Radiant Heat Problem

Rich_3

A new zone of radiant heat with 5 loops (each 100 feet). It will not work with the pump on, however, when you open the flow-check it will gravity around. Help is appreciated. Replaced pump and bled air. Could it be the return piping?


Respectfully,
rich
HVAC contractor--over-tired and cannot see the forest through the trees.

Tony_8

seems

if it flows gravity style the piping shouldn't be suspect. Does it circ with the pump with the flow-check open ? If you screw the flow check stem down tight some will restrict the travel of the weight, thus restricting the flow. Is the pump flow in the proper direction ?

Dave H_2

Piping and heat source

Rich-

What is the heat source and is there a mixing valve piped into the system?

If you are using a mixing valve, remember that a mixing valve separates the system. Meaning that if a mixing valve is utilized, the circulator must be placed on the supply side feeding the manifold AFTER the mixing valve.

Take a look at the following page

Cosmo_2

Lets take a look

Take some pics of the job and we can better help. We are all brothers here and no shame amoung us. It could be that a circ may not be in the right place as noted above, or something different. I went out to troubleshoot a job that the original contractor could not get to work and the only problem was that the zone circ for the panel in question was oversized and the water was moving so fast that the temp drop between supply and return from the panel was only 3 degrees! Lets figure it out...


Cosmo

Mark Eatherton1

Sometimes...

the obvious escapes us. Are you positive the circulator is attempting to flow in the correct direction? With 100 footers that fluid should be SCREAMIN' through the pipes.

Trust me, I've installed a pump or two backwards...

ME