Do I have a leak ?

jtorral

First of all. I am new to the community and glad to be here.

This is my first home with underfloor heating in concrete floors and I am wondering if I have a leak in the line?

I just bought the house which is about 20 years old and its been one surprise after the other. So I am hoping this does not totally destroy my hopes or desire to be in the home which has turned into a money pit.

Having said that, I have attached a few images for review and feedback. Is it a leak or not ???? That is the million dollar question.

Jamie Hall

Well... it doesn't look wonderful. However, it may not be a leak. It may simply be a location where the radiant pipes are closer to the surface of the floor. That happens, more often than people would like to admit.

You can positively decide if you have a leak or not, though -- and it shouldn't be hard. At your boiler, there will usually be a feed pipe which goes from your domestic hot water to the boiler, and that should have a shutoff valve on it (as well as, most likely, a pressure reducing valve and quite likely a backflow preventer... we hope...). If you can find that, close the shutoff valve. And then keep track of the pressure (there will be a gauge on the boiler). If the pressure drops and keeps dropping... that's not good. On the other hand, if it doesn't, you don't have a leak.

STEVEusaPA

How log was this loop running before you shot the pic.
Turn off your automatic water feed and see if you lose pressure.
Also take some shots after the loop is off for 1/2 hour, 1 hour, and cold and first comes on.
I would suspect a leak would be a bigger 'puddle' after a long on time.

jtorral

ok. this is getting above my brain capacity Here is what I know and maybe it will help answer your questions.

Look at the attached photo. Excuse the horrible config. Its what I bought and I just replaced the water heater tank with a tankless one as you can see in the photos. Why? In 24 days, the heater consumed 1120.00 worth of LPG.

You can see the feed line from the house going into the left side of the blue expansion tank. That line is closed.

The blue expansion tanks was just replaced. 2 days ago since the older one was too small and the pressure was at 40psi . After the expansion tank was replaced, the plumber supplied water to it and it pressurized at about 22 PSI.

With the system completely off, and cold water not running, the pressure drops to 2 psi. Once it heats up, it maintains a steady pressure of 28 PSI.

There is another valve you can see in the picture. It has a red label on the top of the knob. Its just above the circulator pump to the left. That valve has to be almost completely open in order for the tankless heater to turn on the burner. The circulator pump comes on when an actuator opens but the burner will not fire unless that valve is almost completely open.

Yes, the circulator pump is installed on the wrong axis and will be fixed tomorrow.

Thanks for the time to look at this stuff.

STEVEusaPA

Well that's a colossal sh#t show. Your system shouldn't be running anywhere close to 28 psi. That flex pipe has to go.

Jamie Hall

As @STEVEusaPA said, you don't need -- or want -- 28 psi. At most it should be 15 psi cold, 20 psi hot. But -- I'm led to wonder: was the new expansion tank properly precharged? And if so, to what pressure? Unhappily, I don't see the valves for it which would allow you to check that easily -- so I'm not sure what to suggest. It should have been charged with air to just below the system cold pressure (15 psi) when it was disconnected from the system...

I'm still not sure you have a leak, as a poorly precharged expansion tank could show that much pressure change. May I ask you to bring the pressure up to 12 psi with the system cold, and then find a valve to shut off the water supply from the house (I don't see one, but there must be one somewhere) and let it sit and see what the pressure does?

I'm not at all surprised that that control valve has to be almost all the way open to get the tankless to fire up. Tankless heaters are intended for domestic hot water, not heating, and require a certain minimum flow to operate. They also have a very high head loss in comparison to a proper boiler, so the pump is probably operating very close to its limits.

jtorral

quick update.

Latest thermal images show nothing there whatsoever. Go figure.