Why Is My Water Heater Only Making Lukewarm Water?

Why Is My Water Heater Only Making Lukewarm Water

The worst time for your water heater to be on the fritz is in the winter! As explained by a Plumber near me in Bethlehem, Deluxe Plumbing and Heating, there are lots of factors causing your water heater to be producing only lukewarm water. Knowing why your appliance Is behaving this way and how to fix it can be a big help. 

In this article, we will be looking at the potential reasons that a water heater would produce only lukewarm water.

No Fuel

If you are using a gas water heater and you recently shut off the gas to your home, the pilot light in your gas water heater will have gone out, therefore allowing the temperature of the water inside the heater to slowly go down. To fix this problem, you will need to ensure that the gas supply to the water heater is turned back on and the pilot light is re-ignited. To re-ignite, many gas water heaters require you to set the gas valve to “pilot,” then push the ignition button. For step-by-step instructions for your water heater, consult with your water heater’s owner’s manual.

Broken Dip Tube

The dip tube of your water heater could be broken. The dip tube is the piece inside the water heater that directs cold water from the top of the tank down to the heating elements at the bottom of the tank. If this dip tube is broken, it could fail to redirect water to the heating elements, which leads to disappointing lukewarm water. Most of the time, a broken dip tube usually warrants a replacement of the entire water heater.

Faulty thermostat

If you are using a water-based heater, the problem might be caused by faulty thermostats. Every water-based heater has a two-cylinder thermostat.

Be sure to check both thermostats, since malfunction of even one could make an issue such as lukewarm water flowing from the hot water tap.

A thermostat malfunction could occur, therefore leading to a fault in the measurement system. If your thermostat shows the wrong temperature, it will make the cylinder to stop warming the water before it is warm enough. This may cause the water heater to produce only lukewarm water.

A tripped breaker

There is a possibility that you had not spotted that the breaker responsible for your heater was tripped.

This may cause water warming in the cylinder to be stopped. In some cases, the water warmed inside the heater may remain lukewarm for days before it becomes cold.

If the heater’s breaker was tripped, it could cause the heater to stop working. This might be the reason for making only lukewarm water. To check if this was the cause, return the breaker to its position and check to see if the heater has started warming up the water again.

Sediment buildup in the tank

Another cause of hot water not being warm enough is sediment buildup in the water heater tank.

Water that goes into your heater tank often carries dissolved debris, minerals, and small amounts of sand. When the water settles in and is heated by your water heater, this debris mostly settles to the bottom of the tank.

Most of the water heater burners are located at the bottom of the tank. So, this buildup of dirt can make your heater’s burners less effective at heating water, leading to lukewarm water.

Clogged Pipe

Sometimes, your water heater could be making lukewarm water because of clogged pipes that are stopping much of the hot water from getting to where it is supposed to go. You can be able to tell if this is the problem you are experiencing by the way that the hot water is available in all facets of the home except for those that their pipes are clogged.

To fix this problem, you will need to have a plumber locate the clog in the pipe and replace that section of pipe or snake the pipe to remove the clog. If this is done properly, the hot water in the heater will be able to come on full-blast, and after that, you should have all the hot water you ever need.

Broken Thermostat

If the thermostat of your gas water heater is broken, your water heater’s burner may not be able to work properly or work at all. To test if your heater’s thermostat is broken or not, set the water heater temperature to the highest. Next, wait for a while to allow the gas burner to kick on. If the burner does not’ kick on, this is a sign that the thermostat is broken.


If your gas water heater is only producing lukewarm water and you cannot determine why now is the time to address the problem. Most of the issues that your water heater is experiencing should be fixed by a qualified and licensed plumber. They will be happy to come to your home, diagnose the issue, and get it fixed.