(2) 275 gallon heating oil tanks questions?

jamoka3

New to the forum, and new to owning a home with heating oil tanks.
Have a few questions...
(See attached pic.) Is the tank on the left which has my fill pipe attached supposed to be more full then the tank on the right? The right tank has the vent pipe. The left tank is about 4 inches from the top, I pulled the center plug to see, and the right tanks about 14" lower...
Curious to know, because the right tank has my fuel gauge and its never above 3/4 full even when its topped off. So I assume the left tank is my "main" fill tank and the right tank is the secondary tank?
Both valves seem open on the bottom . And they both tie into the same feed pipe under the tanks to the boiler.

Intplm.

Yes @jamoka3 . The left hand tank in the picture will fill a bit more because it has the fill pipe directly piped to it.
The way these tanks are twinned together will make the vent whistle / vent alarm stop a little early. Leaving the tank with the vent attached with less oil.
In some areas this piping arrangement is no longer allowed by code. The new codes would have each tank piped with a separate fill and a seperate vent.
Your piping arrangement looks fine however and should not pose any other concerns.

HVACNUT

In addition to what @Intplm. said, the levels between the tanks should equalize after a while from the crossover on the oil lines. It's not uncommon for the crossover to get clogged. But that usually leaves one tank full and one tank empty.
And unless someone has the same exact basement and oil tanks, you've posted that pic here in the past.

EBEBRATT-Ed

Don't know what your looking for. This has been asked and answered as those tanks were posted on here previously

STEVEusaPA

EBEBRATT-Ed said:

Don't know what your looking for. This has been asked and answered as those tanks were posted on here previously

I thought they looked familiar. They are still allowed by code to pipe with a crossover. What is needed are swing joints on the supply and vent piping. And proper spacing.

jamoka3

This is the first time I asked this question... and yes i have posted this pic Before. This pic was saved on my phone and was the best one to show my tank layout.
That was the first time i ever posted, and asked what size tanks they may have been, since they are painted over and there where no identification tags with tank capacity.

STEVEusaPA

With the tanks piped in series your situation is pretty common.
Most likely with 2 tanks, the delivery driver is filling at high speed, and the crossover is causing foaming, which is stopping the whistle sooner. Slower filling may get a little more in the tanks.
You also have to leave room for expansion especially in the dead of winter when you get a 20 degree temperature oil fill into your tank and it warms up to 60-65 degrees.

HVACNUT

@Ron you need to read all the posts, not just the first one. I know we get a little drab sometimes, but there's some good info up there. 😘

STEVEusaPA

DANGER! DANGER! Please make sure you have those plugs you removed doped and re-tightened on those tanks, especially the left tank.
The whistle won't stop (might not even much noise).
Your insurance company won't pay a claim on it and put all the liability on you. And probably the oil company's insurance won't pay either if you touched it.

We had a thread before about a guy who was really really obsessed(?) with wanting to know exactly how much oil was in the tank.
Think of that oil gauge like your car gauge. You have to figure out what 'full' is and what 'empty' is. The gauge is more like a pretty good indicator.

Easiest is to deal with an oil company who will put you on automatic delivery, track you usage, fill your tanks. Simply done by getting 2 complete fill ups, and putting the required info into a computer to calculate fuel usage basically the same way you track MPG in your car--fill up, drive so many miles, fill up, do some simple math.

I have hundreds of oil customers on auto delivery and they never run out. And they get a better price as I can forecast and schedule deliveries their deliveries more efficiently.

STEVEusaPA

@ron I think you do not fully understand how the crossover works.
The tank on the left is connected to the fill, the tank on the right has the whistle and vent.
The tank on the left fills completely up then the oil is pushed via the crossover into the tank on the right. The whistle blows the entire time.
When the tank on the right gets about 7/8's full the whistle stops.
So tank on the left, full 275 gallons, tank on the right about 240 (if filled fast) to 250 gallons.
Settled out total volume will be around 500 gallons.
Separate fills wouldn't increase the total volume as now both tanks will end up with about 240/250 gallons each.

I personally don't like this set up, even though it's allowed by code, and at minimum I will always do 2 fills, and one connected vent.

Either way they are piped, best to draw them both down together, and fill them together. Trying to work off one or the other, and you'll probably end up running one dry and will have to re-prime the system. And it will probably happen right after you left for the weekend...yikes!

Alan Welch

Unless you just had a delivery , both tanks should be equal. Even the crossover pipe should have swing joints as well.

Alan Welch

Ron, to be blunt, your wrong .The oil gets filled into the tank closest to the wall. Any air gets pushed into the second tank. when the first tank is full the oil goes through the 2 inch pipe into the second tank. when the oil in that tank reaches the stem on the whistle vent, the whistle stops. the 1/2 inch or 3/8 inch line beneath the tank is the equalizing line . if the tanks are not equal the day after a delivery, either the equalizing line is blocked or a valve is closed.