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Author Topic: Lanair MX300 problem  (Read 7261 times)

jman2343

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Lanair MX300 problem
« on: November 15, 2013, 05:54:49 pm »
Unit was installed October 2010. 

About a year ago the unit started to act up.  One of the mechanics decided he would fix it but seemed he managed to get it to limp threw the rest of the winter months. 

What I found was the fire box filled with brown ash, quad ring mashed up, leaking preheater block, and filter in take clogged, lines blocked up and the preheater and air heater all blocked up and lower preheater element burned out with a hole in it.

It took some time but cleaned everything down to bare metal.  cleaned filters, lines, regulator, and pump screen.  replaced all O-rings.  Installed new quad ring and preheater.

There seemed too be a missing oring between the lower and upper block I found a 1/2 inch OD 1/16th oring that seems to be correct.

First try I had spark but could tell no oil, took it back apart and found I missed a blockage in the upper half right were the oil goes in from the lower block.

After cleaning it again the unit will only light if you turn the air pressure down to about 10 psi.  I've been on the phone with Lanair and they state that 10 psi will not over come the oil shut off plunger and air diaphragm to allow oil to flow. However it will light only this way, and the blower shutter is almost closed. 

Watching the target brick I see drops of oil hitting it and burning off.  I'm stumped and Lanair seems stumped as well, stating the air gauge on the regulator might not be right.  I believe it is.  I'm not sure what I"ve missed but open to any and all suggestions.

Just a run down, disconnecting feed line and running unit, oil does not blow out the feed port on the burner, there is a slight suction.  So from what I'm told there is no air leaks between oil and air passage (quad ring new).  Bypass regulator seated and pump running I get a flow rate of about 1 gal in 5 mins at the feed.  It doesn't make any sense, and don't wish to run the unit and risk target brick or fire box damage.     

jman2343

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Re: Lanair MX300 problem
« Reply #1 on: November 15, 2013, 09:45:12 pm »
Something came to mind.  I'm wondering if the previous repair attempts led to a smaller nozzle being installed....  Trust me I know this guy would do it.   The unit was somehow running with a bad preheater on the lower block plus blockage,  settings way off (air shutter open very little and lower air pressure settings on the regulator).  And unit wouldn't put out a lot of heat. 

There is a bag of parts and today I do remember seeing another nozzle in there with a bigger fuel orifice.  I'll have to see if I can get some numbers off it and then see which one is right.   

doug

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Re: Lanair MX300 problem
« Reply #2 on: November 17, 2013, 04:34:08 pm »
Jman,


 Welcome to the site. I like a guy that tries to answer his own questions. I'm sorry I have no answer to your questions I'm not familiar with commercial waste oil heaters. Please keep us up to date on your heater.

doug
You can't put it on the internet if it isn't true!

http://wasteoilheaterforum.com/index.php?topic=102.0

Russ

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Re: Lanair MX300 problem
« Reply #3 on: November 18, 2013, 10:27:12 pm »
Greetings Jman.

I'm in the same boat as Doug as far as knowledge on this commercial unit.  Did you learn anything about the nozzle size?


jman2343

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Re: Lanair MX300 problem
« Reply #4 on: November 21, 2013, 06:24:21 pm »
:) will do my friends. 

As it stands the previous nozzle was correct (the smaller ones installed, so the theory of someone messing with nozzle size was wrong ;D), however the unit is running better with the larger incorrect nozzle  :o...  Air pressure to atomize is closer to suggested starting spec of 18psil (with the larger incorrect nozzle in it..)   When setting these units the stated air pressure in the service manual is a starting point (in this case 18psi) right now psi is around 15ish.   It has been running all week with some smoke out the chimney at times and a miss on primary, it will auto reset after 2 mins and then fire, no manual reset was done during the week thus far (not that it means everything is good)  Right now feel like I'm playing hack-o burner tech  :-\

The run down as it stands  ::) Preheat block, upper nozzle gun, all filters (pump too), supply lines, firebox, heat exchangers and manifold box clean.  I have the new nozzle in hand with a new quad ring and will install that on Saturday.  The last thing I've noticed is the damper is not moving even on windy days it just sits there, while the other unit upfront a MX200 the damper is always moving with burner on or off.  I will inspect the damper, chimney and make sure the draft is correct (a friend by chance has a draft meter to let me use,  I just ordered a Dwyer Mark II).  should have -.02 cold and -.06 hot on the draft in the breech.   

I will report back soon.
« Last Edit: November 21, 2013, 07:06:58 pm by jman2343 »

doug

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« Last Edit: November 23, 2013, 07:02:49 pm by doug »
You can't put it on the internet if it isn't true!

http://wasteoilheaterforum.com/index.php?topic=102.0

jman2343

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Re: Lanair MX300 problem
« Reply #6 on: November 29, 2013, 07:02:02 am »
Yes Doug, its a lot to do, however after doing it once I'm sure next time will go quick and with less issues :)  It went 2 years without proper service.

I installed the new nozzle and cleaned the chimney out, also the damper wasn't moving (lot of ash behind it) and was set wrong.  Draft reading is taken 6inch from the damper and is now set to correct specs and the unit is operating like new.  Should only have to keep up on the filters during the winter.

Stinky Waste Oils

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Re: Lanair MX300 problem
« Reply #7 on: July 02, 2014, 04:02:18 pm »
Hi,

Service is very important for that model of Lanair. It sounds like you are on the right track though.
The correct nozzle for that MX is a -5. Lanair part number 9899.

Here is a link to many good videos showing how to service every inch of that machine.

http://www.westbrosinc.com/video/

https://www.youtube.com/watch?v=mbP08l5mBZU

https://www.youtube.com/watch?v=zMn7Hv87a24

https://www.youtube.com/watch?v=UeXOk9HmByY

There are more. You can find them.

 :D

You can't beat waste oil heat!