Plumbing mystery

flyingcheesehead

flyingcheesehead

Taxi to Parking
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Feb 23, 2005
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UQACY, WI
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iMooniac
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KUES/KMKE
So I just moved into a new-to-me house, built in 1988, and I can't figure this one out - The shower in the master bathroom seems to have a mind of its own when it comes to temperature. (I haven't used the other fixtures enough to know if this affects all of them or not.)

Basically, I turn the water all the way to hot to get the hot water up to the shower. Then, I adjust the temp down to a tolerable warm level. After 3-5 minutes, the water suddenly gets cool (not cold, but not something you want to stand in particularly long either).

If you do nothing, it stays at the cool temperature. If you change it to hot, after a few seconds it gets hot, and if you then adjust it to right back where it was, it goes back to the nice warm temperature where you originally had it set, and it stays there for another 15+ minutes, at which point the cycle can start over.

What gives? :dunno:
 
Single lever water control I assume? If so, the seals on the inside of the hot side are swelling or changing shape and cutting down the hot water. Or, if you have a demand hot water supply, there isn't enough pressure to keep the hot water heat on constant. Or, if you have a small tank, and you take long showers, you may be using up all the heat, then the tank starts it's heat cycle and you get more. A 15 minute shower is plenty of time to get clean, pull your pud, clean up again, think about Megan Fox, pull your pud again......
 
flyingcheesehead said:
So I just moved into a new-to-me house, built in 1988, and I can't figure this one out - The shower in the master bathroom seems to have a mind of its own when it comes to temperature. (I haven't used the other fixtures enough to know if this affects all of them or not.)

Basically, I turn the water all the way to hot to get the hot water up to the shower. Then, I adjust the temp down to a tolerable warm level. After 3-5 minutes, the water suddenly gets cool (not cold, but not something you want to stand in particularly long either).

If you do nothing, it stays at the cool temperature. If you change it to hot, after a few seconds it gets hot, and if you then adjust it to right back where it was, it goes back to the nice warm temperature where you originally had it set, and it stays there for another 15+ minutes, at which point the cycle can start over.

What gives? :dunno:
Click to expand...

Sounds like the water heater is tanking. Turn on the hot only and see if it goes cold. Or warm. Are the other faucets acting the same way?
 
nothing is wrong with your shower - obviously you should only take 3 minute showers
 
Matthew said:
Cartridge going bad?
Click to expand...

Ummm... What's that? :redface:

docmirror said:
Single lever water control I assume?
Click to expand...

Yup. And it's "backwards" - You turn it to the right to turn it on/hotter and to the left for colder/off.

If so, the seals on the inside of the hot side are swelling or changing shape and cutting down the hot water.
Click to expand...

Would they change back when more hot water was flowing though? If that's possible, this sounds like the most plausible explanation so far. How hard are those to change out?

Or, if you have a demand hot water supply, there isn't enough pressure to keep the hot water heat on constant.
Click to expand...

Nope, plain old tanked water heater in the basement.

Or, if you have a small tank, and you take long showers, you may be using up all the heat, then the tank starts it's heat cycle and you get more.
Click to expand...

Not that either, since it will go right to hot after moving the control to the hot side and it goes cool after only 3-5 minutes of use in the morning.

A 15 minute shower is plenty of time to get clean, pull your pud, clean up again, think about Megan Fox, pull your pud again......
Click to expand...

Hah! Well, I only ran it as long as I did for testing purposes - I wanted to see if it would happen again after the initial fix.

CTLSi said:
Sounds like the water heater is tanking. Turn on the hot only and see if it goes cold. Or warm. Are the other faucets acting the same way?
Click to expand...

Dunno on either count - Haven't had time or inclination to test it out more thoroughly yet. Maybe I'll use the other shower tomorrow morning.
 
Alrighty then, I will sound like a broken record. Turn off your water at the meter/street main. Take off the knob/handle, and inside you will prolly see a tapered beauty ring, or other chrome flange, may be held on by a set screw, or it may just spin off on its own. Once you get the beauty ring off, you should see a large slender gland nut. Turn that and it will remove the entire cartridge asm on most single lever shower deals. Some have a two flat gland fitting, some have a hex. Don't take the outer nut off, that's just the packing nut seal.

Once you have the cartridge in your hand, and water has drained back out of the lines, take it to your friendly ACE hardware store, and they will dig around and find you all the seals you need to restore it. When you put it back in, use a fair amount of vaseline or other light grease to insure everything stays put, and works smoothly.
 
The cartridge is the thing he pulls out around 2:56
Change that, It is a cheap easy fix.

 
SixPapaCharlie said:
The cartridge is the thing he pulls out around 2:56
Change that, It is a cheap easy fix.

Click to expand...
I haven't looked at the video, but I know what's in it.

Yeah, that's what I was referring to as "cartridge".

It's a self contained valve. Plus, it goes in one of two ways - the right way, and the wrong way. If you get it in the wrong way, you'll end up with hot/cold reversed.

It's a very simple job, I've done it several times.
 
flyingcheesehead said:
Yup. And it's "backwards" - You turn it to the right to turn it on/hotter and to the left for colder/off.
Click to expand...

Bingo, I assume you mean that if you turn it toward the H it gets colder and toward the C it gets hotter. If so, it's connected wrong and needs to be reconnected correctly.

If not, and it is properly hooked up, then replace the cartridge.
 
PaulS said:
Bingo, I assume you mean that if you turn it toward the H it gets colder and toward the C it gets hotter. If so, it's connected wrong and needs to be reconnected correctly.

If not, and it is properly hooked up, then replace the cartridge.
Click to expand...

The cartridge orientation can affect the H/C output.

On the Moens that I've replaced, I am pretty sure the cartridge will be keyed so it can only go in one way. In the center of the cartridge is a valve stem. The valve stem will rotate 360 deg. If H/C are reversed, simply rotate the valve stem 180 deg and reinstall the handle.

Go to step #8:

http://www.moen.com/consumer-support/installation-help/tutorial?id=moen0133
 
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Probably a cartridge.

Any chance the valve has an anti-scald device?
 
Looking like the cartridge is the culprit. No problems with either the kitchen sink or the other shower, so it's not the water heater.

Looks like I have a new project to add to the list!
 
flyingcheesehead said:
Looking like the cartridge is the culprit. No problems with either the kitchen sink or the other shower, so it's not the water heater.

Looks like I have a new project to add to the list!
Click to expand...
Worst part about swapping out an old cartridge is that sometimes they get stuck because of hard water deposits or other corrosion and don't pull out easily. I think they come with a little tool that helps you remove and reseat. But work slowly and try not to force anything. Shouldn't take too long, and it will feel brand new - because it is.

You might need to remove the escutcheon plate around the faucet handle (maybe not - I can't remember) so be ready to get a small tube of good caulk.

Those cartridges are really pretty neat inside. There are a couple of different paths that the H/C water can make depending on what side is open and closed. O-rings inside do all the work. If one of those o-rings has become unseated or cracked, I can see where you'd get an odd mixture of H/C. But to get the H/C swapped completely, you just have to turn the inner valve stem 180deg.
 
The water tank has a drop tube in it that takes the incoming cold water to the bottom of the tank, letting only hot water out the top. That drop tube sometimes breaks or corrodes off and falls into the tank. Start your shower, get hot water, then the cold incoming water starts chilling the hot water and you have to make adjustments to get it tolerable.

The tube can be replaced by removing the inlet fitting. A new one just drops in.

Dan
 
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