On county water supply. Have gas hot water heater. Three weeks ago wife noticed water pressure had dropped–she noticed while taking a shower. Took about a week for me to notice the same thing (also while showering). But the issue seemed contained to this shower.
Pulled the shower head off, everything looks kosher. Pulled the T-valve off, and discovered the original shower head rubber washer (water-saver?) had split into two ring, and one part was tumbling freely in the shower neck. Removed it, put everything back together and no change.
Lived with this another week and this morning I noticed the pressure dropped off at the kitchen sink. Morning routine is to use hot faucet at kitchen sink and get water for coffee pot. The pressure dropped off after maybe 3 seconds.
Went about my business, made the coffee, went to rinse the pot out and had lots of pressure … initially. Then the pressure dropped off again. And likewise, this was from the hot water tap. I am now wondering if this is a problem in the hot water tank.
The hot water tank has this gallon-sized milk jug inverted and attached to the HW tank. I thought that maybe this was a pressure regulator for what water expands during the cold-to-hot water heating cycle. Not sure if it can affect whatever we are experiencing or observing.
Ideas? Seems like most plumbers in my area have evaporated. Emailed and called (left message) with 5-6 last week and got no replies.
Replies
You have to determine if the loss of pressure is confined to the hot side only.
You have to know your incomming pressure.
Do you have a PRV on your incomming water line?
Your expansion tank on the water heater has nothing to with your loss of pressure, thats there to take up the expansion of the hot water when heated. A little more information and we can help.
The "milk jug" is an
The "milk jug" is an expansion tank. It would have no effect on the pressure while the water is running. The problems you describe are most consistent with a malfunctioning pressure reducing valve on your incoming water supply.
I do have a pressure reducing valve. It had been untouched for years until the basement plumbing rough-in took place. I cannot say it was even touched then. Might have, but that was months back (last Spring) and the problem recent. I need a flow-meter device. :)
There is a way that the expansion tank could be involved, if it's installed on the hot piping.
The outlet of the WH, which is typically a galvanized nipple, can become nearly blocked off with corrosion buildup. If the exp. tank is located on the HOT side of the WH, then the exp. tank becomes a small reservoir of hot water that is fed by the restricted WH outlet.
The volume of water in the exp. tank allows good flow for a short time as the compressed air in the tank pushes it out. This is similar to what a large pressure tank does on a well system.
If this is happening, the fix is simple: replace the hot outlet nipple on the WH.
For What It's Worth:
>>Morning routine is to use hot faucet at kitchen sink and get water for coffee pot.
Cook types will tell you to not draw hot water for making coffee. I believe the idea is that the buildup in minerals in hot water tanks screws up the flavor.
Actually, my doing this really isn't to get the coffe hot faster, but to get the hot water tank to fire up in the morning so that when I take a shower 30-60 minutes later I have hot water and not warm water.
Back to the PRV thing ... someone suggested I test the PRV. He said to loosen the lock nut and then turn the PRV screw one full turn (360º) clockwise--he noted the counter-intuitive nature of the PRV.
I was warned to not turn it 2-3 turns as it might pop opon some faucets and I'd have water running out. Ok, so I loosen the lock nut (turn it which direction?), turn it clockwise one full circle, reset lock nut and see if pressure has returned.
Now, last Summer I just finished the basement. Yep, 1250 SqFt of finished basement that is all drywalled, trimmed, and painted--ceilings, too. And guess what the drywallers didn't do? Leave an opening for the PRV. They left openings for the water cutoff to the house, and access to the sewer main, but that is it.
Ok, so I need to buy a holesaw, make an opening, see what kind of tool I'll need to adjust the PRV screw, and then I can test. The head of the PRV screw* feels square in share with no slots in it for screwdriver.
* The PRV is about 8-10" above the main water cutoff knob, which means the new opening in the drywall will be the same amount above.
Providing access to the PRV is always good, but your description of the problem you're having doesn't jive with PRV troubles.
You indicated that the pressure loss is on the hot side only, and that you get good pressure for a short time, but then it cuts back. Low pressure from the PRV would show up on both the hot and cold.
The only explanation I can think of that would cover your description of what's happening is the one I gave in my first reply.
In addition to the restricted hot outlet that I mentioned, any restriction that cuts down on the flow to the WH itlself would have the same effect.
Some water heaters have a built in back-flow preventer(on the supply side) - could that be the source of the problem here?
Yes, my original description was that this was on the hot side. Bare in mind that when I start the shower I throw the lever all the way to the hottest side, because I am trying to get that hot water supply line to dump its cold water first and then I adjust it accordingly.
Same thing with the kitchen faucet. I am deliberately hitting the hot water tap to fill the coffee pot in the morning, because 30-60 minutes after my morning brew I'll take a shower. By removing warm water from the HW tank, I am forcing it to kick on and I know I'll get nice hot water in the shower (after dumping the cold in the HW line) instead of warm.
Would you believe I do not have any means to track time to the second? I need a stop watch. I want to measure the time it takes to fill 2-gallon bucket when using just the cold or just the hot taps.
38 PSI. That is the pressure measured from the shower T-valve and also the kitchen sink.
That's on the low side, but still "normal". I generally figure about 30-65 as the acceptable range, and would shoot for 50 if I had control of things (with a PRV, for instance).
While reading the pressure in one place you should run a tap full bore elsewhere in the house and see how low the pressure drops. I wouldn't want to see it go below 25.