Hot water heater flow problems.

Some of the old gas water heaters used electric water heater thermostat.
Just use a standard thermostat.
http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html

http://waterheatertimer.org/http://waterheatertimer.org/Add-another-thermostat-to-gas-or-electric-water-heater.html

http://waterheatertimer.org/How-to-replace-thermostat-on-gas-water-heater.html

Gene


Water Heater Timers Save Money

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

The real question is 'How old is the water heater?'... over time, particularly in areas with hard water, sediment builds up in the water heater. Particularly electric models. typically a TPV (temperature/pressure relief valve) won't cause the symptoms you describe, but mineral deposits around the inlet tube (internal) could, by restricting the flow of water into the water heater.

A TPV is designed to prevent over pressurization which could cause the tank to rupture. I have priced new water heaters as low as $308.00 for a gas powered 40 gallon unit with a 3yr warranty. If you have good soldering (sweat fitting) skills, these are relatively easy to replace yourself. Whether electric or gas, make CERTAIN you shut off the heat source before attempting a replacement.

http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html#reset

http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html#new

Gene
Water Heater Timers Save Money

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Is this gas or electric:
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html#new
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html
http://waterheatertimer.org/How-to-install-gas-water-heater.html

Add a comment with more information.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

turn the power off and flush it out by letting the tap run for an hour or so
i think it could have lime scale in it or the element is about to blow if its the type that you can get the top off look inside it you may see the fult even kettle cleaner may be needed to clean it out, but dont go drinking that water???

There could be blockage in your water heaters venting on the outside of the home. It sound like the high limit switch has been tripped. Try unplugging the tank and plugging it back in. this will reset the tank. if the problem persists you will want to call your provider for service.

you have a couple things that may cause this. you may have a bad element a bad thermastat a tripped eco (emergency cut off ) or problem with electric suppling heater.if you have no electric backround or training you should call a pro

You say a very new water heater. You won't get 40 gallons of hot water from a 40 gallon water heater because the continuing influx of cold water will cool your hot water down. However, it appears that your bottom water heater element needs replacing. If the top element is bad, you'll get no hot water. If your bottom element is bad, you'll get "some" hot water. Try replacing the bottom element. DON'T FORGET to turn off the electricity AND water first (closeby towels are also handy)!