heating upstairs zone works, downstairs doesn't - New piping

[Philtrap]

Folks,

I just fired up my TT-110. The upstairs zone works fine. The downstairs (the one to the left) doesn't. The pipe above the valve hardly gets hot. Even when the circulator pump is on and the the second zone is closed. The Diff Bypass valve is set properly and water is not flowing back thru it. Something isn't right. I check and the zone valve is working. I even tried it manually. The flow goes up.

I'm thinking the down stairs tee may be too close to the elbow to the left. I've see the rule of 12d. I can fix this, but do you think that's the problem. I don't want to do that work if it's not the problem. The zone valves are 4d apart.

Any input would be greatly appreciated.

Sorry about the photo being sideways. I tried to fix it with no luck. Up is to the left

 

[Jadnashua]

It's more common to have air in the higher level, but it doesn't take much to block flow through a loop...first thing I'd do is try to purge air from the system again.

 

[Sponsor]

 

[Philtrap]

Thanks jadnashua!! I re-purged again and one large burp and now all is fine now.

It's more common to have air in the higher level, but it doesn't take much to block flow through a loop...first thing I'd do is try to purge air from the system again.