I'm looking to flush my heating pipes, since I recently put a water softener in.
There's a hose connection on the return line leading into the back of the furnace, and a valve below that that isolates that return line from the furnace.
Below that valve, in order, is the cold water inlet (which has a 12psi pressure reducer between it and the water supply), and a circulator.
Here's my plan, which I'd like a sanity check on:
1) Close the valve that isolates the return line from the furnace.2) Run a hose from the drain to the Drainosaur, open the drain valve.
3) Turn all the thermostats way up, so the furnace runs and pushes water through all zones.4) After a few minutes, close the drain valve and open the cutoff valve.
My working theory is that since the return line is cut off, the furnace will draw from the cold water inlet instead, effectively pushing new water through all the pipes.
I don't know how much water is typically drawn during operation, so for all I know, the heating pipes area already full of softened water. But that means they'll also be full of loosened calcium deposits, which is the primary reason I want to flush that water out.
So is my plan sensible? Will the cold water inlet have enough pressure to keep up with the circulator, so air doesn't get in the lines?