Removing An Old Oil Furnace: Draining and Disposing of Unused Home Heating Oil

By Bruce W. Maki, Editor

In the fall of 2002 our oil furnace began acting up, and instead of fixing it or buying a new oil furnace we switched to propane. For more about the decision to switch fuels, read Killing The Fuel Oil Furnace. 

Once the propane furnace was installed, we dismantled the oil furnace and hauled it out in pieces. But the oil tanks were another issue. We had about 100 gallons of oil in the tanks when the furnace conked out. I asked our fuel oil supplier if they would buy back unused fuel oil. "No", they said, but for $100 they would pump out the tanks and haul away the fuel oil.

Luckily I had the foresight to save the oil burner pump unit from the front of the furnace. I knew I might find it useful for pumping something.

Pumping Out The Unused Oil:

The old oil tanks in the basement.  There were two tanks, about 250 gallons each. There were big 2" steel pipes for fill lines, and 1¼" steel pipe for vent lines. This all had to be removed eventually.

My initial thought was to use the burner pump I salvaged from the old furnace to pump oil into a 5 gallon fuel can, and then carry the can outside and pour it in a 55-gallon barrel. I realized that this would entail 20 trips up the stairs, but this was only a one-time job.

I rigged up the old burner pump. I put the pump on a chair and re-connected the oil line from the tanks.

Of course, the pump needed an electrical source. I was going to just connect an old power cord to the pump motor, but I thought that I might find it awkward to unplug the unit if, I had to hastily turn it off. So I attached a metal electrical box to the pump motor and hard-wired a simple light switch. I used an old electrical cord to supply power to the switch. I could just flip the switch to activate the pump.

I positioned the pump outlet line (arrow 2) into the fuel can. Arrow 1 points to the incoming supply line from the oil tanks. Note how the supply line is 1/4" copper tubing, while the outlet line is only 1/8" copper tubing.

Yellow fuel cans are for diesel fuel, which is the same as heating oil, just taxed higher.

I turned the pump on and a stream of oil shot out (red arrow). Well, actually I had to bleed the air from the pump first, which is required whenever the tanks run dry or the supply line is disconnected.

BUT...

It took forever to fill up the 5 gallon can. Actually, it took 20 minutes. That would be a total of 400 minutes (almost 7 hours), and I would need to remain nearby so the fuel can didn't overfill. Sitting around and watching an oil can fill up did not appeal to me.

I had parked my utility trailer just outside the house, with two empty 55 gallon barrels placed just ahead of the axle. Since fuel oil weighs around 8 pounds per gallon, these barrels are going to weigh over 400 pounds each when filled.

So I dumped the plastic jug of oil into a barrel and started to consider other approaches.

I had parked the trailer right in front of the oil fill pipe. Since these pipes were being removed, I figured they would also make a good way to get a hose out of the house, instead of running a line through a window or door. As a thunderstorm loomed on the horizon, I drove to my local Ace Hardware store and bought some parts.

Using a big pipe wrench, I removed the vertical pipe and fittings from the vent line. However, I was not able to rotate the pipe that went through the basement wall. So I went inside and cut the other end of this pipe with my reciprocating saw and a fine-toothed blade. Then I ran a long piece of 1/4" polyethylene plastic tubing through the vent pipe.

I placed one end of the tubing in the opening of the barrel.

Since it was starting to rain, I placed a block of wood over the hole. This also held down the tubing so it wouldn't fall out. I knew I would have to leave this unattended for a while, and I didn't relish the thought of oil spewing all over the ground.

Back Indoors:

I removed the outlet line from the pump.

I was not able to buy an adapter for the 1/8" flare fitting, so I removed the elbow that the outlet line was connected to.

Luckily I guessed correctly that this elbow screwed into a 1/8" NPT (tapered pipe thread) fitting.

I had bought several adapters, just in case. The adapter that I needed had a 1/8" NPT thread on one end (the right hand side) and a 1/4" compression fitting on the other end.

I screwed the adapter in the outlet port of the pump. This is a small fitting and took only a very small wrench. I wasn't worried about leaks, so I tightened the fitting just a bit.

I placed the compression nut and ferrule on the end of the plastic tubing. I didn't realize until later that I forgot to get the little brass "T" insert that is supposed to go inside the end of the plastic tubing. This insert prevents the plastic from deforming if the compression nut is tightened too much, which I seem to do every time.

I placed the tubing into the adapter and tightened the compression nut. I realized my mistake as I was tightening this nut, so I stopped.

With the plastic tubing connected, I turned on the pump, and red-dyed oil started flowing.

This is where the tubing exited the building. The red arrows indicate the section of vent pipe that I removed. I made a cut about 4 inches from the elbow, and then I used a pipe wrench to unscrew the short piece of pipe.

I figured this connection would leak a bit, but it didn't. I suppose because the other end of the line was open, the pressure in the tubing was quite low.

At the other end, fuel oil flowed into the barrel.

What you can't see from these pictures is just how slow the fuel flowed from this tubing. Furnace oil pumps are meant to create fairly high pressure (about 150 PSI) to spray oil into the combustion chamber. Our old furnace had a spray nozzle rated at 0.85 GPH (Gallons Per Hour). The nozzle capacity dictates the consumption rate of oil.

Without the nozzle restricting flow, the pump can deliver more gallons per hour, but it is still a slow rate. I occasionally went outside to check on the fill level in the barrel. It took about 6 hours to empty the oil tanks.

While the pump was working, I dismantled the fill and vent piping. There were a couple of union fittings that I could disconnect.

Prior to this task, the biggest pipe wrench I owned was a 24 incher. Never one to miss an opportunity to get a new tool, I bought this big 36" aluminum pipe wrench ($87 at Tractor Supply Co.).

I needed this monster pipe wrench to hold the 2" fittings, though my 24" wrench could (barely) grab the 2" pipe.

After disconnecting the unions, I removed the supply pipes from each tank I also had to use the Sawzall to cut the big 2" fill pipe where it went through the basement wall, since it was too difficult to turn with all the mortar holding it.

Disposal:

The next day I strapped the barrels to the trailer to haul them away. These are basic 1-inch ratcheting tie-down straps with hooks on the ends.

Not being sure of which day I would be able to haul away the oil, I did the filling of the barrels with the trailer disconnected from my truck. I thought I might have difficulty hitching the trailer to the truck with almost 900 pounds of steel and oil on board, but I was actually able to move the trailer a couple of inches without tearing all the muscles in my back. The alternative would be to use a hydraulic bottle jack to lift and lower the tongue of the trailer. Or get a helper.

I placed a block of wood on top of the two barrels, so the strap would hold better.

I used 3 ratcheting tie-down straps: One over the top, one in front, and one behind the pair of barrels.  In Michigan if you spill fuel on a public highway they'll give you a big 'ol fine, call the HazMat team, and bill you for the cleanup cost.

These one-inch wide straps are rated at 1,200 lbs breaking strength (I think).  I never use rope anymore for tying down loads.

To be doubly sure the barrels would stay put, I  placed some scraps of 4x4 against the barrels, and pinned those in place with other blocks of wood. I did this on both front and back.

These barrels didn't move an inch. I only had to drive five miles. A few weeks before this, my local metal recycling company mentioned that they had a furnace that burned waste oil, so I offered them the unused heating oil. They lent me the barrels, so it was a deal. It would be nice to get some money for the oil, but we just wanted to get rid of it.

Continue To: Removing The Old Oil Tanks

Copyright © 2003, 2006 HammerZone.com

Written April 18, 2003
Revised (formatting) March 15, 2006