Why am I getting hot water when I turn cold water tap on? (2023 Update)

There could be several reasons why you are getting hot water when you turn on the cold water tap. Some common causes include:

Cross connection: A cross connection occurs when the hot and cold water lines get mixed up, leading to hot water coming out of the cold tap.
Malfunctioning mixing valve: A mixing valve controls the temperature of the water coming out of the tap. If the valve is malfunctioning, it can cause hot water to come out of the cold tap.
Problem with the water heater: If the water heater is set to a higher temperature than normal or if it is malfunctioning, it can cause hot water to come out of the cold tap.
Improper plumbing: If the plumbing in your home is not installed correctly, it can cause hot and cold water to mix, leading to hot water coming out of the cold tap.

If your unit was working fine until recently, there are a few possible causes for the change:

Changes in water pressure: If the water pressure in your home has changed, it can affect the performance of the mixing valve and cause hot water to come out of the cold tap.

Failure of the mixing valve: Mixing valves can wear out over time, leading to a failure and causing hot water to come out of the cold tap.

Sediment buildup in the water heater: Over time, sediment can build up in the bottom of the water heater, affecting the performance of the heater and causing hot water to come out of the cold tap.

Leaks in the plumbing system: Leaks in the plumbing system can cause changes in water pressure and can also allow hot and cold water to mix, leading to hot water coming out of the cold tap.

In any case, it is best to have a plumber diagnose the issue to determine the cause and recommend an appropriate solution.