Diverter-Tee System Question

HBW

Did you say that you have zone valves on the 3/4 branchs to each area? Are they 2-way or 3-way?

Adam E

Diverter-Tee System Question

I've got a 3 zone Diverter-Tee system with Burnhan cast-iron baseboards and I've got a few questions as to why I've got some cold radiators.

There's four bedrooms and 2 baths on the zone in question. One the main 1" circuit the first 4 tees are all standard tees feeding the first 4 rooms (2 bedrooms & 2 baths). Then there's 3 return diverter-tees in a row, then it's feed,return, feed, then two returns.

The return diverter-tee for the first room is the last of the 12 tees on the circuit. This is a VERY hot room. The rest of the rooms generally get progressively colder. The last 2 rooms are mostly ice cold.

The diverter-tees don't look like B&G monoflos. There's no name on them. They look a lot like standard tees only with a restriction on the one side (a couple of them have a smaller restriction on the opposite side). They look like someone took a wire loop to them and pulled it real tight.

Could these be B&G? Taco? Generic?

Would replacing the diveter-tees with real Monoflos help? How about moving that last return to the second in line?

Adam E

Diverter-Tee System Question

I've got a 3 zone diverter-tee system with Burnhan cast-iron baseboards and I've got a few questions as to why I've got some cold radiators.

There's four bedrooms and 2 baths on the zone in question. One the main 1" circuit the first 4 tees are all standard tees feeding the first 4 rooms (2 bedrooms & 2 baths). Then there's 3 return diverter-tees in a row, then it's feed,return, feed, then two returns.

The return diverter-tee for the first room is the last of the 12 tees on the circuit. This is a VERY hot room. The rest of the rooms generally get progressively colder. The last 2 rooms are mostly ice cold.

The diverter-tees don't look like B&G monoflos. There's no name on them. They look a lot like standard tees only with a restriction on the one side (a couple of them have a smaller restriction on the opposite side). They look like someone took a wire loop to them and pulled it real tight.

Could these be B&G? Taco? Generic?

Would replacing the diveter-tees with real Monoflos help? How about moving that last return to the second in line?

Adam E

Diverter-Tee System Question

I've got a 3 zone diverter-tee system with Burnhan cast-iron baseboards and I've got a few questions as to why I've got some cold radiators.

There's four bedrooms and 2 baths on the zone in question. One the main 1" circuit the first 4 tees are all standard tees feeding the first 4 rooms (2 bedrooms & 2 baths). Then there's 3 return diverter-tees in a row, then it's feed,return, feed, then two returns. Three feet before the second tee the main is ice cold. All feeds are standard tees and all returns are diverter.

The return diverter-tee for the first room is the last of the 12 tees on the circuit. This is a VERY hot room. The rest of the rooms generally get progressively colder. The last 2 rooms are mostly ice cold.

The diverter-tees don't look like B&G monoflos. There's no name on them. They look a lot like standard tees only with a restriction on the one side (a couple of them have a smaller restriction on the opposite side). They look like someone took a wire loop to them and pulled it real tight.

Could these be B&G? Taco? Generic?

Would replacing the diveter-tees with real Monoflos help? How about taking the return tee for that first room and putting it after that room's feed?

The boiler has to run a long time (more than 5 minutes) to get warm on the end of the circuit (it never really gets hot).

Should I split the zone? New circulator?

Thanks for reading this far!

Adam E

Diverter-Tee System Question

I've got a 3 zone diverter-tee system with Burnhan cast-iron baseboards and I've got a few questions as to why I've got some cold radiators.

There's four bedrooms and 2 baths on the zone in question. One the main 1" circuit the first 4 tees are all standard tees feeding the first 4 rooms (2 bedrooms & 2 baths). Then there's 3 return diverter-tees in a row, then it's feed,return, feed, then two returns. Three feet before the second tee the main is ice cold. All feeds are standard tees and all returns are diverter.

The return diverter-tee for the first room is the last of the 12 tees on the circuit. This is a VERY hot room. The rest of the rooms generally get progressively colder. The last 2 rooms are mostly ice cold.

The diverter-tees don't look like B&G monoflos. There's no name on them. They look a lot like standard tees only with a restriction on the one side (a couple of them have a smaller restriction on the opposite side). They look like someone took a wire loop to them and pulled it real tight.

Could these be B&G? Taco? Generic?

