Radiant Floor Heat NO Flow

Mike Donner

I have been asked to trouble shoot a no flow situation in two of six circuits in one of the in-floor radiant zones.  The six circuits are connected to a common manifold & circuit 3 & 4 have no flow, the other four are working fine.  Please note this is a new installation & this problem was discovered @ start-up.  I'm thinking maybe there is a kink or a blockage (small stone) in these two circuits.  I was going to suggest disconnecting these circuits from the manifold & hooking up a compressor & blowing air thru the lines, or we could hook up a hose & try to run water thru it @ city pressure.

Any thoughts.

Thanks Mike

NRT_Rob

9 times out of 10

the answer is air.



purge the lines, with the hose. through just the blocked loops, if you can.

Slimpickins

if not air..

If its a new start up, the lines may be crossed at the manifold. Drain down the manifold and if you have compression fittings on the radiant tubes, disconnect but the supply and return on the tubes with no flow, blow on the tubes and make sure they are hooked up correctly. I've seen a supply tube with its return hooked up to the supply as well. Heck, I think I've done it myself once.

Mike Donner

Problem Fixed

It turned out to be crossed lines, problem fixed.

Thanks

NRT_Rob

nice one

Slimpickins!

Slimpickins

aww shucks

Well my answer came from experience because I did it early in my career when I hooked up tubes to a manifold. I'm still learning things and hanging out on the wall keeps that process ongoing.