OK, just checking that there wasn't flow going into the slab and starving the upper floor. How do you switch between zones, are there multiple pumps, or are you using zone valves and a single pump? based on the description I would say you have only a foot and a half or so of "head" on that pump due to friction in the upper floor tubing.

Can you put up a picture of your manifold board and plumbing?

640' of tube dosn't sound like a lot of radiating area to meet 51,000 BTU/HR heat load. Are you confident in those heat load numbers? If not, what insulation is in the walls and how much of your wall is window and door and what are the window Rvalues/ufactors?

The 2 zones are Completly separate each with there own pumps. 51000 BTU is on the high side. My actual BTU requirement is 38000 based on my insulation, windows and doors. 51000 is based on worst case like if my wife turned the air exchanger on high and forgot about it. The air exchanger is set to low speed and 20 min on and 40 min off cycles. How do I attach pictures?

Click the "add reply" button under the latest post. At the bottom of the page that will open is an "attachments" selection. There you can "Chose File" on your computer and "Upload" which will upload it to this forum topic. The maximum file size is 100Kb so you may have to reduce the size or resolution of your pics before they will upload. Another way to do it is to upload your photo to a file sharing website like photobucket.com(accounts are free) and post a link to it here.

https://www.dropbox.com/sh/lngu3lilhqehpv1/AACxB-W4UmfjIbnofGAXmg_Qa?dl=0 NEW TO THIS DROPBOX STUFF, hopefully this works. Larry

OK Larry, that worked and I saw the 3 pictures. Do you have a little wider shot that shows more of the plumbing? The pic you put up shows half of a thermal reg valve off to the left and I can't really see where it is running to-from.

Please correct me if I am wrong with the following:
The pump flows across TO the RIGHT to the bottom manifold and out to the three main floor loops. Are those 3 supply manifold valves all the way open?

The fluid returns from the 3 loops to the upper manifold and passes thru the manifold valves with the black handles and those are the ones you adjusted to balance the temperature in the loops?.

The fluid then passes back TO the LEFT, thru what looks like an adjustable check valve(has a right to left arrow)? Is that all the way open?
Not quite sure why that device is there. The pump has(or should have) a built-in check valve to prevent the other zone from back-flowing this zone. IF that installed valve is not functioning properly/stuck partially closed, that could be limiting your overall flow. 
 
EDIT:  OK, had a minute to look up that taco 219 "swetchek" valve.  It is a check, but it can be forced open manually by unscrewing the thumbscrew on the top(I think there is a locknut there to secure the thumbscrew/seal teh packing) It is used to help prevent thermosiphon, but with a system that appears to be mostly horizontal like yours(thrmosiphon dosn't like horizontal runs), I doubt your system would have much issue with thermosihoning, especially with a mixer in there.

This is where a wider angle pic would help in determining the rest of the system flow and how the other zone fits into the plumbing picture.
Untill the pics, I did not catch that you had a thermal mixing valve. I gather that it outputs 125F water to the main floor zone. What is the boiler outlet temp set for? Of course, an issue with the thermal regulator could also be causing a flow issue in this zone.

https://www.dropbox.com/sh/lngu3lilhqehpv1/AACxB-W4UmfjIbnofGAXmg_Qa?dl=0
Good morning. The tubing that goes to the manifold with the black knobs is the return and the black knobs are the isolation valves. The tube that goes to the bottom manifolds is the inlet. And that is the manifold that I am adjusting.
It looks like my circa pump can handle 17gpm which should be fine. I now have all 3 loops adjusted within 3 degree of each other on the return lines..
I guess the only question I have left is, shouldn't I be able to get my return temp D/T less than 25 degrees? I feel if my return temp can be closer to 15 D/T my system would be better
All 3 black knobs are 100%
Thanks
Larry

So to get them within 3 degrees of each other, you just opened all three wide open? In that case, the only way I can think of to get your delta T down would be if the taco 219 swetchek is limiting the flow, which you might be able to help by adjusting as ronmar describes. I assume you have the pump on high.

Posted By garrett on 01 Nov 2015 09:42 AM
https://www.dropbox.com/sh/lngu3lilhqehpv1/AACxB-W4UmfjIbnofGAXmg_Qa?dl=0

Larry, was this supposed to be a link to more/different pics? It is the same link to the same 3 pics you posted earlier.

A pic showing your entire distribution system/panel might be helpful I think.

The heat is leaving the tubes based on your heat load. And at your flow results in a 25F drop. More flow will lower the delta, we just have to figure why your not getting it. The pump is surely capable of it.

What is your boiler temp set at?

Have you tried cycling your thermal reg valve? If it had an issue/restriction on the cool inlet side, it would only mix in enough hot water from the boiler to make your 125F outlet at a greatly reduced flow... You could pull it's core and make sure there are no obstructions in the regulator ports.

