Zone 3 on boiler heats slowly

[jonblu]

I have a combination boiler with 3 zones.
Zone 1 on the bottom floor heats up quickly. This loop is 180 feet.
Zone 2 on the middle floor heats quick. This loop is 100 feet.
Zone 3 on the top floor heats slowly and pipes coming to and from boiler are cooler than the other pipes and not much heat coming out.

I tried making zone 3 the priority loop and still no strong heat. There are no zone valves in the system.

Do I need zone valves?
Would a manifold help to direct the flow of hot water to zone 3?
Can I get more heat to zone 3 by changing the supply pipes?

 

[voletl]

You need to post a picture of your boiler setup

 

[jonblu]

What do you think?

 

[voletl]

Personal opinion that that was a hack job and should be ripped out and replaced. Is this in your house?

 

[jonblu]

Yes, what is hack about it?
It does work. Zones one and 2 heat quicker and on the 3 zone eventually heats up.

 

[voletl]

Like I'm saying personal opinion if I had someone come in my house and install that I throw them out before they could solder a joint. Sidetracking, sorry

Why is every ball valve shut off including the gas cock?

 

[Diehard]

It must be assumed that having 3 circulators for 3 zones, that each zone is separately controlled by its own thermostat. So how do you compare the difference in how fast or slow they heat up?

Having zone valves would be no different than the circulators turning on and off.

I would first be sure that there is no air anywhere in that 3rd zone. Do you have air vents at all the radiators?

It is assumed that the 3 circulators are identical in size so the difference in head vs flow for the 3rd level should only be reduced slightly by the total length of piping and its resulting friction loss. Without knowing the details of the added pipe lengths and the effect on the pumps performance, we can't compare the flow difference. And whether it could make that much of a difference in flow rate.

You say you "... tried making zone 3 the priority loop and still no strong heat." How did you do that?

 

[voletl]

On the circulator control panel you can control which zone is priority over the others normally a water heater would be priority over heating. If you're using the boiler to heat a water heater.

 

[fixitron]

The most likely cause is low flow of boiler water through that loop. Since that loop has its own circulator and this is apparently a recent problem (we almost never get enough information in an original post), then I would assume that the circulator is sized appropriately. The next most likely cause is air in the loop, which would require either opening high vents to check for or release any air (if they are installed appropriately) or using a utility pump to circulate water around the loop to a bucket to eliminate air. Then there is the possibility that if internal flow-check valves are installed, it may be getting clogged with rust and debris from the heating system. There might be an "IFC" label on the motor. To be sure, you need to disconnect the flange on the inlet of the circulator and look into the circulator inlet to see if there is a plastic IFC installed. If there is, you need to pull it (carefully) to inspect it. I have found them difficult to try to clean, so you would just replace it if it is clogged (then start paying attention to water quality and flush the system and add boiler water treatment).

Making that zone "Priority" will have no effect. Priority is designed for indirect hot water heating zones so that when there is a call for hot water, that zone will take all of the heat. Using zone valves with zones with individual circulators makes no sense at all.

 

[frodo]

after you have bleed the upper floor
then check the psi at the upper floor

what psi is the system set at? on lower floor
if the psi is low then the upper floor is starved for flow
up the pressure [5 psi] for better flow on upper floors

 

[Diehard]

What?

 

[Diehard]

What model and size is the pump?
Approximate distance from boiler to highest zone piping?

 

[jonblu]

Like I'm saying personal opinion if I had someone come in my house and install that I throw them out before they could solder a joint. Sidetracking, sorry

Why is every ball valve shut off including the gas cock?

Its an old photo. I didn't want the system on at that time.

 

[jonblu]

after you have bleed the upper floor
then check the psi at the upper floor

what psi is the system set at? on lower floor
if the psi is low then the upper floor is starved for flow
up the pressure [5 psi] for better flow on upper floors

I don't have a gauge on the system. How do you adjust the pressure in one zone? I don't know if the pump is adjustable. I don't think it is. They are the same pump, the Taco 007

 

[jonblu]

What model and size is the pump?
Approximate distance from boiler to highest zone piping?

Pump is Taco 007. Do i need a larger pump for the loops with more head? Zone 3 is the top floor.

Distance from boiler to highest loop is about 17 feet.

 

[jonblu]

The most likely cause is low flow of boiler water through that loop. Since that loop has its own circulator and this is apparently a recent problem (we almost never get enough information in an original post), then I would assume that the circulator is sized appropriately. The next most likely cause is air in the loop, which would require either opening high vents to check for or release any air (if they are installed appropriately) or using a utility pump to circulate water around the loop to a bucket to eliminate air. Then there is the possibility that if internal flow-check valves are installed, it may be getting clogged with rust and debris from the heating system. There might be an "IFC" label on the motor. To be sure, you need to disconnect the flange on the inlet of the circulator and look into the circulator inlet to see if there is a plastic IFC installed. If there is, you need to pull it (carefully) to inspect it. I have found them difficult to try to clean, so you would just replace it if it is clogged (then start paying attention to water quality and flush the system and add boiler water treatment).

Making that zone "Priority" will have no effect. Priority is designed for indirect hot water heating zones so that when there is a call for hot water, that zone will take all of the heat. Using zone valves with zones with individual circulators makes no sense at all.

Would a zone valve force the water to flow in one loop and not the others? Is that what happens when one pump is on and the rest are off?

Seems like i've got to run my mix of antifreeze and water through the loop and make sure the water is clean first and then fill with antifreeze and water and make sure there's no air in the line. And also check if the Taco 007 has a flow check valve in it. I would assume not and I will check.

 

[jonblu]

Would a zone valve force the water to flow in one loop and not the others? Is that what happens when one pump is on and the rest are off?

Seems like i've got to run my mix of antifreeze and water through the loop and make sure the water is clean first and then fill with antifreeze and water and make sure there's no air in the line. And also check if the Taco 007 has a flow check valve in it. I would assume not and I will check.

When 2 zones are off and one is on, does the pump force the water to only flow through its loop or does it circulate around the 3 loops going to the path of least resistance?

 

[Diehard]

The typical 12 psi+/- setting on your PRV is equivalent to approx. 12 x 2.31 equals over 27 feet elevation head. So that would be more than enough pressure for your systems elevation head.

Being a closed loop, the added height doesn't make a difference as the pump does not see the difference in static head. What impacts the pumps difference in flow would be the added length of pipes involved in zone 3.

The Taco 007 is only good up to about 9 feet total friction loss head. To be continued.

What's this about antifreeze?

 

[frodo]

Which taco 007?
their are 4 different types with 4 different head pressures

from 5' to 20'+/-


anti freeze [ glyco] keeps the system from freezing up

 

[frodo]

When the pump is off
and the psi of the system is not high enough to maintain [head] water at the top of the zone
the water will be replaced by thousands of bubbles that turn into one big ass air lock
The air is caused by the pump turning
so YES, PSI does matter in a closed system