Zone is not heating

jjustinia11

So, you all helped me with a big upgrade on my main zone, new circ pump, new wifi stat, iso valves, etc. This was all for my upstairs zone. Now my downstair zone will not heat up. The stat is calling for heat, the pump is spinning up, and the boiler is firing. But the heat is not getting to the basement baseboards heating.

The pipes are buried under concrete and last year when it worked fine, I could feel the heat under my feet as it traveled under my floor to the baseboard and it worked fine. Now the pipes are cold. Wehn I turn off the heat I heat the water kinda dropping in the pipes if that makes sense.

I had to drain the boiler to do the other work so I am thinking there may be air trapped. I tried opening the spout you see in the pic right before the pump and how water free flows out.

You can see in the pics there is a cut out in the concrete and there seems to be moisture there, the pipes may have a small leak. But the pressure in the boiler stays solid and it is not because the auto-fill it working (I know it is not-a problem for another day), so I am assuming that there is not a major leak in the concrete. The pipe leaving the boiler only gets hot at the top portion, not the bottom, so water is not flowing. Not sure why. I can not see where the correct place is to bleed air other than the valve in front of the pump. Take a look at these pics and please let me know what you think is going on? I don't see any bleeder on the baseboard themselves and they are tight against the wall.

Thank you,

ChasMan

Well, if everything you stated is true, I would say, It is plugged up somewhere. Not an air issue. Plugged up solid. Time to put it out of its misery for good.

Mike

When you bleed the zone, did you raise the water feed pressure? If not, try raising the pressure to 20 psi, and make sure the valve on the other pipe is open. Close both valves for the pump, maybe the one didn't seat properly.

jjustinia11

Thanks Mike!! you were exactly correct. I had all the valves open so guess water was just coming out of the bottom of the boiler vs the loop. I closed both valves raised the pressure to 20 and tons of air came out. did that like 4 time with a bucket till I felt heat in both pipes. Opened all valves again with pressure at 12PSI and the baseboard is burning hot and basement temp is rising.

Thank you.

What do you all think about the dampness in the pit? I assume there is a pin hole leak or maybe just spills from trying to bleed. Should I clean the dirt out and repair/replace the copper I can see?

ChasMan

I don't think I would touch that unless you are prepared to dig it all up. Looks fragile. You might not have to go to far to hit good copper. How old is it?

jjustinia11

So got it working and the pressure dropped to zero twice in the boiler. Closed the loop and the water in that pit dried up quickly. @HVACNUT or @ironman what do you guys think about digging it up and cutting in new copper. Don’t see signs of leak anywhere else, but you never know. I was think I might need to break back the concreate 6 inches, I heard the copper in concreate tends to be ok, as long as it is not touching rebar or something.

unclejohn

That pipe is done. Either run above or on the floor or dig it all up.

jjustinia11

I would love to run a new pipe but it goes to the far end of a finished basement. Tiles and all. Why would you think the entire line is bad. Seems like some one did a bad repair job there, maybe use the thin walled copper, you can see the repair coupling.

I see no signs of leak under the concrete or tiles. I pulled up some of the crude and corrosion off the pipe in the pit you see and that seemed to be what triggered this tiny leak.

Jamie Hall

Copper in concrete is iffish. It depends a good deal on the specific concrete. Sometimes it will last pretty well. Sometimes not so much.

If you can reach what you think might be sound copper pipe and hook into it, I would suggest that you pressure test the pipe at 3 to 5 times your working pressure, or 125 psi, whichever is more. You can use air if you prefer. The objective here is to stress the copper. If it won't hold the pressure, you're done.

Note that leaks in pipes can go down as well as up -- it is possible that there is a crack in the concrete which allows any leakage to get under the slab...

jjustinia11

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jjustinia11

Jamie Hall said:

Copper in concrete is iffish. It depends a good deal on the specific concrete. Sometimes it will last pretty well. Sometimes not so much.

