If the apartments also get gas for other appliances from a different meter
(or separate meters) I would check that one of your helpful neighbors hasn't
tapped the community hot water gas line into the one that serves their
apartment.

Happened to me 20 years ago although I was able to get the guy charged with
theft, the gas company wouldn't take off the extra $120 in gas usage off of
my bill.

Jon


"Bettina" wrote in message
news:Eycqf.1288$0u5.665@trnddc01...
We live in a six-unit apartment building, and all units are served by a
single water heater.

Last month we had a sudden increase -- about 25 percent -- in gas usage.
Emphasize, USAGE, not price -- which also increased.

The water heater is around 10 years old. Do such heaters lose efficiency
with age?

There is no other gas appliance on this meter.

Any guidance or suggestions welcome.