I had water heater I bought from Home Depot installed on 02/05/2024. The water is not hot enough. Comes out at 115. I have both thermostats set to 125. I have to turn the upper one to about 135 to get it to kick in then can turn it back down to 125. Water than comes out around 125 after it heats. Next time go to use it and same thing, The upper thermostat does not seem to turn on when it should. Thanks for any help.
NEW Rheem WATER Heater not hot enough
- Thread starter briantro
- Start date
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So leave them at 135 if it heats to 125 at that setting. They’re not perfectly calibrated.
If I leave at 135 water will go to 135. I will try leaving at 135 and check later to see where its at. Its like the range is to big.
Make sure the thermostats are tight to the tank. Turn power off first.
Set them at 130 and leave it alone until you’ve had a few showers and the water heaters thermostats have been satisfied.
Check the temp by popping the relief valve into a bucket and checking the temp there. Make sure your thermometer is accurate.
Check the temp by popping the relief valve into a bucket and checking the temp there. Make sure your thermometer is accurate.
To check your thermometer.
Fill a glass with ice water. After a few minutes your thermometer should read about 34-35 degrees.
Fill a glass with ice water. After a few minutes your thermometer should read about 34-35 degrees.
Thanks. I do keep them calibrated. Boy that 135 is hot. I will set them both to 130 and go from there. The installer plumbed the relief to the back where I cant get to it.
Its running about 122 now. I will call that good. Thanks.
Where does the relief discharge end at. It needs to be visible
I just registered on here to post a near identicle question.
Plumbers just installed a new 50 gal Rheem water heater on 2/12/2024 ( model XE50T06ST45U1). Both thermostats set to about 120° from factory. I upped to 125° however temp at tap and shower was only about 122° and drops a good 10°-15° after only 15 gallons of use (7min shower).
I increased upper/lower thermostats to 130° and instead of increasing my temp, the temp dropped to about 118°. I found today the only solution was to turn the thermostats up to above 140° until I hear the click of the top element energizing and then back down and now I get the correct temp out of my tap/shower. I have it set to about 135° and hitting 130° on my calibrated thermometer.
I will check after family showers tonight and see if the temp reaches back to 130°. I grabbed my multimeter this morning, ensured I get full 240v, and I validated the upper/lower elements are alternating appropriately as if the thermostats are perfectly fine. I get about 12.4ohms of resistance from elements as well so those seem good. Seems parts all appear to be fine and the issue is just the thermostat not properly switching on when it should. Very aggravating for a brand new unit.
Plumbers just installed a new 50 gal Rheem water heater on 2/12/2024 ( model XE50T06ST45U1). Both thermostats set to about 120° from factory. I upped to 125° however temp at tap and shower was only about 122° and drops a good 10°-15° after only 15 gallons of use (7min shower).
I increased upper/lower thermostats to 130° and instead of increasing my temp, the temp dropped to about 118°. I found today the only solution was to turn the thermostats up to above 140° until I hear the click of the top element energizing and then back down and now I get the correct temp out of my tap/shower. I have it set to about 135° and hitting 130° on my calibrated thermometer.
I will check after family showers tonight and see if the temp reaches back to 130°. I grabbed my multimeter this morning, ensured I get full 240v, and I validated the upper/lower elements are alternating appropriately as if the thermostats are perfectly fine. I get about 12.4ohms of resistance from elements as well so those seem good. Seems parts all appear to be fine and the issue is just the thermostat not properly switching on when it should. Very aggravating for a brand new unit.
That’s working perfectly then.
I tested around again and my temp is back down at a straight 122° despite my thermostat being set to 135°. Seems only when I turn the thermostat up above 135 to force that click of the thermostat turning the element on will it heat to its proper set point, once I introduce cold water it will not heat above 122.
So far I've had it set to 125, 130, and 135. Hits that temp initially then will never go above 122. Very odd.
set the temp and leave it alone for a day then check the temp by releasing the relief pressure temp valve into a bucket. Check the temp there at the bucket.
I will try that in the morning and let you all know. Thanks.
Please remember that the numbers on a thermostat are not always accurate.
I really wish they’d stop putting numbers on them AGAIN so people won’t think they’re actually accurate because usually they’re not accurate.
Please remember that there’s a range where the thermostats are off and on.
For example if you set the temp to 130. The thermostat isn’t going to cut on at 129……
It might not come on until the temp is 124. Then it might not cut off until it hits 134……
It’s not perfect.
Also where you take the temp matters. Hot water can rapidly lose temp on the way to your fixture. Always take the tanks temp at the closest fixture or preferably through water released through the pressure and temp relief valve for accurate tank temps.
Electric water heater thermostats rely on convection of heat through the tank wall into the thermostat that’s pressed up against the tank. They’re not submerged in water. There’s a lag there…….