For that matter you could pull the core of that swet check and make sure there are no obstructions there either because an obstruction there would have the same effect as a thermal valve cold side obstruction

Raising the reg valve outlet temp will deliver more heat at a given flow so would probably lower your delta a bit, but it might make the floor uncomfortably warm in the process. If you lower the reg valve temp, this might make a cold inlet obstruction at the regulator more obvious as it would reduce flow overall and increase your delta...

https://www.dropbox.com/sh/lf7u4bgmzxpzkt7/AABwO6AvwrFjX3F2CIHoVjnAa?dl=0
All 3 black valves are open 100 percent on the upper manifold. I then have the lower manifold valves adjusted as follows. Loop1 open 100%. Loop 2 open 1 1/4 turn. Loop 3 open 1/2 turn. it seems like all the heat I can get out of the reg valve is 125-135 degrees it can be adjusted to a lower temp with no issues.

If I remove the core of the reg valve or sweet cock do I have to bleed the system? Boiler temp is set to 190
Thank you so much for all your help

Well with a 190F source, I would think you should be able to get a little closer to 190F out of that reg valve.

When the main floor system is running, what temperature do you see at the hot side(left) of the regulator valve?

I would expect to see around your 190F source temp there, mixing with your 90ish return temp to get your 125 out the mix port on the bottom. If you are getting 190 on the hot side, that might be a clue, but that of course depends on the regulator valve specifications.

DO you have a make and model number for tha valve as I cannot see it in the new photos.

As for inspecting the cores without completely bleeding the system, that depends on where the valves are located in your system. You can close the valves at the pump, and all 3 of those black valves on the upper manifold which will isolate the loops. I am assuming the two copper lines on either side of the thermal reg valve run to-from the boiler. Are there any valves on those lines? If so you can isolate most of the area you want to work on and inspect the valves without loosing too much water. It depends on how those two vertical pipes run to the boiler.

Got any pics of that

https://www.dropbox.com/sh/1vnkwgg485jv18r/AABQl45FBy1-7iam_08XWqN1a?dl=0

Hireturn from
The return pic piping is as follows.
Far left return from radiant floor manifold with issues, then return basement manifold, no issues. Then return from bedroom, then return from water heater
Supply pic. First pipe is the supply to the radiant manifold

I do not know the actual supply temp prior to the reg valve. Only on the right side. I believe you are correct that there is a restriction in the system. Now I just need to try to figure it out without spending a small fortune one plumber to remove and re sweet the stuff.

OK, well that explains the temp limit. That valve maxes out at 145F...

OK, it looks like you have cutoff valves for the supply and return to your main floor system where they connect to the primary loop near the boiler. If you close the pump valves and the black upper manifold valves you shouldn't have to deal with too much of the system pressure unless one of those overhead pipes has air in it storing pressure then it might burp a little when you open a fitting. Since your pipes go up and over from the valves you want to inspect, the system will have to ingest air to let the water out when you pull the cores. One trick to help keep from loosing too much water when pulling a core is to simply plug the hole and keep air from getting in which should hold most of the water in the system. A rubber glove with a small piece of rag stuffed into it can work pretty well for sealing the hole. Your air separator should get any air back out that you let in and you should have a way to add makeup water to the system correct?

Since all the fittings were sweated in place, one possibility is that there were some beads of solder that made it inside the pipe, or some other installation debris that has ultimately found it's way to the mixing valve ports and either are jamming the valve movement or plugging the internal mixing passages restricting flow for which the mixer is doing it's job and restricting supply to get it's set outlet temp. Since you can adjust the output temp, the latter is the most likely.

Yep, whoever put this together didn't have future maintenance in mind when they were doing it. They make that same reg valve with sweat-on pipe unions. It costs about 10 bucks more... IF you have to replace the valve, I would have the plumber put one of those in...

You can't measure the supply temperature into the reg valve? How did you measure the temperatures of the three loops to balance them?

Hi Ronmar
I have a laser temp gun. I did measure this afternoon the inlet temp to the regulator temp valve and it matched the furnace temp. I also this afternoon adjusted the Primary circulation pump that goes into the boiler from medium to high. My heat in the house just kicked on so I will give it an half hour or so then check my temps with the laser.

I have a different plumber coming Wed for a cleaning and I will see if he has a reg valve on his truck and I will have him replace it.

Thank you so much for staying with me and working this issue. It sucks living in a rural area where we are limited to QUALITY contractors

Yes I have a way for make up water to enter the system

Looks like my Reg Valve is AFU. I tried to adjust it from 125 degrees. To 140. Max outlet temp from the valve should only be 145 but after I checked it this afternoon the temp was at 160. It seems like it is either 125 or less or 160