Help! Split loop HWBB system, only one side heats

Dick Charland

Check to see where the splits tie back in to the return, there should be balancing valves (depending on manufacturer may have handle or screw slot for adjustment) that allow you to balance the flow through the loops. Sounds like you have a purge setup, shut off the valve to the side that is heating and purge out the other side of the loop. After, feel both return pipes to see which side returns the quickest and then close the repective valve in small increments until you get both sides heating at about the same time.

[Deleted User]

What do I do?

I am stumped! After searching the internet and looking through all material I can find, I can't seem to figure this out. I have an oil furnace with 3 zones -- upstairs, basement, and hot water tank. The upstairs is split into 2 loops, as far as I can tell. I have two 3/4" pipes going out from the top of the furnace, and one 1" pipe feeding into the circulator, which feeds into the bottom of the furnace.

Only half of this split loop seems to be heating up. I am assuming that there is air in the other half, because if it was a circulator or furnace problem, it would affect the whole loop or the whole system, right?

Anyway, the problem is that I can't find where the air vents are to bleed out the half loop. I know they must be there, because the system had to have been air-bled when it was installed, right?

And of course, the half that is not working is the half that supplies heat to the kids' rooms. So they have been sleeping with us!

Please help! Is there a place that I might not be looking, or is it common for the system to not have the proper vents in place? Do I need to cut a couple of vents into the line? And if so, where should they go?

Thank you for your time.
Mike.

bigugh_4

Boy oh Boy

> I am stumped! After searching the internet and

> looking through all material I can find, I can't

> seem to figure this out. I have an oil furnace

> with 3 zones -- upstairs, basement, and hot water

> tank. The upstairs is split into 2 loops, as far

> as I can tell. I have two 3/4" pipes going out

> from the top of the furnace, and one 1" pipe

> feeding into the circulator, which feeds into the

> bottom of the furnace.

>

> Only half of this split

> loop seems to be heating up. I am assuming that

> there is air in the other half, because if it was

> a circulator or furnace problem, it would affect

> the whole loop or the whole system,

> right?

>

> Anyway, the problem is that I can't

> find where the air vents are to bleed out the

> half loop. I know they must be there, because

> the system had to have been air-bled when it was

> installed, right?

>

> And of course, the half that

> is not working is the half that supplies heat to

> the kids' rooms. So they have been sleeping with

> us!

>

> Please help! Is there a place that I

> might not be looking, or is it common for the

> system to not have the proper vents in place? Do

> I need to cut a couple of vents into the line?

> And if so, where should they go?

>

> Thank you for

> your time. Mike.

bigugh_4

Boy oh Boy !

split loops are a nightmare! or can be. 1. the pump? is it really working up to its potential. That is could the impeller be worn away? 2. air, and your on that idea. It may have been flow purged like so much is done today. Valving off section and running lots of water through till it is clear of air. 3. balance problems. Water will always go the easiest way. conceled balance valves may be upset. With these ideas in mind re-look at your set up. and think where would and why would I (if water)go?

Weezbo

there may be a lock in a riser....

not far from the junction of the split loop.a simple coin vent on a riser or a coin vent off the top of a pipe run from a say 3/4X1/2 T would likely solve some of the problem.. with the old butterfly valve it was sorta spendy now we have 1/4 turn ball valves that can be low profile with a key type handle..that might be good to have along side of a T with a coin vent off the top of the run,that way you can block flow from one direction at least.

Scott04

Split loops are simple...if you know what your doing! If you knew, you wouldn't be here getting questionable advice! Call your service company and get it done right!

Weezbo

that brings up another thought.......

ask the kids if they may have been playiing plumber *~/:)

nimble little hands may have twisted the balancing valve or globe or ball valve to a shut position ......eh?