trouble igniting

[dutchboy]

I found a used Wedco Model L, rated at 200,000 btu, hung it in my shop and used it without any trouble for 3 seasons before this fall.  I always thought that I was getting away with something the way it worked without monkeying with it hardly at all.  But this season, it failed to stay running when I put the temp down to the minimum stat setting at night.' 
Knowing it hadn't had the maintenance that it should have, I took off both sides of the unit to give the heating chamber  a good cleaning.  I then pulled the injector out and cleaned it, checked the gap at the electrodes and made sure they were aligned as well as possible.  I'm able to see the spark when it fires, and I know there is oil present.  I'm
just not able to see the spray very well.  At the times I did have it showing a healthy flame, I could come back to check later and it would have changed to quite a degree, sometimes smaller flame, sometimes much bigger.  I found some junk in the opening right behind the injector nozzle, but I believe everything is out now.  I just haven't been able to get it to fire back up at all.  Any thoughts?  Thanks

[ShopSpecialties]

You are definitely due for a burner rebuild. The burner needs to be completely disassembled and the pre-heat block scrubbed out until it is shiny on the inside.   

[dutchboy]

Thanks,

I somehow had overlooked a tiny orifice in the injector.  Got it burning like before.  Don't know how it got plugged, but
that's all it needs now.  In the meantime I've got a new filter on the pickup in the tank.  I'd been using it all this time with a straight unfiltered pipe. 

Thanks for the reply.

[ShopSpecialties]

Nothing will get by the filters to plug a nozzle. Nozzles plug from the oil slowly baking over time in the pre-heat block that is always maintaining 140*. Every manufacturer recommends burner rebuilds every year where I say every 2-3 years as long as the power is turned off in the Summer.

[dutchboy]

I am fortunate to have the manual with this used unit and it has served me well.  The manual states that in the unlikely event the preheater block needs to be cleaned, it should be removed and sent back to the manufacturer.  Any way around that in your experience?  I thought about pulling out the elements.  It has two.  The manual warns against taking the steel allen head plugs out without heating up the aluminum first and then only after taking the block itself out to begin with.  The elements are built of steel as well so I am hesitant to try to pull them out or I'd start there.  Thanks.

[ShopSpecialties]

I have been doing nothing but waste oil heater sales and service for 23 going on 24 years. Burner rebuilds are normal heater maintenance. If you are plugging nozzles with black carbon then it is from the preheat block. You can clean the preheat block yourself and save money. Remove the block and put it in a vice. Heat up the plugs with a small torch and also heat around the elements so they come out easy. Gun cleaning brushes work good in cleaning the passages. Make sure you get it shiny on the inside and leave no carbon behind. When you go back together blue medium strength Loctite on the threads of plugs and heating elements tighten till snug.


 

[dutchboy]

I gave myself a full day's lesson on disassembling and cleaning the block.  You sure sent me in the right direction.  Thanks for the help.  Tomorrow I get to put it back together.  Good thing I have a wood stove in the far end of the shop.
It will help a little bit, but it can't handle the really cold temps that are coming.

[ShopSpecialties]

Make sure you put a new o-ring on the nozzle holder while you have it out.

I am here to help so please feel free to ask any questions you might have.

[dutchboy]

Back together and working well.  I did replace the O ring on the nozzle holder.  Thanks for the help.  I've been wondering how long I could get along without having any trouble with this heater.  From what I seen inside that block it's a wonder it ever worked at all.  Good to know that I can maintain it myself.  I used it for at least three heating seasons.  Now is the first time that I've ever had a filter in the tank.  Thanks again.