Can't Get Water to Flow Through New Radiant Zone

PilotPat24

Hi Guys,

I just installed a couple of radiant zones and I can't seem to get water to flow through the system.

There are five loops on one of the zones.  I was able to have water flow through the end of each of the five loops before I installed the pex onto the return radiant  manifold.  Those manifolds are to the right.  The manifolds to the left are for the second zone which I haven't tried to run yet.

There is an Indirect HWH zone, and a zone with a recessed radiator which are both working fine on the boiler.  

The mixing valves for the radiant zones are 1" with 1" pipe leading to the 1" radiant manifold before splitting off the 1/2" pex loops.

The circulator is located on the return side of the boiler.

Please let me know any other information you would need from me.  Thanks in advance!

Pat

Mad Dog_2

I can't see your purge station.  Its best to purge cold, I find.  Sometimes you have to open up the Mixing valves one at a time, keep all the other manifolds closed and do one loop at a time.  Keep pressure up. Some further back pics would help. Hard to see the whole job.   Mad Dog 🐕 

PilotPat24

I guess I don't have a purge station.  I have one of the loops.disconnected from the return manifold at the moment and I am using that inlet as a purge station currently.

PilotPat24

Mad Dog_2 said:

I can't see your purge station.  Its best to purge cold, I find.  Sometimes you have to open up the Mixing valves one at a time, keep all the other manifolds closed and do one loop at a time.  Keep pressure up. Some further back pics would help. Hard to see the whole job.   Mad Dog 🐕 

Hi Mad Dog.  What do you mean by opening up the mixing valves?  Turn it open to the hottest temperature?

Thanks,

Pat

PilotPat24

More pictures

PilotPat24

PilotPat24

Okay so I'm am running one loop at a time with the mixing valve maxed out right now and they heating up.  I have done 2 out of the 5 loops so far.  I will keep you posted.

neilc

what do you have for circulator(s)?
is it enough to pull from 3 or 4 manifolds, and their loops,
I'm betting not,

I think you're gonna need a separate circ pulling from each mix valve mix port, lose the zone valves,

what are the 3rd and 4th zones?

hot_rod

Unusual piping with the zone valve on the hot supply to the mix valves?

Zman

You need to have a circulator within the mixed loop. Otherwise, there is no flow to the loop when the valve starts closing.

PilotPat24

The Zone Valve all the way to the left is for the Indirect HWH.  The Zone Valve all the way to the right is for a recessed radiator.

PilotPat24

This is the current boiler circulator.

PilotPat24

Zman said:

You need to have a circulator within the mixed loop. Otherwise, there is no flow to the loop when the valve starts closing

Hi Zman.  Doesn't the mixing valve open and close the cold inlet coming into the mixing valve?

Thanks, 

Pat

hot_rod

The line that says Mix needs to have a circ
The circ pulls hot and cold through the mix valve and overcomes the pressure drop in the tube circuits 

You have the correct pump maybe not in the correct location 

PilotPat24

hot_rod said:

The line that says Mix needs to have a circ
The circ pulls hot and cold through the mix valve and overcomes the pressure drop in the tube circuits 

You have the correct pump maybe not in the correct location 

Ah okay.  So I need to have a circulator between the mixing outlet port and the radiant supply manifold for each radiant zone?

And then I would also ditch the zone valves for each radiant zone?

EdTheHeaterMan

Where are the circulators located?

You need them somewhere between the Mix port of the mixing valve (M) and the tee (T) on the return that goes to the cold port (C) on the mixing valve
Top diagram may not get heat because there is nothing moving the water in the low temperature loop. add a circulator to the low temperature as shown in the bottom diagram loop, and you will move the water

Zman

PilotPat24

EdTheHeaterMan said:

Where are the circulators located? you need them somewhere between the Mix port of the mixing valve and the tee on the return that goes to the cold port on the mixing valve

Right now the one circulator controls all 4 zones.  The circulator is currently on the return side of the boiler just before the water returns back into the boiler.

EdTheHeaterMan

@hot_rod , @Zman and what @EdTheHeaterMan said = what @PilotPat24 said

Ah okay. So I need to have a circulator between the mixing outlet port and the radiant supply manifold for each radiant zone?

What a difference a half hour makes!

PilotPat24

PilotPat24

EdTheHeaterMan said:

@hot_rod , @Zman and what @EdTheHeaterMan said = what @PilotPat24 said

Ah okay. So I need to have a circulator between the mixing outlet port and the radiant supply manifold for each radiant zone?

What a difference a half hour makes!

What?

EdTheHeaterMan

PilotPat24 said:

What?

At 9:33 @hot_rod said The line that says Mix needs to have a circ
and before he posted that comment I started my drawing that better explains that and @Zman was looking up the diagram he posted. By 10:04, Zman and I posted out answers without seeing Hot_Rod's post. We all saw the same thing at the same time. So I made a comment that we all were thinking of what your problem might be at the same time.

After I posted my comment, then refreshed my screen I saw Zman's and Hot_Rod's post and your reply. It just seems that we all had the same idea at once.

Sorry for the confusion!

PilotPat24

Ahhh.  All good!  Thanks for all of your help everyone.

So I guess everyone is in agreement that a circulator needs to be placed after the mixing port for the radiant zone.

What would be the easiest way to wire up the radiant zone circulator?  Could I be able to utilize the end switch on that zone valve to activate some type of relay to provide 110v to the circulator for the radiant zone?