If you can reach what you think might be sound copper pipe and hook into it, I would suggest that you pressure test the pipe at 3 to 5 times your working pressure, or 125 psi, whichever is more. You can use air if you prefer. The objective here is to stress the copper. If it won't hold the pressure, you're done.

Note that leaks in pipes can go down as well as up -- it is possible that there is a crack in the concrete which allows any leakage to get under the slab...

How Could I use air to pressure test? Are their special attachments to connect to a rough end of copper? It is clear there is a leak right in the middle of that pic, so would need to cut that out first for a leak to see if there is a leak elsewhere. Just attaching to the spigot would blow out the obvious leak right in that pit.

I feel like the lead is right in the center of that pic, but you never know. Air would be a great way to test. I have a compressor, small pancake.

ChasMan

They make adapters for blowing out sprinkler systems.

One of many made.

https://www.amazon.com/Camco-36143-Brass-Quick-Connect/dp/B002XL2IEA/ref=pd_sim_469_1?_encoding=UTF8&pd_rd_i=B002XL2IEA&pd_rd_r=K46FXK20FXVTCMSZ0QH5&pd_rd_w=hR93E&pd_rd_wg=dQNGj&psc=1&refRID=K46FXK20FXVTCMSZ0QH5#Ask

unclejohn

it is not a tiny leak if it dropped the pressure to zero twice.

HVACNUT

I'm sorry to say that repairing a slab leak often opens a can of worms.
It's a finished basement, but does it absolutely need to be used? Bedrooms? It would be great if you could sweat in a ball valve on the supply to isolate the basement zone so the boiler doesn't lose pressure. Then I would repipe the whole basement loop in pex and eliminate the slab piping. I would recommend replacing the circ as well.
If you have to run exposed piping, you can always box it in later.
The slab leak seems like the easy fix but it might come back to bite you, like 5 feet away from the first repair.
My home has basement in the middle, slab on left and right. I brought 2 heat loops up into the attic and down the walls to pick up the baseboard. 30% propylene glycol. Anything to get rid of the in-slab piping.

jjustinia11

> @HVACNUT said:
> I'm sorry to say that repairing a slab leak often opens a can of worms.
> It's a finished basement, but does it absolutely need to be used? Bedrooms? It would be great if you could sweat in a ball valve on the supply to isolate the basement zone so the boiler doesn't lose pressure. Then I would repipe the whole basement loop in pex and eliminate the slab piping. I would recommend replacing the circ as well.
> If you have to run exposed piping, you can always box it in later.
> The slab leak seems like the easy fix but it might come back to bite you, like 5 feet away from the first repair.
> My home has basement in the middle, slab on left and right. I brought 2 heat loops up into the attic and down the walls to pick up the baseboard. 30% propylene glycol. Anything to get rid of the in-slab piping.
>
>

I did not think about pex. There are already Gaye valves on both ends of the loop that are holding. I closed them and pulled the batteries from the Thermostat. I might be able to snake pex behind a wall that is exposed. I may need help figuring out where to connect the lines on the baseboard. I see three pipes. 1 on the left and 2 on the right all going either under ground or behind a finished wall, so don't know what is what. How thick is pex?

NY_Rob

Pex has the same outside diameter as equivalent sized copper pipe.
3/4" Pex OD = 3/4" copper pipe OD.

jjustinia11

HVACNUT said:

I'm sorry to say that repairing a slab leak often opens a can of worms.

It's a finished basement, but does it absolutely need to be used? Bedrooms? It would be great if you could sweat in a ball valve on the supply to isolate the basement zone so the boiler doesn't lose pressure. Then I would repipe the whole basement loop in pex and eliminate the slab piping. I would recommend replacing the circ as well.

If you have to run exposed piping, you can always box it in later.

The slab leak seems like the easy fix but it might come back to bite you, like 5 feet away from the first repair.

My home has basement in the middle, slab on left and right. I brought 2 heat loops up into the attic and down the walls to pick up the baseboard. 30% propylene glycol. Anything to get rid of the in-slab piping.

