Monoflow zone not getting hot on some outlets

[Sallyboy104]

So I did an extension on a house and added about 25 ft of baseboard to a monoflow 1 inch line that had about 50 ft on it already. The monoflow tee outlets were 1/2 inch so they feed 1/2 and come back 1/2. I'm not getting heat from the extension side which I added the 20 ft and from one other baseboard but the other radiators that were there get hot. I tried ups g the pump to a 0010 taco from a 007f3 and nothing. At the boiler the line goes out super hot and comes back super hot. I'm wondering if I changed the monoflow tee to 1 x 3/4 instead of the 1 x 1/×2 if that will help. Any ideas would be greatly appreciated.

 

[Dana]

Are you sure you installed the mono-flow tees in the correct orientation?

 

[Sponsor]

 

[Sallyboy104]

Are you sure you installed the mono-flow tees in the correct orientation?

Yes they were already installed all I did was from one of the outlets i ran about 20 feet and back but like i said there 1/2 on the bull of the tee

 

[Dana]

Is it possible that there is air in your extension, creating a vapor-lock? (Hopefully you installed an air bleeder valve on the downstream side of the radiation on that branch?)

 

[Sallyboy104]

It could be possible but the whole zone goes out super hot and comes back super hot and I reading up on this kind of system and it says when monoflow tees were designed they didn't plan for long runs of baseboard and if u do use baseboard then run short lengths and I'm thinking my problem might be that I have about 40 feet from where it goes out the 1/2 tee and comes back thru a 1/2 tee

 

[Dana]

It's true that the side loops to radiators are usually a lot shorter/lower-head than than an 80' round-trip.