hot water cools fast

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If you don't have the original documentation that came with that faucet, you can contact Moen on their web site and find out the name and phone number of the sales rep or agency that handles Moen in your area. E-mail that rep or agency the picture of your faucet, and they should be able to provide you with a photocopy of the original documentation. Alternatively, if the sales rep or agency can provide the model number of the faucet, you may be able to download it from Moen's web site. That documentation will explain how to recalibrate the antiscald mechanism on the shower faucet.

Redwood:
What do you think of the idea of running the shower until the water cools off, and then, with the shower still running, open the nearby bathroom sink faucet and see if the water mix can be made to run hotter in the sink than in the shower. That would determine whether the problem is in the shower faucet, or in the hot water itself.
 
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I think you may be onto the problem.
If it is a pressure balancing valve the pressure balancing valve may be stuck too far to one side favoring the cold water.
The lav could also be a factor but turning it off will isolate it from the mix without muddying our diagnostic efforts.
 
If you don't have the original documentation that came with that faucet, you could probably e-mail the sales agency handling Moen in your area that picture, and they could provide you with a photocopy of the original documentation. Alternatively, if the sales agency can provide the model number of the faucet, you may be able to download it from Moen's web site.

It is even easier than that Nestor...

All he needs to do is visit this link and answer a few questions and Moen will show him pictures of a few faucets and he gets to pick his out of the line up...
Replacement Parts

Moen has by far the easiest website there is to find your parts diagram.
 
OK, so I'll shut off the Moen sink faucet and try the shower to see if temperature improves. If it does not, I will need to look at shower faucet and possibly adjust the pressure balancing valve, right? Are you saying that adjusting it may fix both the temperature and the pressure problem? And so if shutting of the sink faucet fixes the temperature, then I can still try to adjust the shower valve to improve pressure, correct?
Thanks.
 
Lets just try the shutting off the sink and see if the temperature improves for now. I'm for keeping this simple...:cool:

But you can try looking up the shower valve and let us know what you have.
 
I was able to shut off cold water to the sink. I could not, however, shut off hot water completely. Even using an adjustable wrench, I could shut it off almost entirely so that when I pulled out the handle, there was a small trickle. Anyway, afterwards I took a shower. It seems that temp did not drop as fast as it did before, but I think it still dropped. Also, I am not sure whether it was because I shut off the sink faucet or because in the past I was using the shower shortly after someone else in the family did. By the way, I don't know whether it makes any difference, but the sink faucet is in the downstairs bath while the shower is in an upstairs bath. I am thinking about buying a water thermometer and measuring temp drop more accurately. But I don't think the problem has been solved.

I dug up the manual for the shower valve. It's Moen L82691. The install manual (http://www.moen.com/shared/pdf/instruction_sheets/ins898d.pdf) shows a temp limit part but I don't see any parts that control pressure. Also the spec sheet (http://www.moen.com/shared/pdf/l82691sp.pdf) states that "Showerhead is limited to 2.5 gpm (9.5 L/min)". Is this a lot compared, say, to an average valve made 10-15-20 years ago? I am asking because I am wondering if we are out of luck trying to increase water pressure.
 
Okay your valve is a Moen Posi-Temp which uses the #1222 cartridge and has the pressure balancing built into the cartridge. To check the pressure balancing you shut off the water and remove the cartridge. when you shake the cartridge you should hear the pressure balancing rattle back and forth. If it doesn't usually taking the cartridge and giving it a sharp rap on the floor or , counter will free it up. This can cause both temperature and pressure problems.

Knowing if the temp is dropping at the utility sink when the shower cools off would be a big help...
 
Lets back up a bit and get real numbers with a thermometer and time measured.
These "I thinks" are starting to make me wish I was there...:eek:

Also when the shower cools off... Has the output of the water heater cooled off?
 
Also when the shower cools off... Has the output of the water heater cooled off?

How would he determine that? By running the hot water faucet in the utility sink near the water heater?
 
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Thats what I would do Nestor...

I don't think we have answers coming...:rolleyes:
 
(Prolly another case of alien abduction.)

In which case, if the water at the utility sink is hotter, then we suspect the pressure balancing mechanism in the cartridge.

But, if it's the same temperature, then I'd shut off the water supply to the heater and allow water to drain out of it. If the water in the heater is the same temperature as the shower and utility sink, then we've simply run out of hot water. But, if it's hotter than the shower and utility sink, then it's time to revisit the dip tube, correct?
 
Thats what I would do Nestor...

I don't think we have answers coming...:rolleyes:

They are not coming since I can't find a good thermometer. That is, one that has a good degree range, a fine scale (1 deg as opposed 5 deg) and waterproof. I checked my local stores plus Amazon but did not yet find one that seems right.
 
If you send me a self addressed stamped padded envelope, I'll send you one of these.

071.gif


It's a Tekmar 071 universal temperature sensor. It's a thermistor. It changes it's resistance very precisely with changes in it's temperature. You simply measure the resistance across it, and you enter that resistance in the chart on page 3 of this PDF file, and read off the temperature.

http://www.tekmarcontrols.com/literature/acrobat/d070.pdf

I replaced it hoping that one of the problems with my boiler was due to a faulty sensor, but it turns out the old sensor was OK. So, I replaced a good sensor with a new sensor, so I have a good sensor I don't need.

You can guestimate the temperature to + or - 1 degree F using the chart just by eyeballing based on the resistance, but you can also mathematically interpolate between resistance readings to get a much more accurate temperature reading (to well within one degree F). Thermistors, by nature, are very accurate, but the accuracy with which you measure the resistance will probably be a limitation here.

To overcome that limitation, you might just work in ohm rather than degrees, knowing that higher resistances mean cooler temperatures. After all, you don't need to know the temperature precisely, you just need to know if the water coming out one faucet is significantly hotter than the water coming out another.

Use a pair of wire nuts to connect the leads of the thermistor to the probles of your digital multimeter, hold the thermistor by the leads with the sensor bulb immersed in the water and wait for the resistance reading to stabilize. Then, convert that resistance reading to a temperature.

It's good from -60 deg. F to 255 deg. F and at room temperature (25 deg C), it's got an accuracy of 0.2 deg. C or about 1/3 of a degree F. The sensor bulb is metal and it appears to be well sealed, so I don't think immersion in water would harm it.

http://www.tekmarcontrols.com/prod/071.shtml

Private Message me to get my mailing address. Make sure to send a PADDED envelope since the hard metal sensor bulb is 3/8 inch in diameter and 3/4 inch long. I'd be concerned that putting that in a normal paper envelope would cause the envelope to tear in the mail sorting machines. A padded envelope would work a lot better.
 
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Ilyaz:
Let me know if you didn't get my mailing address. That was the first time I sent a personal message rather than just reply to one.
 
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