fuel, and you need to adjust it by turning the screw located above the zirk fitting, use a straight slot screwdriver. Clockwise is more fuel, counterclockwise is less. If the burner still will not operate properly check the burner coils for soot build up. It will be where the exhaust flame comes out of the burner. Excessive buildup will cause the burner to choke off the airflow. You can clean it out with an air compressor or pressure wash it out. If you get no burn at all you may not have any spark and you need to check the High Voltage Transformer to see if it is putting out a spark. This is the most dangerous part of the whole process, you are dealing with High Voltage of 10,00 volts! Open up the transformer like you did before. Leave it loose and get a large well-insulated screwdriver. Start up the machine and use the screwdriver to short out the transformer output terminals then pull the screwdriver back still touching one of the terminals and see if you can get the spark to pull at least half way between the two terminals. If you can’t then the transformer is bad and it should be replaced.

John DeRosa (Hotwaterwizard)
Hotwaterwizard@aol.com


This Article is in Blastmaster Magazine. With Pictures included.
It is also on my website under Documents section.
 
I am the Branch Manager of Steam Cleaners Inc. in Stockton Ca.

In the past few years I have replaced dozens of 12-volt Igniters on the gas powered Hot Water Pressure Washers. They seem to have a defect in their design. I think their design is not the problem. I think the way they are wired is the error in the design.

I have over 25 years experience in Electronics from Car Stereo repair to F15 Fighter avionics systems.

In my opinion the problem is as follows;
(#1)The 12-volt Burner Motor, Fuel solenoid, and burner relay.
(#2) The engine Voltage Regulator.

A DC motor has permanent magnets and windings. When you turn off the motor it acts like a Coil in a Car. As the field collapses it produces a voltage spike just like the Car Coil does. When you apply a voltage to the coil it does not produce the spark for the spark plug. When you take away the voltage the field collapses and the spark is produced. That is why the engine has a rotor, to turn the 12-volts on and off so the field will collapse and produce that spike. On a Pressure Washer that spike is not desirable. The motor will produce a voltage the same way that the Car coil does so will the Burner Relay and the Fuel Solenoid. They are all coils as the field collapses in all of them a spike is produced for a few seconds. If you want to believe, do this test, hook the shaft of the Motor to a Drill and spin it with a voltmeter on the two wires. The motor will act like a generator. It will produce a voltage. This test proves my theory. Another test you can do is to touch the relay coil wires as you turn the DC on and off. DC voltage does not shock you but the spike of the field collapsing in the relay will bite you pretty good. The good news is the solution to the problem is simple and cheap. Just add a Clamping Diode across all of the coils and the spike will disappear like magic. Part# ECG5817 or NTE5817 should do the trick.








Now for the other problem.
The Voltage Regulator on the Engine puts out about 14-volts. This is so the battery can charge. If you take a look at the specs on the Igniter they all say 12-volts not 14-volts. That means there are two extra volts on the Igniter that aren’t suppose to be there. This will cause the components to over heat and draw more amps than they are designed for. This will in turn cause premature failure of the components inside of the Igniter. There is also good news for this problem as well. Just add an aftermarket Voltage Regulator in line just before the Igniter. Only use it on the Igniter. It cannot handle the current of the motor. The part # is ECG933 or NTE933 It is a 12-Volt 5-Amp fixed regulator. They use them in power supplies. They need a heat sink.

On the following page is a suggested wiring diagram for the modified burner.

Sincerely John DeRosa
Branch Manager
Steam Cleaners Inc.
1115 E. Waterloo Rd.
Stockton, Ca. 95205
Hotwaterwizard@aol.com
 
hi john.

can you tell me where your website is please, as the help you give out is great and i would love to browse your site .

cheers paul.
 
paul-uk said:
hi john.

can you tell me where your website is please, as the help you give out is great and i would love to browse your site .

cheers paul.
Your Email Address is not listed in your profile.
If you look at the bottom of every post you will find a little house symbol with www on it. Just click on the home and you will go to the website that belongs to the person that made that post.


My website
 
Back
Top