Would replacing the diveter-tees with real Monoflos help? How about taking the return tee for that first room and putting it after that room's feed?

The boiler has to run a long time (more than 5 minutes) to get warm on the end of the circuit (it never really gets hot).

Should I split the zone? New circulator?

Thanks for reading this far!

P.S. All three zones are necked down to 3/4" at the zone valves and at the returns for the drain and shutoffs. Not sure if this is a problem.

Thanks again.

Adam

Adam E

Diverter-Tee System Question

I've got a 3 zone diverter-tee system with Burnham cast-iron baseboards in my rancher and I've got a few questions as to why I've got some cold radiators.

There's four bedrooms and 2 baths on the zone in question. One the main 1" circuit the first 4 tees are all standard tees feeding the first 4 rooms (2 bedrooms & 2 baths). Then there's 3 return diverter-tees in a row, then it's feed, return, feed, then two returns. All feeds are standard tees and all returns are diverter.

The return tee for the first room is the last of the 12 tees on the circuit. This is a VERY hot room. The rest of the rooms generally get progressively colder. The last 2 rooms are mostly ice cold.

The diverter-tees don't look like B&G monoflos. There's no name on them. They look a lot like standard tees only with a restriction on the one side (a couple of them have a smaller restriction on the opposite side). They look like someone took a wire loop to them and pulled it real tight. I assume they're original 1957 parts.

Could these be B&G? Taco? Generic?

Would replacing the diveter-tees with real Monoflos help? How about taking the return tee for that first room and putting just after it own feed?

The boiler has to run a long time (more than 5 minutes) to get warm on the end of the circuit (it never really gets hot).

Should I split the zone? New circulator? Any recommended reading to help me?

Thanks for reading this far!

P.S. All three zones are necked down to 3/4" at the zone valves and at the returns for the drain and shutoffs. Not sure if this is a problem.

Thanks again.

Adam

John Ruhnke1

Sounds like a delta tee problem......

The problem is most likely caused by the delta tee being too large. Delta tee is the differance in temperature from the feed to the return. After every radiator, the temperature drops because that radiator used some of the heat. If the return loop at the boiler is not hot enough that means there isn't enough BTU's in the water to heat every thing up. One gallon of water per minute equals 10,000 btu's. One thing you can do is to change the pump and increase the gallons per minute thus increasing the btu's and decreasing the delta tee. To find the proper pump you need to look up the head and flow rates on a pump curve chart. Your local supply house should have the pump curves, if not call Taco they will be glad to help you properly size the pump. If the main is to long or small you may not beable to get enough btu's out of it even if you pick a bigger pump. In that case you will have to increase the size of the main.

JR

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Steamhead

Could also be a flow problem

since you only have one circulator and the piping is reduced from 1-inch to 3/4-inch. The flow is probably inadequate to begin with and it changes depending on how many zone valves are open.

If that were my job, I'd ditch the zone valves and use 3 circulators- 1 for each loop, each sized to the loop it serves. I'd also run all the piping full size back to the (properly sized) supply and return headers, and Pump Away.

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HBW

Steamhead

You could use the zones valves as long as they were 3-way diverting type.

Steamhead

Yes, that would work

if they were sized correctly. But these are 3/4" ZVs on 1" loops, which tells me theyre restricting the flow in the loops. I really think this is a flow problem, and dedicated circs would insure each loop gets its proper flow.

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HBW

PSI DROP

If the zone valves are 1-way and when they close off, excessive pressure drop is created (without the branch bypass) due to the monoflows. I have a job with 10 3/4"-3-way zone valves, 1-pump, a mixture of baseboard and runtal radiators. It works very well as long as you size everything right.

HBW

Zone Valves

1-1/4 main loop, (x1) Pump, (x10)Zones, 3/4 branches, 3/4 3-way zones valves. Works great but you have to size everything correctly.

keith

Is balancing

the system a option? Check the balancing valves, they may need adjustment. Throttle rads untill they heat evenly. Did someone change the pump to cause this flow problem? Has this been a problem as long as you have been in the house?

Adam E

Is balancing an option?

I thought that in monoflo systems it was recommended that all valves be open. Mostly for the same reason that you don't want to cap off an old branch.

Adam E

Zone Valves

No, I have 3 zones, each being a 1" curcuit. At the boiler, I have 3 zone valves (in line Honeywells). For these valves, the piping is reduced to 3/4" for about 12" then back to 1".

