Why Is Your Water Not Getting Hot? 4 Common Reasons—and Our Expert Fixes

There are few feelings worse than stepping into the shower, expecting a warm cascade of water, only to be greeted by an icy blast. It's a shock to the system and a plumbing frustration. To prevent the aggravation of wondering, "Why is my water not getting hot?" we turned to a plumbing expert.

According to Dewayne Sloan, an expert plumber with over 25 years of experience, there are many reasons a water heater might not be operating at its best, but considering the following reasons should always be your first step.

1. If You Have an Electric Water Heater: Tripped Circuit Breaker or Blown Fuse

Electric water heaters rely on power from your home’s electrical system. If the circuit breaker that controls your water heater has tripped, the unit won’t receive any electricity and will stop heating water. This can happen due to a power surge, an overloaded circuit, or a short in the system.

Sloan says to pay a trip to your breaker box to see if the switch has flipped to the "off" position. If it has, simply flip the switch back. If the breaker keeps tripping, it could indicate a more serious issue. In that case, it's best to contact an electrician or plumber who can safely inspect and repair the system.

2. If You Have a Gas Water Heater: Pilot Light Is Out

If you have a gas water heater and your water isn’t getting hot, check whether the pilot light is lit. The pilot light is a small flame that ignites the burner to heat the water in the tank. If it's gone out, the burner won't function—and no hot water will be produced. This can happen due to a draft, dirty pilot opening, or issues with the thermocouple (a small device that senses the pilot flame and controls the gas valve).

Relighting the pilot light is often a straightforward task if you follow the instructions on your water heater. This can be found on a sticker near the bottom. However, if the pilot won’t stay lit after you’ve reignited it, gas valves or other components may have failed and require professional service. 

According to our expert, safety is paramount. If you smell gas or feel unsure, calling a qualified technician is safest.

3. Sediment Buildup in the Tank

If you live in an area with hard water, sediment buildup is a common cause of water heater problems. Minerals like calcium and magnesium separate from the water when heated and settle at the bottom of the tank. As time passes, this layer of sediment can get quite thick and reduce your water heater’s efficiency. 

A yearly flushing of your water heater by a professional can help prevent this issue. Sometimes, a replacement heater is the most cost-effective solution if the sediment can't be easily cleaned or removed.

4. Faulty Heating Element or Thermostat

Electric water heaters usually have two heating elements: one at the top and the other at the bottom. These elements are responsible for warming the water in the tank. Over time, they can burn out or become coated in mineral deposits, reducing their efficiency or stopping them from working altogether. A burned-out element means the tank can’t reach the desired temperature, leaving you with lukewarm or cold water.

The thermostats that regulate the temperature of your water heater can also malfunction. If a thermostat isn’t reading correctly, it may not signal the elements to turn on, or it could shut them off too soon.

Testing and replacing heating elements and thermostats is a relatively simple job for a technician. If you suspect either to be the culprit, it's the right time to hire a pro.