Residential Electric Troubleshooting Table

Nature of Problem

Possible Cause

Service

No Hot Water

Manual Switch Turned Off

Blown Fuse Breaker

High Limit Switch Tripped

Upper Thermostat Defective

Upper Element Defective

Grounded Thermostat

Thermostat Out Of Calibration

Improper Wiring

A) Shorted or Loose Wiring

B) Undersized Service Wire

Turn to ON

Replace or reset

Manually reset ECO button

Check and replace

Check and replace

Check and replace

Check, tighten and replace

Check and replace

Not Enough Hot Water

Thermostat set too low

Defective lower element

Defective lower thermostat or miswired thermostat

Improper wiring

Loose wiring

Improper heating elements

Scale formation on heating element

Thermostat not flush with tank

Poor grounding of tank

Heater is undersized

Damaged dip tube

Increase thermostat setting not to exceed 120 degrees

Check and replace

Check and replace

Rewire per wiring diagram

Check and tighten

Check wattage and replace

Check elements; clean or replace

Position thermostat so back touches the tank

Check grounding and tighten

Resize residence and compare

Check and replace

Water Too Hot

Thermostat setting too high

Thermostat out of calibration

Thermostat not flush with tank

Grounded element

Lower thermostat setting

Check and replace

Position thermostat so back touches the tank

Check and replace

Slow Hot Water

Heating elements too small

Lower thermostat is defective

Check wattage and replace

Check lower thermostat and replace

Noisy Heating Element

Scale build-up on elements

High watt density elements in the heater

Remove, clean or replace

Install low watt density elements

Excessive Relief Valve Operation

Excessive water pressure

Excessive temperature

Install proper pressure reducing valve on cold side

Check for open or closed system. Replace T&P valve and install thermal expansion tank

Check thermostat; lower setting or replace; check for grounded element.

Rusty Or Black Water

Scale formation on elements

Anode rod dissolved

Excessive sediment build-up

Clean or replace elements

Check anode rod and replace

Try to drain tank; replace tank if sediment build up is excessive

Water Heater Is Leaking

Cold in or hot out joints

T&P valve

Heating elements, anode rod and gaskets

Inner tank has a pin hole

Check joint and repair

Check valve and replace

(Caution: Do not confuse normal T&P operation as a leaking tank. If the puddle dries up, then look for a T&P problem.)

Check, tighten and replace

Replace water heater (When diagnosing a leaker – you will notice a puddle of water on the floor, next to the heater, that will not go away.)

Smelly Water (rotten egg odor)

Bacteria Formation inside  Water Tank

Clean tank using chlorine bleach

Replace anode rod if deteriorated

Add automatic chlorine feeder to cold water inlet side of tank

Milky Water

Aerated Water

Allow a glass of hot water to set for a few minutes. If the water turns clear, the condition is a natural occurrence. See water chemistry section