Hello. A few months back, we replaced a leaky (hot water) faucet in our basement sink. The only place we could figure to cut off the water flow was at the hot water tank. We have only been in the house for about 7 months and are still learning/trying to understand the mechanics, which in most cases appear to have been done by someone with little experience or concern. Anyway, once we turned the hot water back on, the flow to our shower upstairs was impaired. It wasn’t drastic, but enough to disappoint. At that time, I removed the shower head and cleaned it, figuring sediment had obstructed it. It helped a bit, but what I did notice then was that with the head removed, flow was full on cold, but decreased as the handle was turned to hot.

Recently we installed a dishwasher and a separate valve for it. This meant shutting the hot water tank off again. As you can guess, the same thing happened with our water pressure, only much worse this time. The shower has been hit the hardest, and there is also some pressure loss at the kitchen sink (hot water only, cold is fine in both). The bathroom and ½ bath sinks are fine. So what gives? Yes, I removed and cleaned heads/aerators, but it made little difference.

We thought perhaps the hot water valve on the tank could be the culprit, as it looks kind of corroded. But why are only 2 areas affected by pressure loss? Our tank is about 5 years old (gas), and we have city water. The house was built in 1928 and has a mix of old (galvanized) pipes and some copper.

We are fairly handy and willing to attempt, within our limits, to rectify the problem. At this point, I just want to narrow it down and get an idea of what may be occurring or if we can even handle it ourselves. I have read at least 40 + posts here and feel more confused than anything. Sorry if I provided too much info or not enough. Would be grateful for any suggestions. Will check back after taking a horrible shower! Thanks in advance.

Have you flushed you water heater? Do that and I think you are going to see some white debris flushed out, could be a deteriorated dip tube or just calcium. This stuff is likely getting caught in your mixing valves prior to your flushing the tank. Shut off your main and open a faucet to blow off pressure. Remove that new valve and inspect the inlet port for debris. Pick it clean with a tooth pick and flush it with water. Blow air through it with your mouth before trying to reinstall. If it is still clogged just come back here and any number of us can help.

Hello. Because I am a slow learner or just easily confused, I have to ask lots of questions, so please forgive me. No, we did not flush the water tank, yet. At the risk of sounding dumb, what do you mean by the “main”? The valve where water comes into the house (which is just below our water meter)? Also, when you say remove that new valve and inspect, are you referring to the new valve we just installed under the kitchen sink for the dishwasher? If so, I’m not quite sure what that has to do with the ultimate issue of pressure loss in shower. Thanks again.

I apologize for talking over your head, yes, you are correct, the main is the valve by the water meter. Your question about which valve got me thinking. If there is crud in your hot water that new dishwasher valve has likely picked up some of that same debris. It won't be very obvious because most of us turn the washer on and take off somewhere. If the washer doesn't appear to be a problem lets just ignore it for now. I think the valve inside your shower in plugged on the hot side. The valve is hidden inside the shower wall and covered up by a plate called an escutcheon. The handle goes on top of the escutcheon. Since you are new to this homeowner/plumbing stuff I will respectfully ask if you want to try a few more things or just call a licensed plumber. It is up to you but we do have plumbers here who can help you. What do you think girl?

Oh, thanks so much for replying again! You can't imagine how much searching I have done on this subject! I do understand now, the difference between flushing and draining a hot water tank!

We thought the main valve looked too old to mess with, but I gave it a turn yesterday, and it moved, so I think we can shut the water off there.

As for the dishwasher, which we have only used once, I'm not sure if I can detect a problem there, but cleaning out the valve should not be a problem and does seem like a good idea.

As for the shower, we have a single arm dial type (which by the way was installed, not by us, with the hot and cold reversed). It's supposed to go from cold to hot and does the opposite. This is the type of nonsense going on at this house. Anyway, we are willing to give this a shot. My boyfriend has already installed a pop up drain, the dishwasher, new outlets, a new circuit and many other things he had never done before. I am pretty handy too! So does it make sense to start from the top down, to check the valve in the shower before attempting to flush the tank? If so, I am game.

The shower handle/escutcheon is Moen, but not the shower head (that is Sloan). This is just a shower by the way, no tub. This stuff is probably about 10 years old, give or take. This is roughly when they (supposedly) remodeled the bathroom. I won't go off on that. I went to the Moen website, and it looks like the Monticello One Handle Shower Faucet with Standard Valve. I am going to attempt to attach a picture. http://i112.photobucket.com/albums/n181/srammacher/moen1.jpg

Thanks again for your help. I really appreciate it!
~Stacy~

It went into detail

Hey Stacy, good pic. I would suggest flushing the hot water tank now before we try to clear up the shower problem. There is probably more debris in the tank that could just plug up the valve again. Shut off the fuel, gas or electric , to the tank before you flush. Do you know how to flush the tank, you will need some garden hose to attach to the drain at the bottom of the tank. You can't see it in the pic but there is a small set screw on the larger base of the handle, back it out about one full turn and the handle should pull straight out. The escutcheon is held by two screws that will be apparent with the handle gone, remove both screws completely and pry the escutcheon off the valve and wall. There is usually some foam tape or silicone caulk behind the escutcheon that will try to hold it to the wall, might slide a steak knife back there if it doesn't come loose. Now you will see the plate that holds the cartridge in the valve body. Make sure your water main valve is shut off and open a sink faucet to blow off pressure. Remove the screws on the plate and the cartridge should pull straight out. Inspect the bottom side inlets and I think you'll find debris, just pick it clean with a tooth pick. Run some water onto the valve and blow air through it with your mouth. Before reassembling hold a towel over the open valve and have your boyfriend open and close the main letting it run for a minute to flush the lines. Let me know if anything isn't clear or you run into something unexpected. There is usually someone here who can help.

OK, one last comment/question. I thought for flushing the tank (different from draining according to speedball), you only needed to turn the flame down to pilot, as opposed to shutting gas off completely. There is conflicting information out there about this, and the owner's manual doesn't say much. I was hoping not to have to shut the gas off because it's the relighting part that scares me.

I guess it shouldn't take too long since the tank is not being emptied, only drained to a point where the water runs clear. The inlet should remain open (from what I have read at the manufacturers website)?

Lastly, the drain valve doesn't actually have a handle on it, only a groove that looks like you would insert a flat head screwdriver into (yes, picture to follow). Is this how it's supposed to be, and if so, how do you open it? Sorry if that sounds dumb. Thank you! PS: Will get to the shower part later.
http://i112.photobucket.com/albums/n181/srammacher/drvalve.jpg

Yep, setting the gas to pilot is OK. You are correct about a flat head screw driver and if that slips off too much vise grips or a channel lock plier may do the trick. Speedball1, if you are out there can you give us some more advice.
Thanks,
Bob