Heating Help

Oh Where Oh Where Can My SpiroVent Go?

Just finding out I should have installed more air elimination than the Uponor and Caleffi drawings showed. So I am coming to the Wall for help.

I am pumping out of a buffer tank to a 1 inch manifold feeding 4 circuits of radiant. The 1" supply comes off the hot port on the top of the tank and connects to the inlet side of a TACO DT pump. Then each of the four circuits tees upwards to their respective floor loops. There is a boiler drain in the end of the 1 inch header.

Each circuit then returns to a 1 inch return header which then is piped tot he cold port on top of the tank. There is also a boiler drain at the end of the return header.

In addition to the boiler drains at the end of each header, I have ball valves on each circuit. In spite of my best efforts, I still hear air. So I want to install a SprioVent in the header. Uponor school tells me it should be at the zero pressure point in the system, i.e. between the hot port on top of the heater and the circulator pump inlet.

I also read there should be 6 pipe diameters between the air eliminator and elbows. Is that the same rule for the pump inlet?

Do you have an air vent on the buffer tank?

The buffer is a spot where entrained air bubbles would naturally float to the top, and you should exploit this to help you with getting air out of the system. The hot outlet may not be plumbed to the very top of the tank, which would result in an air pocket. Even if it is plumbed to the very top, you lose the opportunity to use the buffer as an air elimination device.

Tank top

Gordon, that's where I put it. The hot port comes off the top then eke back to the wall. I stuck it in the horizontal run a couple ft from the pump inlet. Has been working great so far.

Tank top

I think the dome shaped top helped as well.