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Changing oil furnace to 2 line

7376 Views 7 Replies 4 Participants Last post by  tk03
I have a Beckett AFII oil burner. The tank is lower than the pump and I can only run a couple minutes before it gets air in the pump and have to bleed it out again. Manual says to use two pipe system if tank is lower. It also says to insert a plug in the pump. Where does this plug go? I am trying to attach a pic of the pump. I think the bottom two fitting are in and out, so after I find where to put the plug all I have to do is run a line from the outlet back to the fuel tank? TIA


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Bottom right.

How far below the burner is the tank?

Even when the tank is slightly below the burner/pump, the pump can still pull the oil up.

But, if you have a slight air leak. it will quickly lose its ability to maintain its prime, and the burner will shut off.

Switching it to a 2 pipe system. Will cover up th air leak for a while. But, it can still lose its prime when the burner is off.
And may not be able to pick it up quick enough.
It is less than 2' lower. You say the plug goes in the bottom right fitting? There is already a plug in there, could that be the problem? This is a used Lennox furnace, not sure how it was set up. The manual says it is set for the single line from the factory, but don't know if it has been changed.
The plug you see is a pump port plug.
Not a bypass plug.
The hex plug must be removed. Then the allen head bypass plug gets screwed into the small port inside the pump, and the new return line ran.

Sounds more like you have a leak in your oil line set somewhere.
are there any joints in the oil line also make sure if you have an oil filter (and if you dont you should have one installed) that the bolt on top is tight
Thanks everyone....

I will check those things this week end. By the time I get this done I won't need it. LOL
Found the problem

It was my shut off valve. I back tracked from the pump, running a line into a can of fuel. When I got to the valve it would suck air. I put a straight fitting in and it worked fine. I got a new ball valve and it went back to sucking air. Yesterday I picked up a new gate valve and it works fine now. The ball valve had a large body to it but it said it was a 3/8 valve. Don't know why it wouldn't work. Thanks for the help.
Check this link on two pipe systems
2 feet should not be a problem. I also believe it is an air leak. The pump should be able to handle 5 ft or more.
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