No hot water during a freeze

CA Traveler wrote:

Dusty R wrote:

S Davis wrote:
Water that has been heated will freeze faster than cold water, it has less air entrained in the water than the cold.

What if you have 2 pans of water, one has been heated, but both are now the same temperature. Will they now both take the same amount of time to turn to ice?

No and it has nothing to do with air in the water. See my 10:12am post today.

What do you mean No, even the article you referenced says they don’t understand why, do you have some credentials or experience you want to share? I am not saying hot water freezes faster but water that has been heated and has cooled off afterwards in the piping.

Mpemba-two-water-probes.svg
The Mpemba effect is a phenomenon in which hot water appears to freeze faster than cold water. The phenomenon is temperature-dependent. There is disagreement about the parameters required to produce the effect and about its theoretical basis.

Dusty R wrote:

S Davis wrote:
Water that has been heated will freeze faster than cold water, it has less air entrained in the water than the cold.

What if you have 2 pans of water, one has been heated, but both are now the same temperature. Will they now both take the same amount of time to turn to ice?

Have never tried two pans, the difference would obviously be a pressurized versus non pressurized test which could have two entirely different outcomes. I do know in my 32 years in plumbing and hydronic heating that hot water lines can freeze before the cold. I worked in plumbing and heating in South Lake Tahoe and have probably over 1000 hours running a pipe thawing machine and in my experience 90% of the time it was the hot water side that had the most freezing and pipe damage. You guy’s can argue all you want about why but I am giving you real world experience.

My low point drain valves are inside so no water transfer of cold from drain line water. I'm thinking that any cold transfer from the empty drain line is very minimual and perhaps the inside hot water line causes a small amount of heat tranfer to the outside.

Old-Biscuit wrote:

rhagfo wrote:

noteven wrote:
What is not a myth is if the supply line to or from your hot water heater freezes hot water will not appear at the taps.

Scout around for where lines are run are they inside the heated space under a cubbard up against a cold wall? If yes open the doors to the space and turn the heat up to about 90. Crack a hot water tap on. When it starts to spit and flow the line is thawed. If you have a small fan to move some air through the space with the doors open that's better yet.

If your lines are outside in the cold oops

Well seeing how the water connections to the WH are in an interior space I think the supply line is less likely than the hot water line after the the WH freezing. This would only be likely if the WH was remote from all other water using devices, which is not likely.
More likely is the hot water line, after the heater run in a somewhat cold space. In our 5er we have a run of about 15’ where the lines (cold and hot) run in the floor space (2”) on the outside edge of the floor. If we will see extremely cold temps, I will likely put some put some of the foil bubble wrap under that area.
My bet is still on the exposed hot water low point drain.

Why would a hot water low point drain affect hot water flow at a faucet......LOW point drain

My bet issue is AT the WH Tank...cold in or hot out
Cold in could be frozen
Hot out...check valve jammed/clogged

Old Biscuit, did you think about the fact that the connection end of the WH is typically in a heated or somewhat heated space.
Our low point drains are located under our kitchen near the back of our 5er as is our WH, the hot water line passes through the T to the low point drain before going anywhere else.

Dusty R wrote:

S Davis wrote:
Water that has been heated will freeze faster than cold water, it has less air entrained in the water than the cold.

What if you have 2 pans of water, one has been heated, but both are now the same temperature. Will they now both take the same amount of time to turn to ice?

No and it has nothing to do with air in the water. See my 10:12am post today.

S Davis wrote:
Water that has been heated will freeze faster than cold water, it has less air entrained in the water than the cold.

What if you have 2 pans of water, one has been heated, but both are now the same temperature. Will they now both take the same amount of time to turn to ice?

Water that has been heated will freeze faster than cold water, it has less air entrained in the water than the cold.

I have not read every entry, but I would bet you have a water line frozen somewhere. Take a hair dryer and plug it in turning it on fo about 1/2 hour starting from the access to the pipes in the rear of your water tank and proceed to other area where the water line runs. Try after each process. Cold water enters the heater, is heated, then leaves to travel to your various faucets. Good Luck! Hope your pipe did not burst when frozen. Watch for leaks when you thaw also.

time2roll wrote:
Heated water does not freeze.

Hard to disagree with that! We occasionally hear someone thinking you shouldn't put a battery on a concrete floor.

Heated water does not freeze. You need to add heat to the pipes to get them to flow again.