Hello,

I own a house that contains a rented apartment on the upper floor. The
entire house was centrally heated via an oil furnace and hot water
radiators.



A few years ago we had a contractor install electric baseboard heating
upstairs so the tenant could control and pay for their own heating. As a
result the old radiators were removed and the water pipes leading up to the
radiators were cut just above the floor level and capped since they were not
required anymore in the upstairs lodging.



It was recently pointed out that the hardwood floor is discoloring (as if
rotting) in the area around the capped pipes where the old radiators were.
I have not noticed any condensation around the capped pipe and no leak is
evident. This is evident in more than one room so it seems related to the
capped water pipe. What could be causing this? Could it be condensation
from the pipe, although it isn't evident when I inspect it.

Any suggestions welcome.

Basil