Dripping water at copper to plastic connection question

Pheraph · January 20

Good evening,

In October or November I my house wasn't heating properly, followed the instructions from a previous post purged the air from the system and left it around 12 psi. Everything seemed to be working fine, but now I noticed a small drip coming from the system. Looking at the pressure, it seemed a bit high at 50 psi even though I left it around 12 psi when I initially purged the air. Is it normal for pressure to rise that high? I am concerned that is what might be causing the drip from the copper - plastic tube connections. What are your thoughts?

My previous post here, which helped tremendously is below.

Thank you for your time!

Radiant Heating Pump pulling power, 0 GPM output. Advice Appreciated

Pheraph

Jan 13, 2024

Good morning,

Figures right as it gets cold the Radiant Heating System stops working. Looking at the Pump, it is pulling power and I can hear it spinning faster if I turn up the speed. But it is only putting out 0-1 GPM according to the reader. Looking at some other posts they say there could be air in the system. I had the pump replaced a year ago, so I think it should be fine. I believe the red valve above the pressure gauge is for purging the system correct? If I drain it, do I need to refill it from another source or will it pull directly from the water heater? I haven't done this myself, but I am confident I can after verifying some things. Anyone have thoughts or suggestions before I start? Any help is appreciated.

EBEBRATT-Ed · January 20

pressure is to high. Your PRV valve that feeds water to the boiler could be leaking by or it could be the expansion tank. Pressure should be 12-15psi.

hot_rod · January 20

it looks like the leak may be in the sweat joint above the crimp ring

mattmia2 · January 20

see my comments about the expansion tank on that thread.

er….I was thinking of another thread but most likely your expansion tank lost its precharge or is bad.

mattmia2 · January 20

Pheraph · January 20

Ah, thanks. I should probably call someone out to fix that then. Don't want to risk messing something up. Unless it is relatively easy, are Expansion tanks easy to swap out?

Larry Weingarten · January 20

Hi, It looks like Uponor PEX has been mixed up with a copper crimp ring. Shouldn't the fitting in the T be Uponor and the ring be the same as the other expansion rings used? A soldered fitting that didn't quite take, seems possible too.

Yours, Larry

Pheraph · January 20

Is there a way for me to lower the pressure until I can get a contractor to come out? I am concerned there are potential leaks I cant see under the flooring.

hot_rod · January 20

https://forum.heatinghelp.com/discussion/comment/1836537#Comment_1836537

I think all of the expansion pex brands now accept crimp rings as an option.

When it is changed it could become an expansion adapter.

Maybe it was done by someone that didn't own the expansion tool?

Larry Weingarten · January 20

Hi @hot_rod , Didn't it used to void the warranty if different systems were mixed up? Also, some of the insert fittings I've seen are a bit rough, looking like it would be easy for them to leak. And then there is the little flow restriction created … I know, nitpicky! 🤨

Yours, Larry

hot_rod · January 20

Pexhouse does a great job of explaining the listing and spec numbers on tube.

https://pexhouse.com/how-to-read-a-pex-pipe-print-stream/

If the tube has F 876 or F876/F877, then by ASTM definition the various fittings that are tested and certified are listed. I don't know that legally a manufacturer can deny using other listed fittings or brands of fittings and rings? Some of the Manufacturers don't even make their own fittings and rings. They buy them from various sources.

Same with radiant manifolds. Any pex with the correct standard listing can be used.

If you dig deep enough in their tech literature I thing the tube manufacturers state that now.

The internal bore issue is another discussion. On a hydronic loop you may only have two fittings, so no big deal.

In a home plumbing system it is a different concern. Especially with plumbers that use a lot of ells with pex, as if it is copper tube :)

Screenshot 2025-01-20 at 12.57.06 PM.png

Pheraph · January 20

I am not sure about all of that, some company nearby installed it before I bought the condo. o.O Is there a way to lower the pressure manually until tomorrow? I have a contractor coming out.

Thanks!

mattmia2 · January 20

Does the pressure go down if you turn the system off and let it cool?

Pheraph · January 20

I noticed the temp went down, pressure stayed around 40-50 psi

Pheraph · January 20

I connected a hose to the purge valve and opened that a little. gets the pressure down to 12, but once valve closes it just goes back up pretty fast.

mattmia2 · January 20

Does this boiler also heat domestic hot water or just heating. If it does DHW it could be the coil for the DHW leaking or the PRV isn't holding. If no DHW then it has to be the PRV leaking. Try turning off the manual valve to the prv.

Larry Weingarten · January 20

Hi, There is probably a pressure reducing valve that supplies water to the system. It should have a shut-off valve with it. Can you give us some photos of this valve and surrounding piping?

Yours, Larry

Pheraph · January 20

https://forum.heatinghelp.com/discussion/comment/1836582#Comment_1836582

I turned the temperature down on the system, will see if that changes anything.

Pheraph · January 21

Nope, no change in pressure oddly.

Pheraph · January 21

Contractor came out, stated he thinks there is a hole in the heat exchange coil inside the tank. When I purge the pressure from the system, the pressure jumps back up again after closing the valve. He states the pressure is coming from the hole in the potable water tank. The water/heater was turned off, so the water has been cooled. They stated I will need a new tank, that the heating exchange coil cant be swapped out since it is welded.

mattmia2 · January 21

https://forum.heatinghelp.com/discussion/comment/1836619#Comment_1836619

mattmia2 · January 21

The test for the DHW heat eachanger leaking is to turn off the cold water to the domestic hot water and see if the pressure stops going up.

neilc · January 22

um,

why isn't a Pressure Relief Safety Valve blowing off ?

( 40 - 50 psi )

Pheraph · January 22

There isnt one on this system I guess. :(

Pheraph · January 25

How complicated is it to swap out the combi tank? Had a few quotes come back with what feels like a crazy high price. If I were to get a new system, what would work best? Combi tank, combi boiler, tankless heaters? Trying to avoid spending a down payment on a house to get this swapped out. If it is easy enough to swap out the combi tank myself, I might just do that. Thoughts? I am avoiding putting the prices up since it was in the rules not to post it.

mattmia2 · January 25

is it an indirect tank type water heater or a heat exchanger inside a combination boiler or what?

Pheraph · January 25

I think heating exchanger inside combi boiler

mattmia2 · January 25

You'd probably have to get the heat exchanger from the boiler manufacturer. Probably a fair bit of disassembly to get to it but not too hard if you keep track of wat you took apart and put it back together the way you took it apart.

Dripping water at copper to plastic connection question

Radiant Heating Pump pulling power, 0 GPM output. Advice Appreciated

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