Cold weather and outside tanks

StaggerLee

So I was wondering about what is happening to oil in cold weather. We are in a cold snap , lowest temps with wind chill are about -10 to -15. I’ve read that No.2 fuel oil will start to gel at -20. Past two days all service calls were outdoor above ground tanks and locked out primary controls. No oil at burner. All filters and pump screens were checked and replaced as necessary but none were blocked enough to account for blockage. Used co2 gun to “ unblock” lines and after doing so, all fired up, ran 20 minutes , ran analyzer , cycled a couple times.Only one customer had just gotten oil so maybe that one may have been gunked up with sludge but, all the other ones?
So does anyone have an answer if what I read was wrong or could it have gelled up at that temp? Any response is appreciated for my own knowledge……. Knowledge is power

SlamDunk

Could it be water? High summer humidity through tank vent condensing in tank and sinking to the bottom then freezing.

StaggerLee

This has also crossed my mind, a black oil tank outside for years will eventually get some type of condensation on the inside of the tank at some point throughout the year.

EdTheHeaterMan

Here is something that you may want to read about outside above ground oil tanks and the wya the fuel line is connected to the tank before it goes into the home.

https://forum.heatinghelp.com/discussion/comment/1737746#Comment_1737746

Jamie Hall

The fuel, if not treated for cold weather, can gel enough to defeat you at those temperatures. Ask anyone who drives a diesel vehicle… If you can get it moving, it will usually continue. Until the next time.

techforlife

I think fuel gelled in the line enough to stop the flow. The line, being much smaller than the tank, gets colder quicker, gelling the fuel inside of it way before the tank gels. Fuel in the tank should be routinely treated with a quality pour point depressant/ water dispersant at fill up. Also available is an oil tank heater. I think Skully makes one, then you could insulate the line.

EdTheHeaterMan

My go to service call on cold oil tank no heat calls is to use a. https://www.fwwebb.com/product/Westwood/Hand-Pump/T30W/253699 and a container of fuel oil treatment.

1. I would connect the pump outlet to the fuel line and connect a suction tube to the inlet of the hand pump.
2. I would then force air into the fuel line and build up some pressure if the tank line was blocked with ICE from condensation.
3. Then take a heat gun and thaw out the fuel line. once the ICE was melted, you would hear the air bubble into the tank. Now the fuel line is free
4. Go back inside and put the suction tube in the bottle of fuel tank treatment. pump the treatment thru the fuel line. That puts the chemical in the tank where it will do the most good.
5. pump more bubbles into the tank to agitate and mix the fuel chemical up in the bottom of the tank near the fuel line suction opening.
6. Remove the hand pump and put the fuel line back to the oil burner fuel pump.
7. Prime the fuel pump.
8. Fire the burner.

This solved the problem until Condensation found its way back into the fuel line on the next fuel delivery. In cases like this, I would reconfigure the fuel line that following summer so there were no low spots that could trap water at the low spots outside where it could freeze

Here is a link to a video of how water will stay at the low spot in a fuel line and the oil will migrate past the water. when the burner starts watch the water move up the tube slightly and watch closely for the oil micro-droplets move thru thru water https://drive.google.com/file/d/1tcb-lS6a1Bi6caVZIG90f4AdvMTaQ2Du/view?usp=sharing

Let me know if you can't see the video

ethicalpaul

When I lived in Michigan I had an external tank with an exposed copper feed (exposed for about a foot before it went underground).

One severe cold snap in 3 years I did have to pour hot water over the feed line once to get it moving. I have no idea if it was water or just sluggish oil, but that is my one anecdote.

My mother's house in southern NY state has an external tank with an exposed copper line as well and it has not failed in 4 years so far. Her winters are slightly more moderate than the Michigan ones I think.

techforlife

EdTheHeaterMan is spot on. That is the approach I have used for over 40 years. Should be required reading for all service techs. Another preventative idea I have used is to run the suction line from the top of the tank a few inches off the bottom. Have a valve (with a plug in it) in the bottom outlet so any accumulated water/ sludge can be drained out in warmer weather. Always have tank pitched towards the outlet.