EdTheHeaterMan

https://www.supplyhouse.com/Taco-SR506-4-6-Zone-Switching-Relay
They come in 3, 4, and 6 zone

I can diagram you up what I would do if you can tell me all about your system. How many high temperature zones, how many low temperature zones and how the pipes branch off from the main in order to know what circulator need to operate and when

The first place to start is with the piping and pump design

You can draw that on a piece of paper like Hot Rod does. Maybe some pictures of your boiler from far enough back to see the location of all the pipes from different positions.

Since you need to do some repiping for the circ pumps maybe we can eliminate some of the zone valves or make one low temperature mixing valve with several zones off of that mixing valve. How many temperatures do you need? How many zones do you need?

PilotPat24

Thanks for helping me out.  I appreciate it.  

Zone #1 Indirect HWH
Zone #2 Second Floor Radiant
Zone #3 First Floor Radiant
Zone # 4 Single Cast Iron Radiator 

If possible, I'd like to keep it as simple as possible and try to utilize as much as I currently have.

EdTheHeaterMan

I just saw your pictures and I have an idea. Give me some time to mark up one of the pictures to something that will work for you. Look for it tomorrow morning

PilotPat24

EdTheHeaterMan said:

I just saw your pictures and I have an idea. Give me some time to mark up one of the pictures to something that will work for you. Look for it tomorrow morning

Great!  Looking forward to seeing it tomorrow!  Thanks again and have a good night!

EdTheHeaterMan

Here is the piping changes you need to make. Click on the Screenshot file below, zoom in to see the details.
Add the low temperature circulator pumps as shown. Taco 007F or equal should be all you need.

Move the fill valve to the expansion tank location. Adjust the PRV and the expansion tank to the same pressure. About 12 PSI

Add a drain valve to the return side of the radiant manifold (on both, I only illustrated one). By closing all the loop valves and then opening one loop at a time, you can purge that loop then close them off and move to the next, until all the loops are done.

Wiring to follow.

hot_rod

You could just add two circs at each mix valve. When that zone valve opens, it would turn on the circ

Thermostat turn on zone valve, zone valve turns on circ.

That would be the simplest piping change. Another couple relays however

EdTheHeaterMan

Here is the wiring plan. There is a lot going on here. You are using a zone valve for the DHW so we need to fool the boiler control to operate at high temperature for DHW operation and at the reset temperature when operating for the heat zone(s). Since there is only one boiler circulator then the wire to operate the system circulator and the DHW circulator must be connected to that circulator. See the upper right section where there is a yellow and a red wire connected to the same "System Circulator" I have faded out the DHW circulator to indicate that there is no DHW pump.

The DHW thermostat (Aquastat) needs to be wired in to the Taco Control. That will set the Priority DHW so the low temperature space heating zones will not operate when you need to charge the DHW tank with heat. The Radiator zone may operate at the same time as the DHW zone if both call for heat at the same time. Note the dip switch settings on the Taco SR503 EXP. (must use the EXP to get all the features https://www.supplyhouse.com/Taco-SR503-EXP-4-3-Zone-Switching-Relay-w-Priority?_br_psugg_q=sr503)

The Right X X from the Taco Zone control is for Priority hot water and that will operate the DHW zone valve as I have wired it. The end switch from the DHW zone valve will then go to the DHW aquastat terminals on the boiler. With this design your boiler will operate at high temperature for DHW and will operate on RESET temperature for Space Heating.

The Left X X is for space heating and will get connected to the Thermostat location on the boiler as indicated. The red end switch wires from the Radiator Zone Valve will also get connected to the thermostat location on the boiler.

I attached the diagram as a file, so you can zoom in easier to see the details.

Available for questions if needed.

Mad Dog_2

Pat..just curious 🤔?...did someone give you a sketch to work off of or did you wing it?  If you're taking stuff apart, you've got to put in a Ball valve on the return and a tee with a boiler drain ahead of it....a basic purge station.  Then when you're all done repiping and following Ed & HR's advice, use those Manifold loop Stops to purge one loop at a time, then close off.  

Yes, do it with boiler cold first.  Yes, make sure the Mixing valves are Full open when you purge to burp the baby 👶 😉.   I didn't see them, but I like more thermometer gauges, in line.  One on mixed temp outlet and one on return.  The manifolds often have them, but too tiny and don't always hold  up great.  Mad Dog 🐕 

PilotPat24

Mad Dog_2 said:

Pat..just curious 🤔?...did someone give you a sketch to work off of or did you wing it?  If you're taking stuff apart, you've got to put in a Ball valve on the return and a tee with a boiler drain ahead of it....a basic purge station.  Then when you're all done repiping and following Ed & HR's advice, use those Manifold loop Stops to purge one loop at a time, then close off.  

Yes, do it with boiler cold first.  Yes, make sure the Mixing valves are Full open when you purge to burp the baby 👶 😉.   I didn't see them, but I like more thermometer gauges, in line.  One on mixed temp outlet and one on return.  The manifolds often have them, but too tiny and don't always hold  up great.  Mad Dog 🐕 

Here is a picture of the boiler drain, tee, and valve.  It's tough to see from the picture but it's there.  

I am going to order all of the parts today and I will let you know how I make out later in the week when I do the install.

Thanks for all of your help everyone.  I really appreciate it.

Pat

EdTheHeaterMan

Were you able to open the files with the diagrams?

PilotPat24

EdTheHeaterMan said:

Were you able to open the files with the diagrams?

Yes I did! Greatly appreciated! I will let you know how I make out in a few days.

PilotPat24

Thanks again!

PilotPat24

I got the radiant zones up and running over the weekend! Just need to dial in the mixed water temperatures for each zone. I'll upload a couple of pictures once I get everything all cleaned up. Thanks again for everyone's input and suggestions!