heat zone always pulls heat


Old 01-13-03, 10:36 AM
Visiting Guest
Posts: n/a
heat zone always pulls heat

I have a brand new, forced hot water boiler with 5 zones.
It was in stalled in May, and not truly tested until the weather has gotten colder. I live in NE Mass.
One zone always seems to be getting heat. Whenever another zone called for heat, it fed that zone, plus zone 4 (AKA problem zone) Zone 4 would heat to 80+ degrees. I had the installation guy come back, and he told me that it was a plumbing problem - but when I trace all the pipes in my crawlspace - it's not the issue - neither was it an issue before the boiler was installed. He electrically disconnected the pump, but zone 4 still gets heat - although not like before - only 60-65 degrees - aqlthough technically it's no longer connected. I had a new thermostat installed, and it was of no help. I think it's either a flow check stuck open or the pump not properly working.
Installation man is of little help
Sponsored Links
Old 01-13-03, 11:35 AM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 10,128
Received 35 Votes on 33 Posts
mcd-runner :

How exactly and byy what are the zones controlled.

If you would read the anouncement at the top of this forum you will find more questions for what would be helpfull to know.
Old 01-13-03, 11:35 AM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 10,128
Received 35 Votes on 33 Posts
mcd-runner :

How exactly and by what are the zones controlled.

If you would read the anouncement at the top of this forum you will find more questions for what would be helpfull to know.
Old 01-13-03, 11:57 AM
Visiting Guest
Posts: n/a
response to Greg

Sorry about that - each individual zone has it's own thermostat that is linked to a power box of sorts. That than is linked to a pump on the boiler. The way it was explained to me is that the pump calls the water through the pipes back into the boiler, where it's heated. It's only a problem with this one zone that I think always seems to pull the heat.

1. Where you live and temperatures you usually experience. I live on the ocean in northeastern Mass.
2. House style and construction details. It's a pretty open floor plan, built in 1988. Raised on cinderblocks w/ an enclosed basement. House is all wooden construction
3. Make model and age of equipment related to the problem. Do not know the model #, but it's brand new
4. Fuel type. natural gas
5. Water temperature and pressures of boiler systems. Not positive on the temp, but pressure is about 18 psi.
6. Thermostat type. Was the older style circluar honeywell, but replaced to a digital honeywell (which is currently not connected, and zone still pulls heat.)
7. Any thing else that would be usefull. No detail to small.
Old 01-13-03, 01:50 PM
Visiting Guest
Posts: n/a
Each zone has its' own circulating pump? If so then each zone needs a Bell & Gossett Flo-Control Valve. They are designed to prevent water from flowing into a zone when it is not calling for heat. Check them out at www.bellgossett.com

What follows is a Q & A section from the website. Not all of the information applies to your situation.

Q: What does a B&GFlo-Control valve do?

A: It has two jobs. First the Flo-Control valve acts as a check valve, keeping the
system flow from short-circuiting into places where it doesn't belong. Second, and just
as important, the Flo-Control valve stops hot water from migrating into a zone that's not
calling for heat.

Q: Can't I just use a swing check valve to do this?

A: A swing check valve will do the first job (preventing flow from short-circuiting), but
it usually can't do the second. The Flo- Control valve has a weighted check. When the
water in the boiler is hot, it tries to rise into the system piping. We call this gravity
circulation. The Flo-Control valve's weighted check stops gravity circulation before it
can create a problem with your customer.

Q: Should I use a B&G Flo-Control valve only on the supply

A: If you're using circulators, you need a Flo- Control valve on each supply line, but
you might need one on each return line as well. Gravity circulation doesn't need a
complete circuit; it can happen in a single pipe. The hot water rises up the pipe as the
cold water falls. If a radiator on the return side of your zone overheats, install a B&G
Flo-Control valve on the return. That solves the problem just about every time.

Q: Why does a B&G Flo-Control valve have two inlets?

A: So you can use it in a horizontal line, or as an elbow. The Flo-Control valve's model
designation, "SA," stands for "straight" and "angle." We make them this way for your
piping convenience.

Q: Can I use the "extra" inlet for anything?

A: You can use it as a place to install a boiler-bypass line. You'll need a bypass if
you're putting a low-volume boiler in a high- volume system (such as an old gravity hot
water system).

The bypass gives you a way of raising the temperature of the returning water; and that
helps to keep the flue gasses from condensing. Run the bypass only from the bottom
tapping of the Flo-Control valve to the boiler return. If your circulator is on the return,
pipe the bypass into the circulator's inlet side.

Use a B&G Circuit Setter valve in the bypass line to balance the flow between the
system and the bypass line.

Q: Do I need B&G Flo-Control valves if I have a
primary/secondary system?

A: If the secondary circuit is above the primary circuit, it's a good idea to install a
Flo-Control valve on both the supply and return lines of the secondary circuit. If the
primary circuit is higher than the secondary, you probably won't need the FloControl
valves unless the secondary circuit contains a boiler.

Q: If I use zone valves, do I still need B&G Flo-Control

A: Not on the side of the system that has the zone valves, but you may need them on
the other side. It all depends on how you run your piping, and how close your boiler is
to a radiator that might overheat from gravity circulation. Sometimes you can have
gravity circulation and not even notice it! It all depends on where the radiators are.

Q: What is the purpose of the knob on the top of the B&G
Flo-Control valve?

A: If you turn the knob counter-clockwise, you'll lift the weighted check off its seat.
This will give you gravity circulation, which you may want if the circulator should fail.
Once you've repaired the circulator, turn the knob clockwise to reseat the weighted

Q: Is there much of a pressure drop across B&G
Flo-Control valves?

A: There's just enough to make the Flo- Control valve work effectively. For instance,
with three gpm flowing through a three-quarter-inch Flo-Control valve, the pressure
drop will be about 2-1/2 feet. For six gpm flowing through a one-inch Flo- Control, the
pressure drop will be about 11/2 feet. We have charts available that show the pressure
drops for all our valves. If you need to know, just call!

Q: What size B&GFlo-Control valve should I use?

A: Usually line size, but you might want to use a larger Flo-Control valve on a volume
boiler that comes up to temperature very quickly. Quick-start boilers sometimes
produce enough thermal lift to raise the weight of a line-size Flo-Control valve.

Q: Do B&GFlo-Control valves make noise?

A: B&G Flo-Control valves have a patented design that eliminates noise. When the
flow from the circulator lifts the weighted check, it also tilts it a bit to the side (that's the
idea we patented!). This slight tilt of the weighted check on its stem keeps it from
"chattering" as the water flows by. It's a small detail, but it's one of the things that makes
the B&G Flo-Control valve so reliable.

(If you have a question about B&G Flo- Control valves, and you didn't find your
answer here, call your ITT Bell&Gossett representative. They're the people with the
answers to all your hydronic heating needs!)
[Return to CyberPress] [Stories by Title]
Old 01-13-03, 04:37 PM
KField's Avatar
Join Date: Dec 2002
Location: Easton, PA
Posts: 3,245
Received 0 Votes on 0 Posts
You did mention the flow check and that could be the problem. The other possibility would be if a thermostat for one zone is controlling a circulator on another zone. It is easy to do and sometimes hard to find.

Try isolating the overheating zone with a manual valve and see how the other zones react.
Old 01-14-03, 06:29 AM
Visiting Guest
Posts: n/a

THANKS A TON - Very helpful!
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: