Water heater electric thermostat problems

3180 Views 21 Replies 9 Participants Last post by OpenSights, Mar 16, 2022

Joe P

Discussion Starter · Jan 11, 2021

Electric water heater upper thermostat never comes on because its differential temperature control is too high between 17F to 27F (it is operating at the high end of 27F). This is the temp difference range when the thermostat turns the heating element on and off. The lower thermostat differential temperature is 5F to 15F and is averaging about 10F. When testing each individual thermostat the lower thermostat comes on first at about 110F and off at 120F (10F differential). The upper thermostat comes on at 98F and off at 125F. (27F differential). This data was taken using contact thermocouples that attached to the tank next to the upper and lower thermostats. The following test was done with the lower tank temperature at 120F and the upper tank temp at 125F. A hot water sink faucet was turned on at 1.4 GPM and in 5 minutes the lower thermostat came on first at 110F. The water temperature slowly drops and over a period of 30 minutes the lower tank temp was at 88F and the upper tank temp was at 112F which still was not low enough for the upper thermostat to come on at its turn on temp of 98F. I had to run the hot water for 40 minutes before the upper thermostat turned on its heating element. It is my understanding that the benefits from having the upper heating element come on as early as possible is for faster recovery and less water temp drop.

1 - 20 of 22 Posts

OpenSights

· #2 · Jan 11, 2021

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Tango

· #3 · Jan 11, 2021

This is what I do for my customers. Gotta keep the water warm. They save a bundle this way!

See less See more

Reactions: 4

OpenSights

· #4 · Jan 11, 2021

Tango said:
This is what I do for my customers. Gotta keep the water warm. They save a bundle this way!

View attachment 127031

Are you crazy? Never store paint cans next to an electric hot water heater! A gas hot water heater is fine, never an electric!

Reactions: 5

SC Plumbing Repair

· #5 · Jan 11, 2021

OpenSights said:
Are you crazy? Never store paint cans next to an electric hot water heater! A gas hot water heater is fine, never an electric!

Too Funny......

Reactions: 2

hewhodigsholes

· #6 · Jan 11, 2021

Tango said:
This is what I do for my customers. Gotta keep the water warm. They save a bundle this way!

Is that... Qest pipe on the relief valve? My favorite! There is no better material for plumbers.

Also, this Joe P fellow seems to be an engineer. I'd recognize that brand of rhetoric anywhere!

Reactions: 3

ShtRnsdownhill

· #7 · Jan 11, 2021

Joe P said:
Electric water heater upper thermostat never comes on because its differential temperature control is too high between 17F to 27F (it is operating at the high end of 27F). This is the temp difference range when the thermostat turns the heating element on and off. The lower thermostat differential temperature is 5F to 15F and is averaging about 10F. When testing each individual thermostat the lower thermostat comes on first at about 110F and off at 120F (10F differential). The upper thermostat comes on at 98F and off at 125F. (27F differential). This data was taken using contact thermocouples that attached to the tank next to the upper and lower thermostats. The following test was done with the lower tank temperature at 120F and the upper tank temp at 125F. A hot water sink faucet was turned on at 1.4 GPM and in 5 minutes the lower thermostat came on first at 110F. The water temperature slowly drops and over a period of 30 minutes the lower tank temp was at 88F and the upper tank temp was at 112F which still was not low enough for the upper thermostat to come on at its turn on temp of 98F. I had to run the hot water for 40 minutes before the upper thermostat turned on its heating element. It is my understanding that the benefits from having the upper heating element come on as early as possible is for faster recovery and less water temp drop.

sucks for you, sounds like some azzhole engineer messed with it too much...and designed crap...

Reactions: 2

Tango

· #8 · Jan 11, 2021

hewhodigsholes said:
Is that... Qest pipe on the relief valve?

WTF is quest pipe? Are we in the legend of Zelda or something??

Reactions: 3

ShtRnsdownhill

· #9 · Jan 11, 2021

Tango said:
WTF is quest pipe? Are we in the legend of Zelda or something??

its pex, I believe...

