Water may stay hot for 5 minutes then gets cold. water heater often blows breaker or pop out switch.

You have an issue. The water heater is Kaput! Bad! No more! You need a new one!

You could start by seeing if the thermostat is wide open. Sounds like it is on low or vacay mode. How far is the run between your heater and the bathing area. Might need to insualet some piping.

1) Test elements, and if elements are good, then replace both thermostats.
Takes about 20 minutes. Power is off.
http://waterheatertimer.org/How-to-test-water-heater-element.html
http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html

2) Label on side of water heater shows volts and watts.
For 4500 watt elements, you need 30 amp breaker and 10 gauge wire.
Move water heater wires to different same-size breaker.
http://waterheatertimer.org/Color-codewire.html

3) Open the links and do the work, or call plumber to do work, or call manufacturer for warranty coverage.
If your wire and breaker are problematic, then service is not free.

I don't have specific suggestion for tankless tripping breaker or if that is a circuit breaker problem or a tankless problem.

1) Move wires to another same-size breaker and see if problem persists.

2) Compare amp draw on tankless label with wire size and breaker size amp rating.
For example 30 amp breaker using 10ga wire is rated for 80% of listed amps or 24 amps.

3) If you are drawing full 30 amps, then 30 amp breaker is getting hot. Breaker trips with heat. Older breakers can trip more easily.
http://waterheatertimer.org/How-to-replace-circuit-breaker.html

4) Before calling service technician, open following link for Bosch troubleshooting steps.
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

5) Be sure to read manual for yearly maintenance requirements.

6) Add a tempering tank for incoming cold water problem.
http://waterheatertimer.org/Tempering-tank.html

7) All gas tankless brands can be repaired by homeowner for $330.
http://waterheatertimer.org/How-to-install-gas-water-heater.html

Hi,
The dip tube on the cold water side either is not there or it is broken off then the cold water stays on the top and gives cold water quickly...

If this is a new installation then check that the piping is correct and that the cold and hot pipes are not switched...

heatman101

Question: Do Low boy heaters, have a heater at the bottom, AND at the top?--- and are BOTH of the heaters working, on the 'either/or thermostat?
(By 'either/or'-- I mean, that it first turns the top element on, and when it is satisfied, THEN it turns the bottom on, until the whole tank is heated..) -- I would say this is an advantage of the taller tanks...

The taller tanks stratify VERY WELL--- (And the incoming cold water stays right at the bottom, and you take the HOT water off the top-- until suddnely it all goes to COLD.

I am wondering if the Low boy heaters might MIX more thatn the tall ones,-- thus going to WARM water sooner--- due to poor stratification.
Could you test that out, and try to folow the cold water line up the tank, as the Hot water is drawn off?

Another thought:
The Cold Fill tube, does go all the way DOWN to the bottom of the tank, right?--
And does it gently let the cold water flow across the bottom, and not 'rotatee the waer in the tank, as it replaces the hot water being used?
Otherwise the cold water will mix very early-- and give this same problem...
(I have heard of those center tubes falling off in shipment...
Did you by any chance check that, when you installed it?)

A final thought: What if the water draw was extremely fast?-- (Like if the water pressure is exceptionally HIGH--) might that upset the stratification, and cause the same problem, too?

If the hot water is drawn more slowly, can the customer get 30 or 4 gallons of HOT water, before it all goes cold?

Mack B

Replace the melted part.

If tank is popping breaker, then the melted part has a short circuit.
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html
When replacing thermostats, I usually replace both of them
http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html

There are 5 basic parts to electric water heater.
Electricity to water heater.
Upper thermostat
Upper element
Lower thermostat
Lower element
It sounds like electricity is good.
Elements are probably good if just replaced, but one of them could have a short.
Thermostat is melted, so replace it and see if it restores hot water.
If not, then take 40 minutes and do complete troubleshoot as shown in link above.

Add a comment for more free help.
Also take advantage of fixya phone service.
For a price, expert speaks with you over phone while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.

1) Shut the breaker off to it at the panel. 2) Hook a hose up to it (the bottom has a drain). 3) Close the valve to the water heater (on the cold water supply). 4) Open drain on the bottom of water heater. 5) Open the relief valve to allow air into the tank (it won't drain otherwise - think if you put your finger on one end of a straw - the liquid stays in until you let go). Why are you draining it by the way?

check diaphrapm valve or micro/switch best of luck

Unit needs a new "dip tube" It is cracked and allowing cold in water to mix with all hot water resulting in "lukewarm water". Need plumbing skills to change out at cold inlet top of heater,pull out old,buy new at hdepot 5.99 reinstall.

Please rate Thanks

jj505