In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
I'm adding a wood boiler to my existing system that is an updated gravity flow system. My current circulator is on the return just before the boiler. The wood boiler manufacturer recommends that I tee in between the existing pump and the boiler return with a additional pump and direct flow to the wood boiler. He also says to tee in another pump at the outlet of the existing boiler between the boiler and radiators (a push-pull arrangement). This pump will pull water from the wood boiler and either put it into the radiators or circulate it backwards through the boiler when the original pump isn't running. The original pump will be controlled by the thermostat. What I can't figure out is how will water ever flow through the existing boiler if the wood fire dies down? The wood boiler is in the garage and the lines are exposed to freezing temperatures (although they are insulated) so I have the keep the 2 new circulators running to keep the lines from freezing.
Another question - will Taco 007 pumps block flow if they are not running? If so I might be able to create a bypass circuit using the pumps to direct and restrict flow.
Thanks in advance.