On the return side the 1" is reduced to 3/4" for the shutoffs and drains, then it's back to 1" into the boiler.

Adam E

Delta Tee Problem

When figuring out the head, do measure the length of the 1" mains for all three zones? Since there's not priority zoning, I would assume that's a yes?

The quick formula I found at B&Gs site doesn't mention main pipe size. Does this not matter?

Right now I have a Taco 007 pulling all three zones.

Thanks.

Adam E

Delta Tee Problem

Oops

Adam E

Should I assume

that since it wasn't mentioned in any responses, that the fact that there's four standard tees feeding four rooms before there's any monoflo returns shouldn't be a problem?

Thanks.

Joe_5

A thought

Adam, Has this system ever worked properly? I'm asking because it sounds like it's an older system and the old monoflo type systems I've seen in my area all work well until somebody tries to add on or modify it. Usually us newer guys, at least until we learn the older ways, will just mess up a monoflo system. When I read your original post, your statement of "the return tee for the first room is the last tee of the 12 tees" doesn't seem right to me. That means that when the water goes into that first tee, most of it stays in the main pipe, say 10 gpm while 2 gpm goes up to the first room zone, you won't get that 2 gpm's worth of water back again until the end of the main, after all of the other tees. This will reduce the available water to all of the zones in between the 1st zone's tees. If the piping is this way on the first zone, it's a good bet the other zones may have mistakes too. Sounds like somebody installed zone valves to correct a piping mistake. Does anybody agree? Disagree? Joe

Adam E

A thought

It's never worked great. It's hard to say if it's any worse now than when I bought the place six years ago. It seems like it, but it's probably just that it's really starting to aggravate me. Plus, my 4-year-old daughter can complain now.

The boiler is an 8 year old Columbia EM-125 and I assume the rest of the system is original 1957.

Yes, it's true that the first room's return is the last of the 12 tees on the main. Also, the first 4 rooms are fed before there's ANY returns! I thought this may be a major wrinkle, but up until now nobody mentioned it so I figured I shouldn't worry about it.

Thanks.

Mike Kraft

Adam........

Your 1st post quoted"There's four bedrooms and 2 baths on the zone in question. One the main 1" circuit the first 4 tees are all standard tees feeding the first 4 rooms (2 bedrooms & 2 baths). Then there's 3 return diverter-tees in a row, then it's feed, return, feed, then two returns. All feeds are standard tees and all returns are diverter."

That sure sounds and is wrong!If you have 4 standard tees branching to the feed of each emitter and then those four tees followed by 4 diverter type tees and picking up the returns then somebody made a boo-boo.

What you want is this.......Lets say bed #! has 8' of iron BB...ok.....the first fitting at the supply branch(if upfeeding)should be a regular branch tee.Then 8' downstream of your main should be a diverter tee accepting the return from your same iron emitter.This needs to follow suit from room to room.

To determine wether you need to change the ZV's or not because of a flow issue can be done witha heat loss and some math.

Top left of this page ........do yourself a favor!.......click on "Heating Q&A" read the chapter on diverter tee heating.

Let us know the results!

cheese

Joe_5

your house!

Adam, what you have is a great situation. Every night when you get home, your wife and your little one will remind you of how they're cold and why haven't you figured this %$#@% boiler thing out! Sounds like I'm crazy right? I think the best education is one with real world experience. You have yourself a project that won't make you any money but will surely teach you a lot! Other guys might disagree but I'd rather make my mistakes on my own stuff. Too much guilt for me if I screw up other people's stuff. Go with what The Cheese said and you'll eventually figure it out. Start buying Dan's books and that'll help too! Good luck! Joe

Julie

Re: Diverter tees

Hi Adam,

I usually just lurk here and don't post. However, I have designed heating systems using B&G and Taco diverter tees/monoflow fittings, and I think I know what is wrong with your system.

Because the return diverter tee for the first baseboard is located at the end of the zone, the pressure drop of all of the fittings between the feeder tee and the return tee (including *all* of the other diverter tees) is causing too much water to go into through first baseboard. It is very important when laying out diverter tee systems to put the return diverter tee in the main immediately after the feeder tee. If you intermingle the feeders and returns, the calculations to figure out how much water is going where become quite complex.

My recommendation would be to repipe, but perhaps that is not practical...

Julie