So I did a little digging and it is very obvious that the leaks are coming from the 2 stub out caps. the one on the left is still very wet and you could see in the dirt that is where all the corrosion is.

Does anyone know why this stub are needed? I was just going to unsweat the T from the left and the 45 on the right and redo without the stubs.

Should not take long and it will either work or not. What do you think. the other pipe looks fine (dirty but solid). I cleaned a bit of the pipe-looks shiny.


Also look under the pipe on the right, there seems to be like wet grey clay or putty??? like undried cement?? any know what that could be? do I need to worry about carbon monoxide seeping up? Should I seal this up when done?


Advice would be appreciated. I plan to unsolder this evening late.

Thank you!

Jamie Hall

Carbon monoxide? from where?? Very unlikely. Also, it looks to me as though in that area at least the pipes are not in the slab, but under it, perhaps in a sand bed. Could that be?

jjustinia11

> @Jamie Hall said:
> Carbon monoxide? from where?? Very unlikely. Also, it looks to me as though in that area at least the pipes are not in the slab, but under it, perhaps in a sand bed. Could that be?

Yes, it is definitely under the slab and there is a fine sand it is in. In the finished basement I have not idea. I was under the impression that carbon monoxide could seeps up from under ground when the slab is compromised, rarely.

BobC

Your thinking of radon, not carbon monoxide.

To me that copper looks like it was attacked by the concrete mix, some concrete is very aggressive. If you attempt to repair it I would sleeve the copper with something to keep fresh concrete away from it.

Bob

jjustinia11

> @BobC said:
> Your thinking of radon, not carbon monoxide.
>
> To me that copper looks like it was attacked by the concrete mix, some concrete is very aggressive. If you attempt to repair it I would sleeve the copper with something to keep fresh concrete away from it.
>
> Bob
Ok. On radon. The pipe you are looking at was never in concrete. But hear you I would protect it better. Any thoughts on the stubs. Why are they there. The caps are what seem to have failed?

The square cut out in the concrete was done long ago by previous owner these pipe were a repair put in and left in the dirt as you saw in first pics. I just cleaned it out.

jjustinia11

So when I open the spout to make sure there was no water in the loop, look what happened. water started spouting out of the stub cap. This told me 2 things:

1. exactly where the leak was - you can see the water shooting out of the top.
   
2. that there was only one leak-that was the only hole in the system until I open the spout and pressure was allowed to equalize
   

I have since cut off that cap and see now why it leaked. it is a black pipe cap on a copper thread and pipe. Electrolysis corroded a large hole right in it.


Now I am having a hard time because the loop is full of water and I cant unsweat the connections. there is a constant drip from the loop not from the boiler. all the shut offs are holding it is just water in the baseboard that is dribbling out. annoying because I cannot progress.

I am reluctant to take my air compressor to it will just spray me in the face. Would appreciate a strategy to blow the water out and avoid getting drenched.




You can see in this pic I cut away pipe.

john p_2

Not a big fan of it but here might be one of the best uses of it - Pro Press fittings to repair this...

NY_Rob

To prevent drips- a friend once recommended the old plumbers trick of wadding up a slice of wonder bread into a ball and shoving in into the pipe to prevent (non-pressure) drips for soldering. Once pressure is restored- flush out the dough ball.

Cut off the old fittings at the joint with a oscillating multi-tool, clean/prep old pipe, use a M-M coupling to extend if you need to and make all new bends, etc..

Replace that hose bib with a modern washerless ball valve.

ChasMan

I tried the bread trick once when I was really stuck and it did not work for me, had a whole slice in a piece of 3/4.. It just dissolved under heat. I think you need to use a hard roll and stuff it down in good with a screwdriver away from the heat a bit.

Ironman

I wouldn't recommend using bread on a closed loop. I've had it take over 3 days to come out of an open faucet.

If the copper is in good shape, using ProPress is your best solution. Many plumbing supplies will rent the tool.

