Problem with 007w /flo chk

tom mahon

Anyone else having air lock problems with 00's with integral flo check valves.I now know drain valve has to be on discharge side of pump---but what else should should I look for ?

David Van Wickler

good purge and pump away

I have heard of some difficulty getting air out - The question is are you purging sufficiently to get the air out on the first purge? The pump placement makes the difference too. By pumping away typically the fluid is drawn through the air seperator or air scoop (if piped correctly) most of the air will be vented. If the pump is on the return, the drop in system pressure may be contributing to the air binding as well as insufficient purging.

This could also be compounded in thermostatic mixing valve piping arrangements where the mixing valve pressure drop causes increased low pressure at the inlet side of the pump. Always purge thermostatic mixing valve with a cold boiler and the valve set to the hottest setting. OR install a 1/2" by-pass around the mixing valve for purging hot. Just remember to take the handle off the by-pass valve and chuck it into the garbage.

DVW