Please help identify this pipe/valve in my garage

[Mark.S]

Hello
Can someone help me identify this pipe/valve in my garage.
it’s near my water heater and I’d like to remove it to fit a sink in that area but it has pressure. Also the valve shown is corroded in position. Not sure if open or closed I put a wrench on it and almost snapped the stem.
many idea what it could be for ? I had something similar in my last laundry room again near my water heater. Thanks

 

[Jeff Handy]

What is behind that wall?

Is that outside behind there?

That valve might be a winter shutoff for a sillcock.

Or maybe there used to be a slop sink there?

I see a rubber cap, is that covering a functioning drain line?

 

[Jeff Handy]

I fixed your sideways picture.

 

[Mark.S]

Thanks for fixing the picture!
This is on an interior wall in my garage.
the other side of the wall is a half bathroom but the valve is not related to anything in there. I know this as we remodeled it recently.
there could have been a slop sink there before I’ve only been in the house 6 months.
it could be a shutoff for an external faucet The faucet is not immediately near this valve though and there are two other exterior faucets at the other end of the house.
Yes the capped drain is open and in fact I’m part way through plumbing my new sink into that drain.
here’s another pic with the wall open
Please let me know if you have any other ideas I wish I could shut the valve a test the outside faucet but not possible it’s so corroded

 

[Mark.S]

PS. The lines each side of the valve disappear up into the ceiling of the garage so tricky to say where they originate and where they are headed ...

 

[Mark.S]

 

[frodo]

I suspect. the loop is either a hot circ line that needs a pump
OR a water filter loop

You are going to blow lines to find out which
turn the valve on top of the water heater OFF
turn the valve OFF that is the loop , CUT the middle of the loop
turn the meter on
open the loop valve any water? if yes, that piping is cold water
if no the piping is hot water.
NEXT
open the valve on top of the water heater. do you have water at the loop?

if yes, it is a re circ line that is not hooked up
IF NO. It is a water filter loop

 

[Mark.S]

Thanks Frodo/McGyver !
The only issue I have is that the valve is corroded solid. I believe it’s open but not 100% sure.
I’d love It to be a recirc line as we have a looong wait for hot water at the farthest bathroom from the water heater.
maybe I’ll switch off the water, cut the lines and move them up the wall a couple of feet to make room for my new sink
I guess I could also replace the valve while I’m doing that and then run your test

 

[Mark.S]

PS. It’s a 3/4” valve/line size so probably related to a main supply line of some kind

 

[Copymutt]

Soak the valve w/ penetrating oil. Let it set and slowly work it.

 

[Jeff Handy]

As long as you are reworking that whole mystery pipe, take that crappy saddle valve off of there.
They often eventually leak, and usually don’t turn off when you need them to.
Pure garbage.
Install an actual valve, or you are just inviting a similar problem like you have now with that mystery valve.

 

[Mark.S]

Thanks everyone. I really appreciate the inputs. I’ll let you know if I find out anything else interesting

 

[Mark.S]

Hello again
Thanks to copymutt suggestion I let the valve soak with penetrating oil and after working it back and forth a bit I managed to determine that it was open.
so I closed it and checked the sillcock outside the garage. Still pressure there. Then I tried the hot and cold faucets in the bathroom. Hey ho. The answer.
there was zero flow from the hot supply.
Conclusion. It’s the main shutoff to all the hot water in the house. My water heater like many has a valve on the cold supply but nothing on the hot water side so I guess this is why that valve is installed. To make the hot system easier to isolate ?
So I’ll definitely not be capping this line. Ha ha

thanks again to all who offered their comments

 

[Rickyman]

Thanks Frodo/McGyver !
The only issue I have is that the valve is corroded solid. I believe it’s open but not 100% sure.
I’d love It to be a recirc line as we have a looong wait for hot water at the farthest bathroom from the water heater.
maybe I’ll switch off the water, cut the lines and move them up the wall a couple of feet to make room for my new sink
I guess I could also replace the valve while I’m doing that and then run your test

You have a Grundfos comfort system circ pump on top of the water heater. It’s either not plugged in or it’s failed. Fix that and you won’t have to wait a long time at the furthest fixture for hot water.

 

[Jeff Handy]

Good catch.

Looks like it has a clock timer on it, maybe the kind with little plastic pins that break or get lost.

 

[Mark.S]

Thanks guys. Yes you’re right. Well
Spotted !
Looks like The previous owner unplugged the pump and the temp recirc control valve was removed. It’s lying on top of the tank.
having been in the house 6 months I haven’t got to that yet but I definitely don’t want to recirc hot water in the cold water pipes so I’m not planning to install it under a sink and allow the (lukewarm) hot water to cross over into the cold
lines due to possible contamination and deposits from the hot tank including the sacrificial corrosion anode material Etc

 

[Mark.S]

Final note in case anyone is searching for similar info in future.
after further investigation this valve is upstream of the heater and basically seems to be an old/original shutoff valve for the cold water supply to the water heater.
At some later date a ball valve was installed right at the cold water inlet connection to the tank so this old stop valve and associated piping loop is now redundant as far as I can tell.
I’m going to remove the valve when I relocate the line