Heating oil shelf life

Old 03-12-23, 06:31 AM
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Heating oil shelf life

I replaced my 40 year old boiler and oil tank last year. We are nearing the end of the heating season and I'm trying to decide which is best - I can either fill the tank now or wait until fall. I know that the oil will still be OK in the fall but my concern is leaving the tank almost empty over the summer. Do I need to be concerned about condensation in the tank?
Old 03-13-23, 08:47 PM
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Where is the tank .... inside or outside ?

Condensation shouldn't be an issue with a tank in the basement.
Different story if it's outside.
Old 03-14-23, 04:49 AM
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SHORT- Fill the tank now so the thermal mass of a full tank of oil prevents condensation; add a bottle of Dry-Gas if you're kinda-worried, and cover the vent with an old soda bottle (tractor style) so water condenses on the bottle, and drips down onto the outside of the tank, not inside the tank.

LONG- it's a new tank- I wouldn't be too worried about condensation, most oil tanks have an allowance for the buildup of water + oil = sludge, by raising the intake off the very bottom of the tank.
Over many years as a Realtor, I've heard all sorts of ideas about how to deal with condensation in an oil tank:
Some rely on dissolving the water into the oil so it doesn't build up e.g. add a bottle of Dry-Gas or a bottle of rubbing alcohol, or a bottle of diesel injector cleaner.
Others swear by limiting the temperature swing- e.g. paint the tank white so it doesn't heat up / cool down as fast, enclose the tank in a plastic storage shed to prevent termperature swings, Or install it on the north side of the house to avoid the temperature swings that cause condensation,
Then there's the 'remove the water" camp- install it on the south side of the house with gravel around to avoid moisture by creating a hot-dry micro-climate. A version of this is 'displace the air'; drop naphthalene / a mothball into the tank to drive out the air / moisture; or drop in some dry-ice so that the tank gets filled up with heavier-than-air COČ which displaces the air.

Personally, I have an outside oil tank up against a west-facing stone wall.
I just keep the grass under & around the tank short and occasionally rake it down to dirt.
I addressed condensation by cutting the top off an old 2 liter soda bottle and placing it over the tank vent. Reason #1 is to keep the vent and the around it dry, #2 is that the thin plastic walls of the bottle chill down quickly, so any condensation occurs on the outside of the bottle, before it can get inside the tank.

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