I'm not an expert on any of this, but we have a very
similar situation. There's a chimney that's now taking
only the water heater vent and there's a dead chimney.
I hadn't heard the idea that the chimney might be too
big for the vent. It seems to work fine. But we never
had condensation, either. I find it hard to imagine that
venting just the water heater through the chimney might
be a problem. It's not a heck of a lot of heat produced.
Mostly I'm just relieved that the furnace now vents outside
with PVC. The house was built in 1835. It made me nervous
to have the furnace venting through such an old chimney,
which is partially buried in walls with no way to check for
leaks or parge it.
We also have a dead chimney that I think had been used in
the 1800s for wood stoves. The living room and upstairs
bedroom both had a vent hole. It's been long dead now
and was cut off under the roof, in the attic. When I
remodelled the attic I capped it with concrete, mainly
for two reasons: To prevent field mice possibly coming
up to the attic from the cellar, and for safety, in case
someone ever decides to put in a wood stove without
checking the furnace first. (They'll get an awfully lot
of smoke but at least they won't set the roof on fire. :)
In your case I don't imagine there'd be any reason to
do anything about the chimney. It would take some work
to dismantle it and reroof. As long as the bricks aren't
falling, who cares?
|I am putting my reply here rather than individually.
| My house was built in 1898
| I have been here for about 35 years and there is always something to do.
| Since this is going to cost a few buck I guess I will only get part of
| it done this year.
| If I get a high efficiency furnace and an electric gas heater and no
| longer need a chimney at all, what's the best thing to do then?
| Should it just be insulated and capped?
| To remove it entirely would be expensive.
| If it does get removed I'll be saving that job for when the entire roof
| needs to be replaced...possibly in five years.