I'm at a loss. I can't figure out why my gas bill is as high as it is,
while my neighbor's bills are MUCH lower.

I moved into this house a couple years ago and I've had sticker shock
every time the gas bill arrives. The new house matches my old one as
far as appliances as I brought them with me. The only difference is
the furnace and water heater.

As an example; the largest bill I've ever had at my old house was $125
where the largest bill to date at the new house was $320. The house is
bigger by 600sqft but that should only account for winter bills...

I use to think the old furnace was the culprit but my bills are high
all year around. (I even replaced it without much effect) A typical
bill at the old house was $12-$20... the new house never has a bill
below $100, even when the furnace is off all month!

I started suspecting that the meter was bad so I had NIPSCO come out
and check it several times until they replaced it on my insistance. It
didn't help. While they were there they checked of leaks too.

I just talked to the old owner of the house and found out that he too
had the meter swapped. So even he knew something was up.

So my gas bill last month was $101 and my neighbor's bills average $25.
I don't know what to do next. The only thing left to try is replacing
the water heater but I can't imagine that it is even capable of using
that much gas.

The NIPSCO guy shut the water heater off for 20 minutes and checked the
meter. No gas was used. This weekend I'm going to shut it off for a
few hours and see if the meter moves. When I relight the water heater
I'm going to see how much it consumes over X amount of time in case
it's a leak after the shut off valve.

In the meantime, I'm open to any suggestions. If my natural gas bill
goes down, I might be able to fill my car up with the savings!

Thanks for reading this long post.