Thread: Highest water temp measured so far

Yesterday I measured a temp of 176 degrees at a bathroom faucet. The control on the gas water heater was set just below the medium setting.
I've never seen temps that high before.

Originally Posted by Jack Feldmann

Yesterday I measured a temp of 176 degrees at a bathroom faucet. The control on the gas water heater was set just below the medium setting.
I've never seen temps that high before.

That is high....
I have never seen one that high either. Sounds like a bad thermostat on the tank...

I hope they had a working TPR valve!

The TPR was holding strong!!!! Not a drip of water was leaking out! :-(
I'm going back today to pick up the radon monitor, so I will ask the home owner what repairs were done.

Originally Posted by Jack Feldmann

The TPR was holding strong!!!! Not a drip of water was leaking out! :-(

The T&P relief valve should be holding strong without any drips - it should not open until 210 degrees, that water heater still has 30 degrees to go before the T&P opens, and the T&P should not open until 150 psi (while you did not take the pressure, I doubt it was 150 psi).

Anything less and the T&P could be deemed as being defective and needing to be replaced. Of course, if the T&P relief valve is stuck closed ... no one would know that until the water reached 210 degrees or the pressure reached 150 psi ... and then I would not want to be standing there monitoring it.

HEAD SLAP MOMENT!!!!! You are right Jerry, I had pressure in mind instead of temp. I knew the 150!
I still have a burn on the back of my hand where it touched the pipe coming out of the top of the water heater.
By the way, I did measure the pressure in the house, and it was below 80 psi.

However, the listing agent did not notify the home owners even after an email and phone message. They are going to have a plumber look at it today.

Pfft!!! That's nothing! Don't know the temp, but I bet higher than 212° would be a safe bet. Electric water heater, no T/P valve, vacant house. This was a couple of years ago.
Hot Water 2.JPGHot Water 3.JPGHot Water 6.JPG

Originally Posted by Gunnar Alquist

Pfft!!! That's nothing! Don't know the temp, but I bet higher than 212° would be a safe bet. Electric water heater, no T/P valve, vacant house. This was a couple of years ago.
Hot Water 2.JPGHot Water 3.JPGHot Water 6.JPG

Gunnar,

I wonder how much longer that water heater had before the neighbors a couple of blocks away would be collecting it from their yard or roof?

Those photos are . I've had steamy water before which I always referred to as 'steam' because of the steam with the water, but I suspect you have true 'steam' and no water.

Let's see, water at atmospheric pressure at sea level turns to steam at 212 degrees and thus gets no hotter than 212 degrees.

If we presume that water heater was still less than 150 psi (the T&P is *supposed to* open at 150 psi, and if we presume the T&P was still operative then the pressure would be less than 150 psi), so, let's presume the pressure was only 130 psi ... at 130 psi the boiling point of water is approximately 350 degree (give or take a few degrees). I doubt the water in the tank was boiling, which means the temperature and pressure in the tank were less than those numbers.

If we revise the pressure down to 50 psi of a well system, the boiling point would be 281 degrees - which should still have opened the T&P relief valve at 210 degrees.

Hmmm, if we presume the T&P relief valve was functional and would have opened at 210 degrees but was not open, then the temperature of the water would have been less that 210 degrees. Let's go with 210 degrees.

As soon as you open the faucet and let the water out at atmospheric pressure, the water boils to steam at less than 80 degrees (79.6 degrees at 0.5 psi), so the water temperature was somewhere over 80 degrees but less than 210 degrees.

This is fun ... sort of.

ADDED WITH EDIT: OOPS! I made a major math error as I was thinking psi as in psig (psi gauge), however, the chart I was looking at was psia (psi absolute). That means that psig would have been at the psia level of 14.6, and the 0.5 psia pressure is WAY TO HECK DOWN THERE near a total vacuum.

BIG math error there.

So, it was fun, but totally meaningless. Oh well.

Jerry, you missed where he said No TPR

Rick is correct. No T/P valve. Jerry, you are correct. No water (at least for a while); steam hissed out of the faucet! The electric water heater was VERY old. Country property, but I think it was on a mutual water system, not a well. With the mutual supply, at least the hot water could expand back into the supply instead of exploding. I don't know the supply water pressure and my IR thermometer was not working at the time. I kept thinking of the Mythbusters water heater launch.

When I turned on the cold water valve at the kitchen sink, I got really hot water and immediately thought that the hot/cold was switched. So, I turned on the hot valve and got steam! Blew my mind. I had never seen that before. I evacuated the buyer and agent, let it run for a while to introduce cold water into the tank and turned-off the 30 amp water heater breaker. When the water in the tank had cooled a bit, I checked the water heater to find the power was still on! Not only was there a problem with the water heater, but the circuit breakers were screwed-up as well. I had to turn off two separate single-pole breakers to interrupt power to the water heater.

Very cool Gunnar!!!!! Not cool as in temperature, but VERY COOL!

Super heated water. When water is under pressure, its boiling point is raised. When you open a tap the super heated water flashes to steam. This is what causes a water heater tank rupture be so violent. All that super heated water flashing to steam taking up 10 times the space a gallon of water uses.

Reminds me of one of my favorite watering holes in Durango, CO--Steamworks Brewery. Great burgers, too, although not quite as good as Gazpacho or Farquardt's.