If you can't get that, then for a home owner, I'd recommend cleaning the pipe thoroughly and using Sharkebites fittings until someone can do a more permanent repair.

ChasMan

That's the subtlest dig at sharkbites I have ever heard. That must have been some starchy bread. Scratch my hard roll idea then for sure. I hate to see copper replaced by PEX. Just be patient and boil it out or blow it out. A little water in the face never hurt anybody.. well, that's not true.

HVACNUT

Try using a wet vac with the purge drain valve open.

jjustinia11

So I used an air compressor and plastic elbow to blow all the water out of the loop. I cut into the junk pipe to make some room to pull and work and then unsweated 3 of the 4 connections points to get all the bad pipe out (amazing that someone used black pipe caps on the stubs) and I then used aluminum foil to keep the dirt off the work.

Last pic is finished product. holding 20PSI for the past 15 minutes after I bled the loop from the new ball valve spout. I put in other all ball valve cut offs, because you can never have too many ways to stop a leak and in case the others fail.

I still never found out what those stubs were there--they are not there anymore.

Ironman

Good job.

jjustinia11

Ironman said:

Good job.

Thanks! Any suggestions of what I can fill this hole other than concrete to protect the pipes and block water from coming up an in? I was thinking of maybe putting hydrolic cement under the pipes after digging down a bit more and just leaving the pipes exposed in case I need access again.

Thoughts?

Heat is working great and pressure is solid. I am going to swap out the pump with a grundfos. Spacing is the same and loop is small.

Ironman

If you insulate the pipes, it won't matter what's surrounding them. I'd do what you said and leave them accessible.

Shane_2

Nice Job.

Maybe armaflex around the pipes and fill with pee gravel?

jjustinia11

Shane said:

Nice Job.

Maybe armaflex around the pipes and fill with pee gravel?

good idea

Gonna also replace the pump. I am going to thread on a ball valve in front of the existing gate valve and remove the bottom gate valve. move everything over and isolate the pump with a ball valve. I won't use the gate valve on the boiler side anymore, but use it to avoid draining the boiler.

HVACNUT

Id like to exhume the installer and ask about those stubs too.
Nice job @jjustinia11!!

jjustinia11

HVACNUT said:

Id like to exhume the installer and ask about those stubs too.

Nice job @jjustinia11!!

Agreed! it was weird.

Do you see any problem leaving the gate valve on the top of the circ pump and threading in a ball valve right in front of it using the existing nipple? basically using the gate valve one last time to add the ball valve and then opening the gate valve one last time to never be turned again and using the ball valve in front of it till the end of time? Ignoring the space thing I will need to work out. I got some street 90 brass elbows that will keep things tight and I will take out the gate valve under the pump now that I have the ball valve below that one. So everything basically shifts out a couple inches. the gate valve may corrode in time and washer be useless but since I wont turn it to close flow it should be just a pass through-right??

I guess the real question is could that gate valve fail and leak if I never turn the knob again? just dont want to drain the boiler again.

nicholas bonham-carter

Maybe leaving this underfloor connection open with a cover over it would be a good idea.
We’re glad you solved the problem, and hope that if you see someone else here with a similar problem, you can guide them through the procedure you have performed. There may be other things you can learn from here to make sure your system is in top shape.—NBC

jjustinia11

nicholas bonham-carter said:

Maybe leaving this underfloor connection open with a cover over it would be a good idea.
We’re glad you solved the problem, and hope that if you see someone else here with a similar problem, you can guide them through the procedure you have performed. There may be other things you can learn from here to make sure your system is in top shape.—NBC

That is the main reason I take the pictures and show the end of the job, so others can follow and see the full resolution and see the steps I take with everyone's advice, instead of just taking the advice and disappearing.

HVACNUT

You've gone this far. Why not?
I would change the circ too.

jjustinia11

> @HVACNUT said:
> You've gone this far. Why not?
> I would change the circ too.

Pump and new fitting are on their way. So far the zone is operating great. Pressure in boiler is rock solid.