Hello, I have a boiler that heats and does water for my whole house.
Radiant heat, super store on the water tank. I have circulators on
every radiant zone, which seems fine. My question is that there is
one circulator that comes off the supply of the boiler and feeds the
"loop" that passes by each zone and then returns to the boiler. It is
my understanding that the zones turn on when they call for heat and
draw from the "loop" but that the circulator on the loop is always on
heating the loop to 180 degrees. I have seen other boilers that don't
have a circulator on the supply pipe and don't have a "loop". It
seems inefficient to me to have this always on and heating even if no
zones are asking for hot water, and this seems validated by the fact
that the room for the furnace is very warm all the time (great for
drying mittens). I am thinking of getting this circulator wired so
that it only turns on if one of the others turn on. Any thoughts from
anyone? TIA, ACS

On Wed, 05 Mar 2008 11:54:20 -0800, freeacs wrote:

Hello, I have a boiler that heats and does water for my whole house.
Radiant heat, super store on the water tank. I have circulators on
every radiant zone, which seems fine. My question is that there is one
circulator that comes off the supply of the boiler and feeds the "loop"
that passes by each zone and then returns to the boiler. It is my
understanding that the zones turn on when they call for heat and draw
from the "loop" but that the circulator on the loop is always on heating
the loop to 180 degrees. I have seen other boilers that don't have a
circulator on the supply pipe and don't have a "loop". It seems
inefficient to me to have this always on and heating even if no zones
are asking for hot water, and this seems validated by the fact that the
room for the furnace is very warm all the time (great for drying
mittens). I am thinking of getting this circulator wired so that it
only turns on if one of the others turn on. Any thoughts from anyone?
TIA, ACS

Quick question:

Let us presume you have 4 room zones, plus one for the potable hot water
tank, for a total of 5. Do all 5 zones have check valves for one way hot
water flow?

Pretend that one room zone is in the attic, and has a much lower R-factor
insulation than the other 3 room zones. This thermostat will request hot
water more than the others. In some installations, without check valves,
when only one pump turns on, the output manifold of the boiler(s) that
feeds all 5 pumps will draw hot water from all connections on the
manifold. In short, one pump turns on, and the other zones are going to
have reverse flow (complex relationship to determine the percentage each
off-line pump feeds the flow to the on-line pump.)

If you have check valves on each zone leg off the manifold, then reverse
flow won't occur. And the return copper line from each off-line zone
should be cool, (not hot!)

There-fore, please post back if you have check valves on each room zone
plus the potable hot water tank zone.

"Phil Again" wrote in message
...
On Wed, 05 Mar 2008 11:54:20 -0800, freeacs wrote:

Hello, I have a boiler that heats and does water for my whole house.
Radiant heat, super store on the water tank. I have circulators on
every radiant zone, which seems fine. My question is that there is one
circulator that comes off the supply of the boiler and feeds the "loop"
that passes by each zone and then returns to the boiler. It is my
understanding that the zones turn on when they call for heat and draw
from the "loop" but that the circulator on the loop is always on heating
the loop to 180 degrees. I have seen other boilers that don't have a
circulator on the supply pipe and don't have a "loop". It seems
inefficient to me to have this always on and heating even if no zones
are asking for hot water, and this seems validated by the fact that the
room for the furnace is very warm all the time (great for drying
mittens). I am thinking of getting this circulator wired so that it
only turns on if one of the others turn on. Any thoughts from anyone?
TIA, ACS

Quick question:

Let us presume you have 4 room zones, plus one for the potable hot water
tank, for a total of 5. Do all 5 zones have check valves for one way hot
water flow?

Pretend that one room zone is in the attic, and has a much lower R-factor
insulation than the other 3 room zones. This thermostat will request hot
water more than the others. In some installations, without check valves,
when only one pump turns on, the output manifold of the boiler(s) that
feeds all 5 pumps will draw hot water from all connections on the
manifold. In short, one pump turns on, and the other zones are going to
have reverse flow (complex relationship to determine the percentage each
off-line pump feeds the flow to the on-line pump.)

If you have check valves on each zone leg off the manifold, then reverse
flow won't occur. And the return copper line from each off-line zone
should be cool, (not hot!)

There-fore, please post back if you have check valves on each room zone
plus the potable hot water tank zone.

That's a primary loop. Often that circulator is controlled by an outdoor
temperature sensor working through a controller like Tekmar to determine the
optimal temperature for the system

"Phil Again" wrote in message

Let us presume you have 4 room zones, plus one for the potable hot water
tank, for a total of 5. Do all 5 zones have check valves for one way hot
water flow?

Not a check valve, but they do have a flow valve that acts as one.
This is one of a few b rands that will work. They can be opened in case of
circulator failure for gravity flow.


Pretend that one room zone is in the attic, and has a much lower R-factor
insulation than the other 3 room zones. This thermostat will request hot
water more than the others. In some installations, without check valves,
when only one pump turns on, the output manifold of the boiler(s) that
feeds all 5 pumps will draw hot water from all connections on the
manifold. In short, one pump turns on, and the other zones are going to
have reverse flow (complex relationship to determine the percentage each
off-line pump feeds the flow to the on-line pump.)

That is called sloppy design and installation.

