Inconsistent Water Temperature

inconsistent water temperature

Call us at (559) 940-0890

It can be dangerous, and sometimes even annoying, when your home water temperature is inconsistent. Taking a comfortably warm shower that suddenly turns cold can be very unpleasant. There may be a number of different reasons for your inconsistent water temperature, but the following can help to mitigate this issue.

Inconsistent Water Temperature in Your Bathtub or Shower

The water temperature from your tap may be affected by a demand for water somewhere else in your home. This may very well be the most common cause of inconsistent water temperature. A new water demand can come from the flushing of a toilet or use of a dishwasher. Since your home’s water demand is connected to a central service, both hot and cold water are shared throughout your home.

This problem can be counteracted by using thermostatic and pressure-balanced tub/shower. Inconsistent water temperatures can often be fixed by shower cartridge replacement.

Shutoff the Water

Shut the water supply and cover the drain stopper.

Remove the Handle

Use the appropriate Allen wrench to take off the handle. Use a Phillips head screwdriver to disconnect the handle adapter.

Replace the Cartridge

Carefully take out the metal clip that holds the cartridge steady. Position the new cartridge with the hot side leftward. Replace the retainer clip of the cartridge.

Fix the Handle and Guard

Fix the scald guard. Adjust it while the water is turned back on and running. Then replace the handle.

Inconsistent Water Temperature from Faulty Dip Tube in Your Water Heater

Your home water temperatures may also be inconsistent due to a faulty dip tube on the cold water side of your conventional tank-based water heater. Your water heater has two pipes at its top extending into it. One of the dip tubes goes nearly all the way to the tank’s bottom, forcing cold water there. The other is quite shorter and collects hot water from the top of the tank.

There are several ways the cold water tube can develop a fault. It can get completely snapped off at any point. It may also crack, corrode, or leak anywhere along its length. When this happens, hot water mixes with the incoming cold water, resulting in unsteady water temperatures or even lukewarm water again and again. Rather than replace the heater, you can easily replace only the dip tube.

Prep the Water Heater

Turn off the water heater’s electric or gas supply and drain the unit.

Take Out the Vent Stack

Use Phillips head screwdriver to remove the vent slack located at the water heater top as well as the metal shield attached to it.

Detach the Copper Pipe

Cut the copper pipe above the heater about 8 inches using a hacksaw or copper pipe cutter.

Take Out the Copper Fitting

Use the pipe wrench to keep the dip tube fitting steady while using the crescent wrench to disconnect the copper line fitting. Take out the copper fitting and place it aside.

Take Out the Dip Tube

Turn off the dip tube fitting using a pipe wrench. Once it gets free, pull the dip tube straight out of the heater using your hands.


If the dip tube hits the ceiling and is stuck when pulling it out (especially for low ceilings), you will have to lay down the tank to completely remove the tube.

Ready the New Dip Tube

Use the hacksaw or PEX cutter to cut the new dip tube about 3 inches short from the water heater bottom.

Fix the New Dip Tube

Slip the replacement dip tube right down into the heater. Use Teflon tape to wrap the threads, and then screw it in position using a wrench.

Complete Installation

Use 1/2-inch pushfit connectors to reconnect the two copper pipes to the 1/2-inch flexible braided line.

Inconsistent Water Temperature with Tankless Water Heaters

Tankless or on-demand water heaters save energy by not heating and storing a large volume of water for when needed.

A typical shower consumes water around 2 gallons per minute, and a tankless water heater is able to supply 4 to over 10 gallons of hot water in a minute, subject to the model. In any case, higher hot water demand can outdo a tankless water heater capacity, but new tankless models can be fixed in parallel to address this.

Descale the Water Heater

The ability of your water heater to heat water effectively can be hindered by rust, oxides, carbonates, and other mineral deposits. Using a descaler cleaning kit every year or 18 months can help free your unit from these deposits.

Descaling kits cost between $140 and $200 but are essential for maintaining your tankless water heater.

Check for Obstructions

Vermin, nests, or some other debris may block vent pipes and affect the operation of your water heater. Inspect and clean all exterior vents.

Assess Your Water Needs

Cold water sandwich occurs when your heater toggles between hot and cold water. At this point, the system is servicing two water needs. You can either space out your water needs or replace the water heater with a tankless system with higher output.


If you are experiencing a cold water sandwich, first of all check the connection to ensure there is no crossing between cold and hot water lines. This normally happens after installing a new fixture or appliance. (Even a faulty solenoid valve of a washing machine can cause this problem.)

Call us at (559) 940-0890
Clovis Plumbing Services