Have a gas forced hot water system that uses two circulators.
No zone valves.
a. On the outlet of the furnace, each of the two zones has
an "anti-gravity flow control" valve. These are basically check-valves
to allow flow in only one direction.
These are nice, and have a handle to disable the check function so that
if you are using the furnace during a power outage, you can then have it
work as a pure gravity system.
(as a gravity system, there wouldn't be enough pressure to get passed
the valve, so you have to disable it)
The valve are very old and should be replaced.
The one or two Plumbers I've had over say that they don't come with
these handles to disable their function on them anymore.
I'm sure they probably do, but cannot find any via a Google search.
Can anyone please point me in to a few Links that show them for sale ?
b. And I'm also told that it is illegal
(State, or is it a Federal law ?) to have new, or old, furnaces with the
thermopiles ignition so that you can use it during a power failure.
We get a lot of power failures up here, and it sure is nice to be able
to still use the furnace as a gravity system; it just cycles between the
high and low limits.
Are these replacement thermopiles still available ?
From who ? Link ?