Joe wrote:

I tried to replace the tank gauge. I think this tank is about 50 years
old and the gauge started to fall apart when I tried to twist it. It
also looks like there is some kind of grey sealant that has welded
itself to the threads over the years. There are no other available
holes on the top of the tank. There is one where the oil comes in and
another where it goes out. The tank was inspected when I bought the
house and was declared in good shape. As far as buying oil is concerned
I was offered a plan in the fall but the prices were too high back then
- about $2.70 per gallon so I have been buying the oil from a
wholesaler for $1.99 but he doesn't do schedules and you have to call
him to fill up. I'm just wondering if every two months is about
standard. The last thing I want to do is run out and have my pipes
freeze.

You simply can't go by a number of days between fill ups since your
consumption is not a constant.

The software the oil companies use takes heating degree days into
account along with your past usage to determine a gallons to degree day
ratio for your account. By tracking the degree days since your last fill
up and knowing the size of your tank the software schedules the next
delivery. I'm not aware of any similar tracking software for home use.

Have the tank gauge replaced when you have your burner's next annual
service. It shouldn't add much to the cost of the service call if you
tell them in advance so they have the part with them.

As for checking the level now, if there are no other ports on the top of
the tank you can use you won't be able to get an accurate reading
easily.

You may be able to use one of the stick on level gauges intended for LP
tanks to get a decent reading. They only cover a short range so you'd
want to stick it to a fairly low point on the tank, perhaps 1/4 of the
way up the end. These gauges are basically liquid crystal thermometers.

The way they work is you pour a little hot water on the gauge which
causes it to change color. In a few seconds it starts to change back as
it cools. Since the tank surface that is in contact with liquid inside
will cool more rapidly you will see that area change back first
indicating the approximate liquid level.

The LP gauges work reasonably well on steel LP tanks so they should work
ok on a steel oil tank. They are also cheap so it's worth a shot since
your other option is to tap the tank and try to find the liquid level.

For backup against having your pipes freeze, you can get two 5 gal cans
of diesel fuel to keep as a reserve. Diesel fuel and home heating fuel
are basically the same other than red dye in the untaxed heating fuel.
Heating fuel is also known as "off road diesel" and frequently used for
construction equipment that is only operated off road and not subject to
transportation fuel taxes. 10 gal would be enough to keep you going
until a next day oil delivery.