I really wish they’d stop putting numbers on them AGAIN so people won’t think they’re actually accurate because usually they’re not accurate.
Please remember that there’s a range where the thermostats are off and on.
For example if you set the temp to 130. The thermostat isn’t going to cut on at 129……
It might not come on until the temp is 124. Then it might not cut off until it hits 134……
It’s not perfect.
Also where you take the temp matters. Hot water can rapidly lose temp on the way to your fixture. Always take the tanks temp at the closest fixture or preferably through water released through the pressure and temp relief valve for accurate tank temps.
Electric water heater thermostats rely on convection of heat through the tank wall into the thermostat that’s pressed up against the tank. They’re not submerged in water. There’s a lag there…….
Thanks for the info.
Seems to be holding steady, I get 125° at the pressure relief. I got it set to 135°. As there are many horrible reviews on these Rheems I want to add a note for others who stumble across this forum doing a google search.
It seems some Rheems just come with bad thermostats right out of the box. As a little context, Last Friday 2/9 my local plumbers installed a brand new 40gal rheem. They were supposed to install a 50gal and I didn't catch it until Friday evening. With that said that 40gal water heater got a perfect temp reading exactly as shown on the thermostat. Fast forward to Monday 2/12 they came back out and swapped it out for the appropriate 50gal and this is the one I have had problems with. You may have to tinker with the thermostat, increasing the temp up until you hear it click and back down to a higher set point then what it reads. I get 10 to 12 degrees less than what the thermostat is set to.
Seems to be holding steady, I get 125° at the pressure relief. I got it set to 135°. As there are many horrible reviews on these Rheems I want to add a note for others who stumble across this forum doing a google search.
It seems some Rheems just come with bad thermostats right out of the box. As a little context, Last Friday 2/9 my local plumbers installed a brand new 40gal rheem. They were supposed to install a 50gal and I didn't catch it until Friday evening. With that said that 40gal water heater got a perfect temp reading exactly as shown on the thermostat. Fast forward to Monday 2/12 they came back out and swapped it out for the appropriate 50gal and this is the one I have had problems with. You may have to tinker with the thermostat, increasing the temp up until you hear it click and back down to a higher set point then what it reads. I get 10 to 12 degrees less than what the thermostat is set to.
bump the thermostat up a little until the water is the temp you want. Give it a day between adjustments and test the temp at the relief valve.
Understand that the thermostats have a on and off range, its not a digital or exact temp. The technology is 70 plus years old, it’s far from perfect. Getting water temp that matches the thermostat is luck.
ALL electric water heaters have these same characteristics, All brands unless they’re digitally controlled.
Understand that the thermostats have a on and off range, its not a digital or exact temp. The technology is 70 plus years old, it’s far from perfect. Getting water temp that matches the thermostat is luck.
ALL electric water heaters have these same characteristics, All brands unless they’re digitally controlled.
gagecalman
Well-Known Member
I was a little bored today so here you go:
I installed my Rheem 50-gallon electric last year. I looked up the replacement thermostats and here are the specs. With that much differential it seems if the temperature is within 10°, you’re doing great.
Differential or hysteresis is the temperature range between the thermostat’s switch-on and switch-off points.
Upper thermostat
High Limit Contact Configuration DPST
High Limit Control Manual Reset
High Limit Setting (F) 170
High Limit Tolerance (F) +/- 5
Manufacturer Series 59T/66T
Thermostat Adjustment Range (F) 90 to 150
Thermostat Contact Configuration SPDT
Thermostat Differential (F) 17 to 27
Thermostat Tolerance (F) +/- 5
Lower thermostat
Manufacturer Series 59T
Thermostat Adjustment Range (F) 90 to 150
Thermostat Contact Configuration SPST
Thermostat Differential (F) 5 to 15
Thermostat Tolerance (F) +/- 5
I installed my Rheem 50-gallon electric last year. I looked up the replacement thermostats and here are the specs. With that much differential it seems if the temperature is within 10°, you’re doing great.
Differential or hysteresis is the temperature range between the thermostat’s switch-on and switch-off points.
Upper thermostat
High Limit Contact Configuration DPST
High Limit Control Manual Reset
High Limit Setting (F) 170
High Limit Tolerance (F) +/- 5
Manufacturer Series 59T/66T
Thermostat Adjustment Range (F) 90 to 150
Thermostat Contact Configuration SPDT
Thermostat Differential (F) 17 to 27
Thermostat Tolerance (F) +/- 5
Lower thermostat
Manufacturer Series 59T
Thermostat Adjustment Range (F) 90 to 150
Thermostat Contact Configuration SPST
Thermostat Differential (F) 5 to 15
Thermostat Tolerance (F) +/- 5
That’s what I told him.
gagecalman
Well-Known Member
I know. I just figured with some specs on the thermostats maybe others will find this and stop trying to get the temperature within a few degrees.
