How Can This Happen???

JPV123

Here's a strange one... We are finishing a 3rd floor walk up attic in a house that's about 2 years old. The original builder roughed in the plumbing. The water supply lines came up about 16" and were capped. The drain/waste lines were in place. I had my plumber run the supply line to where we needed the for the toilet, sink and another sink for a wet bar. The lines were not hookeg into the plumbing they just terminated in the crawl space. My plumber tied the lines to the house plumbing in the crawl space. The next day I get a call from the homeowner saying that the kitchen sink has less pressure that it used to and the hot water changes temp when taking a shower. It gets very hot then gets cool and then warm then hot and doesn't stay constant. and before they used to put the faucet in the middle for hot water and know they have to turn it all the way to hot. We took a look and turned up the water heater and shut the shut off valves to the third floor but that didn't change anything. Could something be going on with the supply lines from the original builder in the wall? I can't imagine what we did would cause anything like this. I now told them to call in the original builder to see if he can find anything. Of course that means i have to pay the bill unless he finds something totally unrelated. Although the HO already said "I know he did something that's causing this". I may have to fix this even if it's something unrelated to what we did.

mdshunk

I don't have your answer, but this general thing happens to me all the time.

You fixed my porch light, but now the pump in my koi pond quit working...

You ran a new phone line through my office, and now the number '9' sticks on my adding machine...

You put on a new thermostat, and now I have to set room temperature at 72 degrees and I only had to set it on 60 before...

You installed a new receptacle in the kitchen, now channel '5' on the TV is fuzzy...

(these are all actual past customer complaints)

Double-A

As for the kitchen sink, check the aerator. It may have some debris in it.

On the shower, what brand and model is it? If it is an anti-scald model, the spool might have crud in it and isn't moving freely or the air in the system might be causing problems. If you think you have the hot and cold crossed, just turn off the cold water supply to the water heater and turn on the hot water at a 2 lever faucet. If you have constant flow, you have a bad shut off valve at the heater or a a crossed line.

As to turning up the water heater, turn it back down. If someone gets burned you're gonna take the fall for it. Don't ever jack up the temp on a water heater past 120 degrees with out installing a tempering valve that is set to 120 degrees.

Debris in the lines to the shower can also cause this to happen. The pressure balancing will make it go hot and cold as it adjusts.

If the shower valve is not a balancing or anti-scald model, then I would pull the dip tube on the water heater and check for damage or deterioration. A bad dip tube can cause hot to go cold fast and if gas, when it fires, cause it to go warm/hot again, but mostly it just goes and stays cold.

__________________
"My clients’ wishes are the center of my attention." -- David Guido, a contractor in Woodstock, N.Y.
New York Times, July 20, 2006

TimNJ

I would check for a crossed line too. If the lines were already roughed by the builder, who knows what his plumber may or may not have done when running the lines. I used to work on an AF Base and the plumbers would constantly cross lines on really long runs. Nothing like a self sanitizing urinal when you run a hot water line to it.

plumber jay

Double a what does the dip tube have to do with the temp of the tank?

Ron The Plumber

Brand of shower valve would be helpful right now.

ABLE1

I would guess the emphasis is on the word "past".

__________________
ABLE1

gitnerdun

Hey nice forum you have here, first round is on me.
I second the bad dip tube, seen a lot of those here. Check areators for fine white powdery stuff.

Ron The Plumber

Change in temps up and down like stated almost tells me a crossed line, if it was a dip tube, water would go from hot to luke warm in very little time, and not go from cold to hot, I agree turn off water heater valve and turn on a hot water faucet somewhere in house, if you have flow, you have a crossed line.

JPV123

It was because the Delta trim kit was not installed and the water was mixing at the shower body. Makes sense. I had to get a different plumber in to fiqure it out. Between that and a few other mess ups, needless to say, I'm currently looking for a new plumber.

Double-A

The dip tube directs water to the bottom of the tank, where it wants to be anyway, due to its higher density than the hot water at the top of the tank.

As it mixes with the other water in the tank at the bottom, this growing slug of cold water acts like a big piston to push all the hot out ahead of it as its level grows in the tank.

If the dip tube is damaged or missing, then the cold 'short circuits' to the hot side, providing a very short supply of hot water before it goes cold. Even its higher density won't allow it to settle to the bottom of the tank quickly enough to not be pulled to the hot water outlet of the tank 8" away.

If the dip tube was deteriorating from the bottom up, these symptoms would be unnoticeable for a long time, then become gradually noticeable then a full out problem with less and less hot water available.

As the cold enters the tank, its not at the bottom in the area where the thermostat is if its short circuiting to the hot side and exiting, so the t/stat doesn't see a big enough drop in tank temperature.

Also, the water in the bottom of the tank is still close to target temperature and isn't cold/warm as would be expected when the burner fires.

When the burner does fire, this water will become heated enough to make its way to the top of the tank and temper some of the cold water.

This hot water will be much hotter than the target temp for the tank, so when it does temper that cold, it can raise its temp up to 106 degrees (shower temperature) or so, and hence, provide hot water for a short time again, until the convection in the tank (hot water moving up, cold going down, or trying to anyway) cools the temp of the tank down and tempers all the water in it.

So the water goes 'cold' again, as this super hot water is not super hot anymore, as the entire tank is cooling off and trying to act normally again.

This 'overheating' of water can happen in properly operating water heaters, set to 120 degrees, with good dip tubes as well. If you've showered behind someone and the water heater is firing, you might notice you use less hot water than if you were the first one into the shower that morning.

Sorry for the long water heater lesson, but a gas water heater can play havoc with temperature balancing shower valve. This is why I advocate tempering valves on water heaters and why they are required on most model codes for commercial applications.

__________________
"My clients’ wishes are the center of my attention." -- David Guido, a contractor in Woodstock, N.Y.
New York Times, July 20, 2006

Double-A

So your new plumber said that the valve was causing the low pressure at the kitchen sink and was not holding a set temperature because the trim kit was not installed?

__________________
"My clients’ wishes are the center of my attention." -- David Guido, a contractor in Woodstock, N.Y.
New York Times, July 20, 2006

plumber jay

double a
Thank you for the explanation.
I was thinking you were talking about the sacraficial anode.

If the dip tube is in fact the problem a possible fix would be to cap of the top connection and connect to the bottom of the tank. Provided you have a spot for this. You could probably take the hose bibb of and put a tee in then reconect the hose bibb and your cold water supply.

JPV123

Yes, as soon as the trim kit came in we installed it and everything went back to normal.

Double-A

I've never heard of a trim kit causing so much trouble. What was the model of Delta valve you used? Do you a pic of it?

__________________
"My clients’ wishes are the center of my attention." -- David Guido, a contractor in Woodstock, N.Y.
New York Times, July 20, 2006

gitnerdun

If the valve was a non-pressure balance valve, I can see how it could cross the lines if the shower and spout were capped off and the valve was in the open position.

plumber jay

yes this would be the only way. And even if to affect the sink on the first floor? it could but.......