Pre-Purge

Jim_46

This is going to be hard to keep short but here goes. Boiler with cast iron and runtal steel rads. Yesterday I drained the system and made my connections for the new loop that will be going to a radiant floor. I added a tee at the top of the boiler at the supply where there was an elbow and started my new loop with a shutoff then a Supervent air eliminator then another shutoff (for cleaning the eliminator)I also teed into the return side of my original loop with a one way check and a shutoff. So these two connections (supply and return) are shutoff from the main system while I do the rest of the radiant floor hookups. So with them isolated I then refilled my original radiator loop and it is all up and running and I can work away at the new loop. The problem of course is I now have air in the main loop gurgling and surging through the pipes and I can't get it all with just the rad vents. I can't do a simple purge by lifting the lever on the cold water combination feed valve because it feeds right into the return side by the drain valve so as soon as I open the drain the new water just escapes from there. So here is want I intend to do. Since I already have access to the new unfinished loop just about 18" from the teed supply line I am going to add a Purge/Fill valve for a garden hose connection and just temporarily cap the one side of the valve until I continue the new piping. Then I can purge right into the supply side of my old loop and open the drain side till all the air is out. I would have to run the garden hose through a screw on pressure gauge to make sure I keep the garden hose at about 15 psi . I would also temporarily close the valve to my old bladderless expansion tank so I don't fill it anymore. I need to get rid of this air before I go any further with the new loop. Once The new loop is finished I will also be filling and purging that from the Rehau manifold. Other than the fact my message is too long...what do you think??

Weezbo

Jim, sweat two 1/4 turn ball valves on the new \"Leads\"

one on the supply one on the return sweat two no kink hose bibs on each valve take a washingmachine hose and connect one end to each no kink,open the ball valves and the spiro vent will do the rest...i dont quite get how your feed water system is lashed to the system...if you cannot add water (isolated system) then cool the boiler down to 70 then add water into one of the new purge valves (no kinks) and bleed the other side off into a bucket.when there are no more bubbles close off the return side from the field then run the pressure up to like twenty psi close the ball valve...hook up the washing machine hose and re fire the boiler to like 100 degrees and shut it off a few 5 6 mins then crank it back up again to its normal operating temps...the pressures going to go up a bit as thishappens,the recircpump will run the water around the entire system the washing machine hose will act like a By pass and the spiro vent will eliminate micro bubles of air and the pressure will dwindle down as the entrained air is released...