Test
circuit breaker and electricity
to water heater
 Push in ECO reset |
 2-element tank is 240Volts Top screws test 240Volts |
 Test Black to ground Test White to ground Test Black to White |
 240 Volt breaker |
A) This information is for ordinary tank-type electric water heater.
Troubleshoot gas water heater
B) SAFETY FIRST INSTEAD OF LAST Steps assume you have electric wiring knowledge and can safeguard from electric shock.
Do not stand on bare ground, put down dry boards, do not lean into metal or touch metal, do not touch water heater that is wet or was wet unless power is confimed OFF. Flooded water heater
Tape tester leads to wood sticks to keep hands away from power, wear dry clothes, do not sweat.
C) Check that water heater is completely full of water, and tub faucet runs full stream with no air gaps.
Note: If elements are not fully immersed in water, they will instantly burn out.
If upper element is burned out, then tank will have NO hot water.
If lower element is burned out, but upper element is good, then tank will have some hot water.
How-to-test-water-heater-elements
How-electric-water-heater-works
How-to-troubleshoot-electric-water-heater
How to wire thermostats
D) If tank is in working order, that leaves ELECTRICITY as main suspect.
How to test circuit breaker and electricity to water heater:
1) Open cover(s) located on side of tank: Remove insulation and plastic insulators. Look for loose and burned wires that indicate location of problem. What to do if wires are burned/ melted
Push in ECO red reset button on upper thermostat. Push very firmly.
If ECO is tripped out, then that cuts power to water heater and heater will not work.
If ECO will not reset and stay pushed-in, then replace upper thermostat.
After pushing in reset, put ear against tank to hear if tank is heating. If no sound, move to next step.
If ECO is not tripped, move to next step.
How water heater thermostats work
How-to-replace-thermostats
2) -Buy cheap multimeter from Home Center and set dial to 240-250 VAC
-Tape tester leads to woods sticks to keep hands away from power.
-Stand on dry boards, touch no metal, wear dry clothes.
-Power is ON
Test across top two screws on upper thermostat: Should read 240Volts.
If test does not show 240Volt, then check connections at top of tank.
Test each screw to bare metal part of tank. Test should show 0 volts.
If this test shows 240Volts, then circuit to water heater is good: Troubleshoot tank electricity
If test does not show 240Volts, then move to next step
3) Test connections at top of tank: Test across both insulated wires: should read 240Volts.
Test Black to bare ground: should read 120Volts
Test Red to bare ground: should read 120Volts See basic water heater circuit
Re-install wire nuts very tight, and close cover. Make sure bare ground wire is connected to green screw. Wire nut basics
If test does not show power, then circuit breaker is bad or wire between water heater and circuit breaker are bad.
4) Test circuit breaker
If breaker is tripped off on one leg, then water heater can receive 120Volts and appear to have electricity, but water heater will not work. Ground wire is not needed for 240Volt circuit to work. How 120 Volt and 240 Volt circuits work
To test circuit breaker, push circuit breaker lever all the way one direction and then back other direction to make sure breaker is latched. Listen for craclking sounds and smell of burning that indicate location of problem.
Jiggle breaker around and listen for crackling or fizzing sound that indicates breaker is shorting.
Check if breaker feels warm.
Check for smell of burning that indicates breaker has overheated or shorted.
If breaker next to water heater breaker has overheated, that can cause water heater breaker to fail. Touch other breakers and check for hot or warm breaker.
Hot breakers indicate that circuit is overdrawn or that breaker is failing, or both.
5) Mark breaker for identification, and remove panel cover.
Stand on dry boards. Never stand on bare soil. Do not lean into or touch metal. Do not hold metal object in mouth. Wear dry clothes and dry shoes. Never touch wires that enter main breaker.
Stay away from main breaker no matter if main is ON or OFF <> live power at main breaker
Turn off breakers on both sides on water heater breaker for safety.
Turn Off water heater breaker and thighten each wire on water heater breaker.
Turn breaker ON and test across both wires on breaker for 240Volts.
If breaker tests for 240Volts, but top of tank is still not receiving 240Volts, then inspect wire between breaker and water heater for damage. This can indicate fire hazard caused by rat gnaws on wire, or nail that was accidently put into wire during construction, or junction box between breaker box and water heater that has loose wire.
If breaker does not test for 240Volts across both wires, then replace breaker. How to replace circuit breaker
For temporary fix, move wires to another same-size breaker until water heater breaker can be replaced.
If breaker checks out, and suddenly water heater heater has 240Volts and is working, then breaker is still suspect. Move wires to another same-size 240Volt breaker and see if problems continue.
If breaker will not reset: disconnect wires from top of tank and see if see if breaker resets. Disconnect wires from breaker and see if breaker resets. If breaker does not reset, then replace breaker. If breaker resets after disconnecting water heater, then tank has a short: Remove all wires from thermostats and elements. 1) Test elements 2) Test wires 3) Re-inspect for burned parts and wet tank. 4) Replace thermostats, replace any burned part
6) If you are getting 240 to water heater, but heater is not working, then wire inside tank could be loose.
-Do 30 minute troubleshoot:
How-to-troubleshoot-electric-water-heater
Use 30 amp breaker and 10 gauge wire on 240Volt water heaters
Overheating can damage main panel busbar, requiring new subpanel or replacement of main panel. See breaker/ wire size chart How to install subpanel
Over-amped main panel can also cause water heater failure. Add up total amp usage of everything in house. Volts x amps = watts. or Watts divided by volts = amps. If you are overamping, then turn off swimming pool pump and other main consumers to draw back until main panel can be upgraded.
Failing main breaker can also cause water heater failure. Put hand on main breaker and see if it feels warm or hot.
 Larger image | Check label on side of tank for volts and watts Every appliance, switch, outlet and bulb has a label Residential water heaters with 2 elements are 240Volts Residential water heaters are non-simultaneous This means both elements are never ON at same time. Element wattage is tank wattage If tank has 4500 watt elements, then tank wattage is 4500W Recommend 30 amp breaker and 10 gauge wire for all 240Volt water heaters Figure volts amps watts for water heater How to wire thermostats and elements How to wire off-peak water heater |
 | Basic 240Volt water heater |
 | How to replace circuit breaker |
