Last year I had a whole bunch of issue where my furnace would periodically stop working when it got very cold. I had a bunch of furnace guys come out and the final consensus was that the fuel feed was partially clogged and had to be replaced. They would replace the 1/4" with 1/2" copper. The plumber came out and when he took the old tubing out there was about 3" of ice clogging the end of the tubing. We have a horizontal tank with 2 tubes running to the top of the tank. He stated that when installed the tubing was placed too close to the bottom of the tank and when the water turned to ice, it clogged the system. It looks like the water got into the tank because fuel gauge and its washer had rotted leaving a nice wide open hole. After he finished everything worked fine.

This year I called the same plumber to remove any water in the tank and a guy came out, stuck a steel pipe into the tank, swirled it around, and pulled the pipe out. After looking at the pipe he said there was no water in the tank. However, he did recommend that the tank be leveled because 2 of the tank's legs had fallen off the cinder blocks they were sitting on.

So I jacked up the tank and repositioned the cinder blocks under the legs of the tank to get it fairly level and now during the first below-freezing night, I'm getting the same symptoms of last year of when the furnace would eventually stop running. The flow control flap on the vent will start flapping back and forth for a day or so, i believed indicating a lack of fuel flow, and then the furnace would just cut out.

I'm concerned that when I "leveled" the fuel tank, the water that was resting at one end is now spread along the bottom of the tank. This water is now getting back into the fuel flow and causing the furnace to cut out again.

Does anyone have any suggestions on what I can do? Thank you.