Water Heater Keeps Blowing Fuses – Causes + Fixes

Not again! It’s so annoying when your water heater blows a fuse for the umpteenth time. Do you want to know why you keep getting this problem? Here are a few suggestions from professional plumbers:

If your water heater keeps blowing fuses, it may have a faulty thermostat, bad connections or wiring, or a defective heating element. The water heater itself may also just be too old and due for a replacement. 

Before you buy another set of fuses, follow the instructions below on how to detect and resolve these issues yourself—all without forking over dollars for expensive labor and repairs.

Reasons Why Water Heaters Keep Blowing Fuses 

Let’s talk about those unbearable ice-cold baths when the fuse blows up. It’s not a pretty experience. So let’s get to the root causes of this issue. 

Bad Connections 

Here’s a common reason for blown fuses. A bad connection can overload the hot water heater circuit and blow up the fuse. Furthermore, it causes arcing and overloads the system. 

What’s more? It’s often the fault of the repairer contracted to install the hot water heater. The repairer may have added too many junction boxes and breaker connections than necessary. 

electrical wiring

Faulty Wiring

A water heater fuse will continually trip if the wiring is too small to handle the voltage requirement. Loose wires can also cause the system to trip. Thus, it is vital to use the correct wire size when installing a hot water heater. 

This once again boils down to a shoddy installation. It’s why professional and licensed electricians recommend using a wire larger than the required size for water heaters. 

For example, you must use an 8-gauge wire for a 30 to 40 amp water heater. On the other hand, use a 10-gauge wire for a 25-amp water heater. 

Bad Fuse Holders or Loose Connections

Sometimes, a worn-out fuse holder is a reason for a bad fuse. Metal contacts in fuse holders wear out and do not make contact anymore, causing the fuse to heat up. In addition, a loose connection in the fuse holder can also result in blown fuses. 

Defective Heating Element 

A bad element is more common than you think. Heating elements not fully submerged in water may heat up and burn out. Further, the internal part of the element becomes exposed to water and overloads the current entering the unit. 

In the case of a bad element, it’s better not to reset it since it may compound the damage. Call an electrician to repair or replace the defective part. 

water heater heating element

How Can I Detect a Faulty Heating Element 

The heating element may be the culprit if the remaining hot water is enough for a shower. However, this method is not foolproof. 

You can test the resistance level of the water heater to determine if the heating element is responsible for your blown fuses. For this method, use the following steps:

  1. Unplug the water heater from the main power outlet. 
  2. Open the access panel and move the insulation out of the way. 
  3. Remove the insulation cover on the element. 
  4. Remove the power wires to isolate the heating element from the circuit.
  5. Use a multimeter to test the resistivity of the element. Be sure to set the meter to continuity.
  6. Place a lead on each of the element’s terminals. The meter should read 10 to 30 ohms if it’s still functioning. In contrast, a faulty heating element will not show a reading at all. 

Tank Is Too Old

The average lifespan of a water tank depends on the region. Water heaters may last anywhere from 8 to 30 years in most cases. Older water tanks are less efficient and often develop multiple faults besides blowing up fuses. 

Defective Thermostats

Thermostats regulate the internal temperature in water tanks. They shut off the power supply to the unit if the elements become too hot. 

However, a defective thermostat can cause chattering, a situation where the element comes off. Chattering overloads the internal part of the circuit and causes the fuse to blow. 

How to Keep Water Heater from Blowing Fuses 

As a general rule of thumb in repair, identify the root of the problem before digging around. Don’t guess the cause since you may end up hurting the appliance or aggravating the situation.

If a bad fuse holder is the problem, clean it with sandpaper and get a delay fuse to detect short circuits. Contact an electrician if you think the connection or wiring is responsible for the issue. It is dangerous for unlicensed repairers to check or try to tamper with wiring.

You also need a licensed electrician in order to structure the connection in line with your region’s building codes.

How to Replace Heating Elements in Water Heaters 

When you have the right tools, replacing a faulty heating element is pretty straightforward. 

  1. Start by purchasing a new heating element at your local hardware store. In addition, get a 1½-inch socket to remove the defective part. 
  2. Unplug the water heater from the main switch.
  3. Close the cold water inlet valve and drain the water heater. 
  4. Open the control panel and remove the insulation to access the elements. Remove the wires connected to it. 
  5. Firmly place the socket on the element and turn it clockwise. You should be able to loosen the part and remove it with a few turns. 
  6. Replace with a new element, and use the socket to screw it tightly into position. 
  7. Reattach the wires, close the access panel, and plug the unit into the main power supply. 


Now you have a complete list of the possible reasons why your hot water heater keeps blowing the circuit breaker. Some of the reasons are not easy to fix, so get a professional plumber or licensed electrician to help with more risky tasks.