How to Find the Base Fault in a Water Furnace: A Detailed Guide

Keeping your home warm during the cold months is essential for a comfortable and happy life. Without a functioning water heater, however, that can be tricky to achieve. For you to remain comfortable throughout the winter, your home must be able to retain heat. If not, it will cool down quickly and become an icebox. This means that a faulty water heater could risk leaving you shivering in the dark come January. Unfortunately, water heaters are prone to defects and problems begin as soon as they’ve been installed. They may break down at any time of year but especially when it’s freezing outside. When this happens, you must know how to identify the culprit so that repairs can be conducted as soon as possible before things get any worse. Here’s everything you need to know about diagnosing the base fault in a water furnace.

What is a Base Fault?

A base fault is an electrical fault that occurs at the base of the water heater. It can be caused by a wide range of issues, including a faulty heating element, a blown fuse, a clogged drain, or a faulty thermostat. The most common cause of a base fault is a clogged drain. The water that flows through the heater will build up minerals over time. When this happens, the minerals will begin to clog the drain valve and reduce the flow of water out of the tank. This, in turn, causes the water to overfill the tank, overflow, and flood the floor.

Finding the Cause of a Water Heater Base Fault

To find out what’s causing your base fault, you’ll first have to locate the water heater. While they are common in homes, they can also be found in commercial locations such as hotels and restaurants. The water heater is usually found in the basement or garage. If you have a larger water heater or a tankless water heater, it will likely be located in the basement. If you have a smaller water heater, it may be in the garage. When diagnosing a base fault, you’ll need to locate the circuit breaker that controls the water heater. When you locate the circuit breaker, you’ll want to turn it off. Next, you’ll want to check the wires and fuses that are connected to the circuit breaker. When you pull the fuses out of the circuit, you should see one or more wires that have become burned or have melted.

Dirty or Stuck Drain Valve

When minerals build up in the drain valve, they can cause it to become clogged. If the valve isn’t cleaned or replaced, it can cause a buildup of water in the tank that may cause the tank to overflow, spill, or even break. If a base fault occurs and the water heater won’t turn off, the alarm will go off. When you hear the alarm, the first thing you want to do is unplug the unit and turn off the circuit breaker that controls the heater. This way, you can figure out if the problem is a clogged drain or something more serious.

Blown Thermal Fuse

A thermal fuse is designed to protect your water heater from overheating. When the pressure inside the unit gets too high, the thermal fuse will pop. This happens because the pressure inside is too high to let the water pass through the heater. The thermal fuse is designed to pop when the water is boiling. This will automatically turn off the water heater so it won’t break. When a thermal fuse pops, you’ll usually hear a clicking sound or feel a vibration. This will happen when the circuit breaker trips and turns the water heater off. When this happens, you’ll want to replace the thermal fuse as soon as possible.

Bad Thermostat or Controller

There are a few different types of thermostats. They will all tell you what temperature the water should be at. High-end water heaters will have a digital thermostat that will beep when the temperature has been reached. Thermostats that are attached to wires are a common type of water heater thermostat. When the water reaches the desired temperature, the wires will shut it off. This type of thermostat is much more common. If the water isn’t reaching the desired temperature, the thermostat may be faulty. It could also be a problem with the wiring or the controller that is attached to the thermostat. If the controller isn’t functioning properly, it can cause your water heater to malfunction.

Shorted Heating Element

The heating element is what heats the water in the tank. If the element shorts out, it could cause a base fault. This could also indicate that there is an additional issue with the water heater. To find out what’s causing the short, you’ll have to turn off the power and investigate the issue. When the power is off, you’ll want to open the water heater and inspect the element. If you see that the element has been damaged, you’ll want to replace it immediately.


The water heater is one of the most important appliances in your house. When it breaks down, life can get pretty uncomfortable. That’s why it’s so important to figure out how to fix a base fault in a water furnace as soon as possible. When you know what’s causing the base fault, you can get a repairman in to fix the problem. This way, you’ll be able to stay warm and comfortable throughout the winter months.