"John Smith" wrote in message
...
I bought a condo recently. The heating system is hydronic. Besides
the two inlet and outlet on the top of the gas water heater, there
are two additional inlet and outlet on the side. There is some
water, not much, in the pan under the water heater. I suspect it's
time to replace the water heater. Where can I buy a replacement
heater? I have never seen one like this in a store.

The water may be from something easily replaced, like a pressure relief
valve.

You don't give much description of the heater. Brand? Model? Size?
A plumbing supply will probably have what you want, but a few drops of water
does not meat it must be replaced, cut you should find out where it is
coming from .