Can you use the circ pump to fill system???

[bloodvette]

According to this pumping drawing I drew up, Is it possible to fill my infloor radiant system by using the circulation pump? I noticed of all the plumbing layout pictures I've seen, people usually use a seperate pump to fill the system, but I don't see why you can't just use the one you already have plumbed in...

If you open the "Fill" and the "Fill Return" valves, and you close the #1 Pump isolation" valve, then once you have the pump primed (gravity to prime), wouldn't it do a perfect job of filling the system, the other question is, will it be able to pump the system up to 20psi?? (close the "Fill Return" valve and keep pumping up pressure to 20psi). I know the circ pump is a certrifigal pump not a positive displacement pump which would be ideal for getting the pressure in the lines...

Any opinions???

 

[metaldad]

no. you should be able to fill adequately by gravity, and then with a city pressure hose., with check valve,(i assume a glycol system). cartridge type pumps require fluid thru them for cooling. coupled pumps may damage seal.
once you're generally filled and properly vented, you should be at pressure. (20# is kinda high for a radiant, unless there is a higher than usual head)

 

[DZL JIM]

When I did mine, I mixed the glycol and water in 5 gal buckets, then used an old sump pump with double female ended hose to fill the system.
Pretty simple, actually, I don't see how using the circ pump wouldl
work as well.
Good luck.