Reactions: 3

Tango

· #10 · Jan 11, 2021

hewhodigsholes said:
Is that... Qest pipe on the relief valve? My favorite! There is no better material for plumbers.

Not pex, just a basic drop tube.

Reactions: 1

hewhodigsholes

· #11 · Jan 11, 2021

Tango said:
Not pex, just a basic drop tube.

Qest is an old gray poly-b pipe that we see in old trailers around here. It's a total nightmare to fix cause it pops pinholes everywhere and the place is usually run with 1/2" mains and 3/8" branches.

Reactions: 5

ShtRnsdownhill

· #12 · Jan 11, 2021

hewhodigsholes said:
Qest is an old gray poly-b pipe that we see in old trailers around here. It's a total nightmare to fix cause it pops pinholes everywhere and the place is usually run with 1/2" mains and 3/8" branches.

I have a mobile home I rent out upstate, its from the 80s and has that grey stuff, it crimps just like pex....so far I havent had any leak issues...

Reactions: 2

Tango

· #13 · Jan 11, 2021

hewhodigsholes said:
Qest is an old gray poly-b pipe that we see in old trailers around here. It's a total nightmare to fix cause it pops pinholes everywhere and the place is usually run with 1/2" mains and 3/8" branches.

Poly-B in my area is good stuff. Been in houses for about 30 years now, no issues.

Reactions: 1

skoronesa

· #14 · Jan 11, 2021

ShtRnsdownhill said:
I have a mobile home I rent out upstate, its from the 80s and has that grey stuff, it crimps just like pex....so far I havent had any leak issues...

It's usually only an issue when the water has chlorine or a low PH.

Reactions: 2

skoronesa

· #15 · Jan 11, 2021

Tango said:
Poly-B in my area is good stuff. Been in houses for about 30 years now, no issues.

Do they put chlorine in the water? What about flourine?

I know that in some areas the poly b is a huge fail. We had some around here and the biggest issue wasn't the poly b itself but the fittings corroding down to nothing. Some of the houses still have it after 30 ears and others it only last 5 or 15. We take some pieces out a couple times a years.

Reactions: 1

Tango

· #16 · Jan 11, 2021

skoronesa said:
Do they put chlorine in the water? What about flourine?

I know that in some areas the poly b is a huge fail. We had some around here and the biggest issue wasn't the poly b itself but the fittings corroding down to nothing. Some of the houses still have it after 30 ears and others it only last 5 or 15. We take some pieces out a couple times a years.

Yep we have chlorine. Fluoride I don't know the city wanted to put some in and there was a petition against it and I never heard of it again. I'd have to check.

Reactions: 2

ShtRnsdownhill

· #17 · Jan 11, 2021

skoronesa said:
It's usually only an issue when the water has chlorine or a low PH.

just clean well water runs through them....

Reactions: 2

RichardBull

· #18 · Jan 12, 2021

Sequence of operation is critical. 🤭 did I say too much ?

skoronesa

· #19 · Jan 12, 2021

ShtRnsdownhill said:
just clean well water runs through them....

Where I am we have lots of lime, lots of iron, or often both. And occasionally you can find both AND extremely low ph, like below 6. There is this one 4 mile stretch of road where the wells almost always have tons of sand, tons of lime, and pretty acidic water. Most get sulfur coming out of the iron too.

You'd think with all the lime it couldn't be acidic but it is.

Almost all the wells there are low output, less than 5gpm. I know this one pair of doctors(1 deceased), it's a good thing they're doctors because they had to have a new 400' well drilled, and then have that well drilled 300' deeper, twice! It's an 8" well casing over 1000' deep. AND they still only get a 1.2gpm refresh rate. They have three 300gallon storage tanks.

You'd think they could hand dig a well and indeed some have old hand dug wells, but believe you me, you don't want that nasty water. Because of all the fine sand/silt the hand dug wells get the sides clogged up quick and it ends up being surface water.

Reactions: 3

skoronesa

· #20 · Jan 12, 2021

RichardBull said:
Sequence of operation is critical. 🤭 did I say too much ?

Correct, remove pants, apply lubricant, and then insert.

Reactions: 4

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