Isolating a Loop

antigodave

New to the forum. I am recently working from home and noticed my well pressure switch going on and off intermittently every few minutes. I tracked the problem down to a leak in my radiant heating tubes in my garage. I have 2 loops, and when I shut the valve off to my garage manifold, my well pressure holds fine.. I would like to isolate each loop to determine what loop is leaking. I see I can turn off my circuit balancing valve on the return header; however, there is no place to use the vent key to turn off the flow meter shut off. (the original contractor even has the key tie wrapped right next to the flow meters. Question 1 : How do I isolate one loop without installing a ball valve or shut off.
Question 2: If I have to install a ball valve, how do I fill the system and eliminate the air with the fittings installed on the manifold - a garden hose doesn't screw on.

antigodave

Sorry: here are a couple of pictures that show the system. Forgot to post with original.

hot_rod

I use these vice grip pinch off tools.

The red caps are shutoffs,turn them clockwise to close that port, use the pliers on the other side, at least until you install a pex ball valve.
On some manifolds those flow setters are also shut off valves, here is what they look like on the Caleffi manifolds. The locking cap is also the wrench to close off the flowmeter.

Do yours spin?, they may be valves.

infloorradiantheat

hot rod,
Do the Caleffi manifolds shut off both sides of the loop (the water entering and water leaving)?

hot_rod

yes

infloorradiantheat

Excellent! When we replaced our basement manifold we had to have a custom one made with shut off ball valves on each loop at the entrance and exit points. At the time the contractor could not find one that allowed us to shut off each individual loop from both directions in order to search for a leak by isolating a loop. But the custom made one was very large and would not fit in our upper floor closets. I looked up the specs on the Caleffi ones but couldn't tell if the flow control knob was actually a shut off knob. Is this an example of one where I could shut off each of the individual 7 lines on both ends in order to isolate a leak on one of the 7 lines?
https://www.supplyhouse.com/Caleffi-6686G5S1A-INVERTED-1-TwistFlow-Manifold-w-Temp-Gauge-Inverted-PEX-Outlets-7-Outlets

antigodave

The flow meters themselves spin; however, it doesn't seem like they are shutting off. On the Rehau website it shows the key (which the contractor tie wrapped in my original pictures) being used to turn off the flow (see pic), but my meters are missing the square connection out the top. .

Also, it seems like my pex is very ridgid. Won't a pliers like that permanently damage the pex?

If I lose liquid, how do I remove the air from the system those types of connections?

Thanks.

Zman

Cutting in a ball valve is probably your only option at this point.

hot_rod

If you shut off the red and blue valves, relieve the pressure with the drain cocks, you can pop in a valve fairly easily and quickly. Shouldn't lose but a cup of fluid,if you work quickly.

Looks like them male adapter has been leaking on one manifold, not sure how deep into this repair you want to get?

Sounds like you may need to chop up concrete, or abandon a loop?
If you go with just one loop, may as well get rid of the manifold and connect pex to copper?

An IR camera can usually show where small leaks are quite accurately.
Or once you isolate the bad loop put 100 psi air on it, I've had leaks located with listening devices by Leakbusters.com

Some air with some water at 100 psi makes a gurgling sound that the receivers pick up easily. That is how LB did some snowmelt leaks for me, quicker than heating up a large driveway .

antigodave

Thanks Bob. I took the first loop (thought I had a 50/50 chance of selecting the leaking loop), had everything ready, valve set to off, cut the line, put on the valve - almost no water (maybe a couple of tablespoons) lost. Shut that side off. Damn leak in the other side. Put a valve in the other side same thing. Both loops have a leak..... one is much greater than the other, but back to square one. Has anyone every used something like GeoLoop Leak seal for radiant tubing? If so how good does it work and how do you install?

hot_rod

I had one success one not, with this product.
If you try a sealer make sure it is a hydronic specific. Not an automotive stop leak.
A pinhole maybe, a severed tube, probably not.