On Wed, 05 Mar 2008 17:55:54 -0800, freeacs wrote:


That's a primary loop. Often that circulator is controlled by an
outdoor temperature sensor working through a controller like Tekmar to
determine the optimal temperature for the system


Well, I don't know if there are check valves as I am not a plumber. I
will check if the return is cool from each return. I would think not
having check valves (and having reverse flow) would be quite bad, is
this common? Is it a good/bad idea? Would a check valve make a
difference in how things should perform? ACS

I don't know about outdoor sensor controlling a circulator.

I don't know how common not having a flow valve (check valve?) is. The
system I lived with didn't have them. Yes, it was not a good idea not
having them. I was told expensive (Labor cost mostly) and they fail.
Experts can comment on that statement.

What I was thinking, and it is only my thinking, a zone circulator pump
will draw hot water from the manifold. The pump will draw from the
manifold the least resistance source of hot water. If there is a primary
loop with a pump, wouldn't the source of least resistance flow of hot
water be from the boiler? Thus the reverse flow should be minimized,
yes? But then again, maybe even in this plan, a reverse flow inhibitor
might still be needed.

On Mar 5, 2:54*pm, wrote:
Hello, I have a boiler that heats and does water for my whole house.
Radiant heat, super store on the water tank. *I have circulators on
every radiant zone, which seems fine. *My question is that there is
one circulator that comes off the supply of the boiler and feeds the
"loop" that passes by each zone and then returns to the boiler. *It is
my understanding that the zones turn on when they call for heat and
draw from the "loop" but that the circulator on the loop is always on
heating the loop to 180 degrees. *I have seen other boilers that don't
have a circulator on the supply pipe and don't have a "loop". *It
seems inefficient to me to have this always on and heating even if no
zones are asking for hot water, and this seems validated by the fact
that the room for the furnace is very warm all the time (great for
drying mittens). *I am thinking of getting this circulator wired so
that it only turns on if one of the others turn on. *Any thoughts from
anyone? *TIA, ACS

INSULATE THE PIPING IN EITHER CASE

Are you sure that each loop has a circulator and not a zone control
valve?

"Phil Again" wrote in message
...
On Wed, 05 Mar 2008 17:55:54 -0800, freeacs wrote:


That's a primary loop. Often that circulator is controlled by an
outdoor temperature sensor working through a controller like Tekmar to
determine the optimal temperature for the system


Well, I don't know if there are check valves as I am not a plumber. I
will check if the return is cool from each return. I would think not
having check valves (and having reverse flow) would be quite bad, is
this common? Is it a good/bad idea? Would a check valve make a
difference in how things should perform? ACS

I don't know about outdoor sensor controlling a circulator.

I don't know how common not having a flow valve (check valve?) is. The
system I lived with didn't have them. Yes, it was not a good idea not
having them. I was told expensive (Labor cost mostly) and they fail.
Experts can comment on that statement.

What I was thinking, and it is only my thinking, a zone circulator pump
will draw hot water from the manifold. The pump will draw from the
manifold the least resistance source of hot water. If there is a primary
loop with a pump, wouldn't the source of least resistance flow of hot
water be from the boiler? Thus the reverse flow should be minimized,
yes? But then again, maybe even in this plan, a reverse flow inhibitor
might still be needed.

On any hydronic system there is either going to be flow checks or zone
valves to prevent reverse flow. Today, you can get the flow check built into
the circulator

On Mar 6, 3:22*pm, wrote:
Are you sure that each loop has a circulator and not a zone control
valve?

I am pretty sure it is a circulator, they are all the same green
things with electronic connections. I don't know if these are "zone
control valves" as I don't know what that is. I have insulated all the
pipes (though not that well as there are so many connections it is
hard to get the insulation around enough). I have asked my
electrician to check out how he has it hooked up. I guess I will ask
the plumber to tell me how things are hooked up as well and if there
would be any reverse flow. Thank you all for your comments. ACS

"Phil Again" wrote in message

I don't know how common not having a flow valve (check valve?) is. The
system I lived with didn't have them. Yes, it was not a good idea not
having them. I was told expensive (Labor cost mostly) and they fail.
Experts can comment on that statement.

Mine are trouble free for 30 years. Cost? Almost nothing in labor as it is
a simple sweat joint or threaded joint, nothing complex at all.

"beecrofter" wrote in message

INSULATE THE PIPING IN EITHER CASE

Maybe. That heat loss is not lost, it goes into the house that you are
trying to heat anyway. If there is an area you don't want to heat
insulation helps.

Each part usually has a nameplate with a manufacturer name and part
number. By going to the manufacturer's web sit you can identify each
part and its function. My guess is that you have zone valves not
circulating pumps on each loop. The zone valve is basically an
electrically controlled on/off valve. When the thermostat call for
heat the vale opens and allows water to flow. When the thermostat
stops callong for heat it closes and prevents flow. This also explains
why you do not have a separate flow control valve. As to why the pump
runs 100% of the time, you need to ask the plumber.

On Mar 6, 7:26*pm, wrote:
On Mar 6, 3:22*pm, wrote:

Are you sure that each loop has a circulator and not a zone control
valve?

I am pretty sure it is a circulator, they are all the same green
things with electronic connections. *I don't know if these are "zone
control valves" as I don't know what that is. I have insulated all the
pipes (though not that well as there are so many connections it is
hard to get the insulation around enough). *I have asked my
electrician to check out how he has it hooked up. *I guess I will ask
the plumber to tell me how things are hooked up as well and if there
would be any reverse flow. *Thank you all for your comments. ACS