Inconsistent temperatures

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ar110

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My shower's temperature is really getting out of control. When I start the shower it is now almost
impossible to get the exact hot water temperature I have been using for years.

The water is either scalding hot, luke warm, or cold; there is no usable hot.

After the shower runs for a while the temperature I am looking for finally becomes available. Later
the temperature seems to change by itself and I then have to constantly readjust the temperature. I am assuming that change is due in part to less hot water in the water heater. One solution that has
been working for a while has been to almost completely shut off the cold water valve in the shower.
Doing so has, surprisingly, allowed for a wider range of temperatures. That fix seems to be working
less often, however, it is still working better than setting the cold and hot water valves at equal
levels. I have my water heater turned up to around 145 degrees, so when this began I thought
maybe that has something to do with it but I seriously doubt it because turning down the cold water
valve in the shower seems to have helped. We also do not have any thermostatic valves installed
anywhere.

The problem also occurs intermittently around the rest of the home (kitchen and bathroom faucets).
Also, it takes quite a while for the hot water to come through kitchen and bathroom faucets. Anyone
run into this problem before? Any fixes?
 
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ar110

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The water heater is a 38 gallon A.O. Smith Model E6-40L45dvb 110. There is a panel on the front of the water heater where you can set the maximum temperature.
 

fixitron

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The water heater should have a mixing valve to bring the temperature down to about 120 degF (or just turn the aquastat down- but let's not get into the absurdity of that code here). If you are also getting scalding water at other faucets, then turn down the aquastat or replace the mixing valve.
The other possibility is that the pressure/temperature balance in the shower valve is getting gunked up or wearing out. When you close down the cold water supply, typically a shuttlecock slides over to close down the hot to balance it. The shower valve likely has a cartridge,, so just replace that cartridge.
 

Diehard

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The fact that "The problem also occurs intermittently around the rest of the home (kitchen and bathroom faucets).", it almost sounds like the water heater is not controlling the water temperature very well. There could be a number of reasons this could happen. You can Google it for trouble shooting guides or prior to actual trouble shooting, to pinpoint the problem, you could try monitoring the actual hot water temperature fluctuations when flowing through a single hot water fixture, where no mixing takes place.
 

frodo

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right here right now, over there later on.
sounds to me like the scald guard on the shower valve is bad or needs adjustment

pull the handle and chrome thingy off the front of the shower valve
looky see if it has an adjustment
yours might look like this or is plastic, or round and looks like a gear

turn to the left is colder [counter clockwise]

scald_guard.png

we will deal with the intermittent issue after the shower issue
edited....turn off the water first
 

Diehard

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I would think the fluctuating water temperature issue should be resolved prior to fiddling with adjustments on the shower valve.
 

fixitron

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sounds to me like the scald guard on the shower valve is bad or needs adjustment

pull the handle and chrome thingy off the front of the shower valve
looky see if it has an adjustment
yours might look like this or is plastic, or round and looks like a gear

turn to the left is colder [counter clockwise]

View attachment 20528

we will deal with the intermittent issue after the shower issue
edited....turn off the water first
But that adjustment is only a stop to keep the handle from turning to a hotter mix of Hot & Cold water. It does not control the water temperature or pressure.
 

frodo

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But that adjustment is only a stop to keep the handle from turning to a hotter mix of Hot & Cold water. It does not control the water temperature or pressure.
the op said he changed the water heater setting, so he needs to re calibrate the shower valve
he also said he jacked up the water heater to 145 temp...this will harm the shower valve over 110

Pressure Balanced Valves
Pressure balanced valves are the least expensive and easiest anti-scald valves to make. In this design, a piston or diaphragm is installed in the faucet and responds to changes in water pressure. If the cold water pressure drops for any reason, the piston moves into position to limit the amount of hot water that can flow through the faucet. This type of valve must be recalibrated if the temperature on the hot water heater is changed at any point after the anti-scald valve is installed.



Thermostatic Mixing Valves
While more expensive than a pressure balanced valve, thermostatic mixing valves, or TMVs, need not be recalibrated or adjusted to accommodate changes in the water heater setting. TMVs mix hot and cold water in a chamber before it is allowed to flow through the faucet. This chamber contains a thermostat element that expands and contracts as the water temperature changes. An increase in temperature expands the element, blocking the hot water inlet to limit the amount allowed into the mixing chamber.
 

phishfood

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You have an issue where water is crossing over between the hot and cold water system somewhere. This usually happens at shower valves or single handle faucets. You need to figure out where this is happening.
 

ar110

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sounds to me like the scald guard on the shower valve is bad or needs adjustment
pull the handle and chrome thingy off the front of the shower valve
looky see if it has an adjustment
yours might look like this or is plastic, or round and looks like a gear
turn to the left is colder [counter clockwise]
View attachment 20528
we will deal with the intermittent issue after the shower issue
edited....turn off the water first
I've tried adjusting it only makes the water cooler and, oddly enough, less manageable.

You have an issue where water is crossing over between the hot and cold water system somewhere. This usually happens at shower valves or single handle faucets. You need to figure out where this is happening.
I've found the problem with fluctuating temperatures at numerous faucets, including double handled faucets.
 

ar110

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One thing I've recently discovered is that the hottest temperature recorded at any faucet is about 120 degrees. My water heater is set to 145 degrees. I live in a condo and have seen no evidence of the existence of a thermostatic mixing valve set to 120 degrees. I think that if I can solve this mystery all the other problems would be solved as well.
 

RenewDave

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Is your water heater a 40 gallon low boy? And how old is it? You said that you adjusted your temperature setting under a panel, your water heater has 2 temperature thermostats. You need to adjust both or your going to have trouble. 145 is just asking for trouble. Change out both thermostats (upper and lower) set them to 120 and see how it works. Then you’ll know if the shower actually has issues
 
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