Branch Supply Single Return Baseboard Heating Questions

jthein

Hi Everyone,

I have been a long time lurker here but this is my first question. I have a smaller ranch home with a single zone baseboard heating system. Water leaves the boiler and splits into two branches, one which runs along the front of the house and one which runs towards the end of the house. These supplies are 3/4" copper. Both of these supplies get to the end of the house and enter a wye and move up to 1" and return back to the boiler. The pump is on the return side of the boiler.

I would like to remove the wye and tuck pex up into the joists for the return. I am finishing my basement and don't want to box out around the pipe.

My plan is to get a 3/4" 3/4" 1" pex tee and remove the wye and run the pex in the joists. I am going to get the oxygen barrier piping. Would i run into any issue if i replace the wye with a tee? Do i need a monoflow tee in this instance?

I appreciate any insight that you can give me. Thank you.

Jamie Hall

No problem. Run the two branch lines into the opposite ends of the cross of the T and take the return out of the leg. That way they will stay more or less as balanced as they are now.

EBEBRATT-Ed

You may run into a balancing issue with a tee. The circuit going into the brach of the tee will probably get less flow. That is why the Y is preferred.

Can you leave the "Y" and run 1" pex back to the boiler?

Or use 2 3/4"balancing valves on the inlet to the tee

Or run each circuit back to the boiler separately in 3/4 pex. Put a 1x3/4x3/4 tee in the return at the boiler and put two balancing valves on the new tee as you're going to have to cut the old pipe out anyhow.

The last option is what I would do then you would only have to buy 3/4" pex which is much easier to work with.

jthein

https://forum.heatinghelp.com/discussion/comment/1809265#Comment_1809265

I like your comment. I was thinking of doing two 3/4” pipes back to the boiler and was wondering if it would work. 

As for the tee. Both supplies would go into the tee evenly and return to the boiler. 

As for balancing valves, what would I need. Do they ever go bad?

Jamie Hall

"You may run into a balancing issue with a tee. The circuit going into the brach of the tee will probably get less flow. That is why the Y is preferred."

That's not like you, @EBEBRATT-Ed !

Which is why the output goes OUT of the leg or branch, and both loop returns go INTO the opposite ends of the crossbar. That way the flow is balanced. If you did put one loop into the branch and the other into one end of the crossbar with the return to the boiler out the other end of the crossbar, you would have horrendous balancing problems.

Balancing valves would, however, be a good idea. You can use an ordinary ball valve, although they are a bit imprecise. Or globe valves, though they have much more head loss. There are special balancing valves made for fine tuning. I doubt that you need that level of control. They are a set it and forget it device.