Noisy Varivalve on cool down?

Steve Nichols

I have a one pipe steam convector system in my home. I'm using several straight angle Varivalves due to tight clearances with the convectors and the need to balance the house system. They vent really well, but when system "cools down", radiators equipped with the Varivalves pop open and a huge rush of air can be heard for about 5 seconds. It sounds similar to a pop off valve on an air compressor. I am assuming this is vacuum being produced as the mains cool down when steam is not being produced. These suckers are loud enough to have woken me up when they go off in another room. Are they typically this loud? I'm running between .5 to 1.5 psi on the Pressuretrol.

Thanks, (the steam newbie)

Jack_49

I had the same problem, this is what I did to solve it. I installed a vacuum relief valve right after the main vent. I picked it up at home depot. it is 1/2 inch threaded. It is brass with a black plastic cap. You can find them in the section that sells baseboard heating. It has been in my system for 4 years now with no problems and is rated at I believe 250 degrees so you shouldn't have a problem unless you run at extremely high pressures. Hope this helps.
-Jack

Steve Nichols

thanks

Thanks Jack. I think I know what kind of valve you're talking about. I appreciate the help.