mono flow problems

adambuild

Are you certain all the air is out? We had a job where we just installed a new Ultra and one rad was cold. There must have been an air pocket that wouldn't purge. I boosted the fill pressure to 25# for a few days and problem solved! The oxygen went back into solution.

schiller

mono problems

after installing a new burnham boiler our customer is stating that a rad. in the basement is not heating.
Can the pump be on the supply side (after the exp. tank) or should it be on the return side.

Michael Keating

mono flow

I recall a problem like that and we had to install another monoflow tee on the side that did not have one. The water does not like to go in a downward direction so it really needs to be forced. Monoflo on both supply and return. This is of coures providing theat the air is eliminated

Brad White_8

Pump should

always be on the supply side, that is, pumping away from the expansion tank. That is one part.

The other is, with a monoflow system, if a radiator is downfed from a main above, it requires a monoflow tee on both supply and return (push and pull). This is to overcome the natural bouyancy of hotter water. (Proof that thermal dip traps work!) If you have the conventional B&G fittings, the red rings face each other. You also want to make sure that there is sufficient main between them, not a short coupling. Give the water another reason to "leave the highway take the shore road".

I have to assume that the main is sufficiently sized for the entire house. For example, and God Forbid you used a 3/4 inch main with 3/4 x 1/2 monoflow tees... the manufacturer recommends only one in such a branch. Chances are you do not have this condition, but thought I should say something...

In my own house, I had a similar problem, a non-heating basement radiator, for years. Lived with it; did not use the basement much. Years later when I removed the mains it was apparent why: The tees were installed backwards since 1963... just another thought to check.

Hope this helps.

Uni R

Maybe...

This may be a case where you just need to let the circulating water cool down enough that there isn't a big difference in bouyancy between it and the cooler water in the basement branch. Then once the water starts flowing through heat everything back up.