Need suggestions...diverter tee no heat

Timco

No heat to two out of four radiators, top floor. Diverter tee loop in basement. The take offs to the top floor rads come from the DT fitting and to an outside wall, then up to top floor. 10' basement ceiling, 10' main floor ceiling. Pump is 26-99, set on High. As if this setup wasn't bad enough, two of the rads were moved across the room from where they sat originally. DT loop is 2", and take offs are 1" that reduce somewhere to 3/4 at the rads. Issue is that I get great heat around the loop in the basement but no heat through 2-3 of the rads. Sometimes it flies, sometimes not. The water in the supply & return along the outside wall is super cold. Even with a series 100 B&G, I just can't get the water to divert. The loop in the basement just heats faster with a larger pump. Sorry, no pics of near boiler piping. Pumping away from x-tank, no air. Main floor and basement run great. CIBB main floor in 2-pipe, CFBB basement, one loop. Am I going to need a small pump on each take-off to get reliable flow?



Thanks,  Tim

Robert_25

Gravity

Are you sure that isn't an old gravity system? I am wondering if a low-flow pump would help. Are there any valves upstream of the circulator that you could use to slow down the flow?

Robert_25

Gravity

Are you sure that isn't an old gravity system? I am wondering if a low-flow pump would help. Are there any valves upstream of the circulator that you could use to slow down the flow?

Mark Eatherton

That's not a monoflo tee Tim.....

That is a gravity tee. It depends upon the density of water to cause movement, not velocity like true MF tees do.



That particular tee has little to no pressure drop between the branches, and will not induce flow into the secondary side of the branches, other than what gravity can generate.



Also, with it being gravity, it can't withstand even a LITTLE air binding, because there is nothing but gravity to move flow. Purging with any traps, i.e. going under beams getting from one side of a room to the other, will definitely cause air binding, and is difficult to purge, if possible at all.



Best of luck.



ME

Charlie from wmass

since you have the Grundfos try it on low

speed and see if it it helps. Other wise start checking out taco or wilo small pumps Or simply repipe the loop as a mono flo with a smaller loop pipe. or home run them to a manifold and ninstal trvs with a variable speed pump.

Timco

thanks!

There are no other valves besides the purge stations I installed. I will try this on the lowest setting, smallest pump tomorrow. If this does not work, I will price out tiny pumps to move the water up manually. The take-off points are all up in a finished ceiling. I guess with that much pump on the main loop, there is no chance of gravity doing it's job. No other options here because of a finished ceiling in the basement. This one is a challenge but I am determined to make this fly....



Thanks again,   Tim

croydoncorgi

Confused Brit (again)

Someone explain ( to someone who's NEVER seen a pipe setup like the illustration) what it's supposed to do and how?!!

Thanks.



(All this one-pipe technology is virtually unknown here in UK.)

Mark Eatherton

The concept is EXTREMELY rare...

Most of them were done at the turn of the century. The late 1800 to early 1900's specifically.



Steam systems were on their way out due to safety issues. The inventor of the one pipe hot water gravity system was trying to compete with the one pipe steam systems that were the predecessor to hot water heating, and were in direct competition with each other during that point in time. If you click on the picture, you will see arrows. The hot water (less dense) rides along the top of the pipe. It rises upwards, via gravity, and goes through the cast iron radiator, and gives up its heat, and that return water is more dense, and wants to fall back down to the main. The left hand side of the tee has a tunnel that runs along the outer edge of the cast fitting, and it introduces the cooler water along the bottom of the pipe. The pipe can flow counter current, and I've seen some that ran parallel (hot and cold running in the same direction. In most cases, the water piping starts out low near the boiler, and works its way around a perimeter circuit, and once it has serviced the last radiator, that is the apex of the piping, and everything flows in a downward fashion back to the heat source, which here in Denver were originally solid fuel (coal or wood or both) and eventually converted to city gas, then natural gas. In situations where the boiler is being replaced, it really doesn't require a pump of significant capacity (head or GPM) because it was designed to work with gravity.



The tee that Timco shows is a Phelps One Main Tee. There were others on the market, including a fitting called the O-S fitting, which was invented by gent name Oliver Schlemmer, hence the name O-S Fitting.



Here is a link to information that Dan has written on gravity hot water systems. Most were 2 pipe, but some were 1 pipe.



http://www.heatinghelp.com/article/17/Hot-Water/72/Gravity-Hot-Water-Heating



Cheers!



ME