We had our shower installed a few months ago.  Wife has mentioned since then that the hot water comes out as soon as the sink faucet is opened.  There is no "recirculation" stuff.  My overactive mind is trying to figure out why the water is hot as if it has been running a while.

The jackass shower installer had an extra hard time from hitting the hot water line with a jack-hammer.  They had trouble cutting back to good pipe, and used a bunch of PexB connections. Everything was supposed to be OK.  They back filled around the shower drain and lines with dirt...THEN poured a bucket of concrete over the whole mess.  Then installed the shower pan and walls.  I know I'm fucked...

Still trying to get the company to fix shitty caulking, then this Hot water issue came up.

Not sure how to verify if there is a leak in the hot water line.  Any fucking around will involve major hassle like pulling the 60 in. vanity and sink.  House is on concrete slab.

Any thoughts?

Paladin

Check pressure at kitchen sink, then bathroom sink and shower to determine if there's a difference?

Shut off all faucets then look at meter and take a reading. Don't use any water for an hour (no flushing toilet etc), then take another reading, if it's not the same you have a leak. To keep water hot any possible leak should dump at least a gallon of water in an hour. Even better would be to leave the house for 4-8 hours, taking readings before you leave and right after you return.

When I had a leak in the slab, the floor was always warm where the leak was.  I would start there.

There are a lot of red flags here. Your water lines, in the best of circumstances, shouldn't be in direct contact with the concrete or earth. The mention of multiple pex connections is concerning. It should look more like this:

Attached File


That's not always done but it allows for repair/replace broken lines without joints under concrete.

If you do find a leak, you may need to lawyer up. It sounds like your repair is under the shower and will require completely removing and redoing it. If there's no conduit to chase the pex, you still have a potential for problems with a joint you can't get to.

The original lines were copper, in or under the slab.  After damaging the hot copper pipe, the installer had trouble with the copper to pex junction and cut it back several times.  No torch involved, guessing some kind of compression fitting.

The other side of the cut pipe needed the same copper/pex junction.  And the first time they said the cut pipe was fixed, it started leaking before he got in his truck.  Installer no longer employed there.

Phone calls made, now we wait.

Paladin

Maybe a plumber will be along to straighten me out if I'm wrong (my history is project management and carpentry) but I'm not aware of a copper to pex union that doesn't need to be sweat aside from a shark bite. I would NEVER put a shark bite fitting in a place that can't be accessed. I'm told they have great longevity. I've also seen them leak more than I can count. When I redid my house, I did pex and cut the copper below the floor because I didn't want to dick with the finished space. I sweat copper to pex unions and never looked back. Hopefully your contractor did the same and there's some other reason your hot water is weird.

Got thermal? or digital contact-less thermometer? Check the floor area for temperature differences.

As stated above, once you verify you have a leak by looking at the meter, verify its the hot water by shutting off the water inlet to the water heater and repeat the verification. If the meter stays the same, you've confirmed its the suspected hot water line.
Good luck!

So pex inside of PVC is the new standard?

IDK about new. If it wasn't radiant heat embedded in the slab, it all went in conduit 15ish years ago, at least on the projects I worked. They were architect specified but different architects from different companies called for similar design.

Do you have a single handle faucet or valve that is leaking through acting like a circulating loop?

Once i was concerned about how quick my shower water became hot. So I timed it one morning - 12 seconds.  Then at night I turned the valve off AT my water heater. This way the water in the pipes would cool overnight. In the morning I turned the valve on and immediately turned on the shower - again timing, it was 12 seconds again. It eased my mind.

Later on an unrelated mission I was under the house and verified it's dry as can be.

The shower faucet is a Delta.  Has a lever for temp, and a lever for volume(?).

Paladin

eta: ended up turning off power to the water heater, otherwise seems to be on constantly.  need to fight with the wh cold water inlet faucet so I can shut off the hot water leak.

ETA: finally figured out the smart meter has a display to show usage rate. 0.08 gpm x 60 = 4.8 gals per hour with all water usage stopped.

That seems like a pretty big leak. Did you turn off the power to the water heater just to save electricity? I'd just turn off the cold water supply to the heater (seems like maybe you're looking into that?). It would leave you with no running hot water, but you could turn it on minutes per day to get a quick shower until you get the leak sorted. This would minimize leaking.

We installed a shut-off for the water heater inlet.  No wasted water except while showering.  I can leave the breakers alone!  I can leave my house water (mostly) on.

My new shower, is going to be even newer.  Their district manager came over, decided to rip it all out, excavate whatever is leaking, and reinstall with new material everywhere.  The guy who installed my mess was fired shortly after doing my shower.  He was four hours into the job when he jackhammered my hot water line, and things went down the drain from there.

Paladin

ETA: Shower reinstall is almost complete.  Waiting for the caulk to dry.  New guy they sent did a great job.