Lukewarm water from cold tap

Lukewarm water from cold tap. Most people do not think before opening the tap to wash their hands. That’s why it becomes very irritating to see lukewarm water coming from the cold taps.

Don’t waste time fixing this problem when hot water comes from your cold taps. Always try to address the trouble immediately because hot water can damage the skin of anybody in the home.

There could be a number of culprits responsible for hot water from the cold faucet. However, the most usual reason behind this issue is water pipes are closely installed with each other, wrong installation of heat traps, heating effects, and sometimes extra water pressure.

It is suggested that you ensure to tighten all the nuts near the cold and hot water taps. If you tighten all the bolts, then hot water will not mix with cold water tap.

If you are here, it means you are having hot water coming from a cold tap issue; then read this guide to troubleshoot this problem.

Lukewarm water from cold tap

If you are washing your hands under a cold tap but suddenly you feel that warm water starts coming from your cold tap, then do not ignore this because it happens due to something wrong with cold and hot water taps.

Immediately, check both taps connections below the bathroom sink to ensure that what is the reason behind this sudden change in water temperature from cold to hot.

Sometimes, the hot water valve remains open slightly, due to which hot water mix with the cold water tap, so check the hot water valve under the sink and close it properly. Let’s some major causes and their solutions for lukewarm water coming from cold taps.

Cold pipes flowing through the hot area

cold pipes flowing through the hot area

When you construct your home, the most important thing is to install the plumbing lines in the proper manner.

If cold water pipes flow through a hot area, such as a kitchen, or an attic, then the cold water coming from these pipes heats up due to running through a hot area.

So, always take care of this point when you install the pipelines in the home, but if you have already installed the pipes and facing this issue, then change the place of the water pipes and shift them to another part of the home to get cold water in the summer season.

Obviously, you can not do this unless you are a certified professional so hire a plumber to move the cold water pipes to other parts of the home.

Replace the pipes

It’s a fact that the water gets hot in copper pipes quickly compared with PEX water pipes, so if you are having the hot water issue coming from cold pipes, then you can also change your copper pipes’ PEX water pipes to get the cold water in hot summer.

Poor Heat Trap Install

poor heat trap install

When you construct your new home, the most important thing to look upon is plumbing sewerage pipes and ensuring that the heat trap is set in the water heating inlet.

Apart from that, the warm water inside a water heater will drain away and combine with the cold water lines to warm the cold water faucet.

Water source

Sometimes there is no issue with the water pipes, but the hot water also starts coming cols the faucet due to the water source.

Usually, we use well water, city water, or sometimes rainwater in our daily lives for cooking, food, and washing purposes.

Summer weather does not heat up the city water in water lines. But, if you use fresh well water, it turns hot in hot summer weather.

Change cartridge

change cartridge

Nowadays, cartridges are installed in modern taps to divert water.

Sad to say, if the faucet cartridge becomes faulty or broken, the issue generates due to this is warm water coming from cold taps. Sometimes, this hot water burns the hands.

So, inspect the faucet cartridge, and if you find it is damaged, then it’s time to replace the cartridge to save older people and children from sudden hot water coming from the cold taps.

If you have some basic plumbing skills, then there is no need to hire a plumber because you just need to unscrew the faucet and pull out the cartridge from inside.

Change the faucet cartridge but ensure to match the cartridge with your faucet brand; otherwise, it will not properly fit inside the faucet.

Too much water pressure

It is crucial to control the water pressure in home plumbing through a water regulator. High water pressure is hazardous for home appliances and faucets in the home.

If there is too high of water pressure in the water pipes, the hot water mixes with cold water, and warm water starts coming from cold taps, so check your water pressure through a water regulator device and control it to save your home’s plumbing.

Faulty thermostat

faulty thermostat

If you have a water tank in your home to store the water, the thermostat is immersed in controlling the water pressure.

This thermostat can become faulty and starts malfunctioning over time, due to which the water is overheated in the expansion tank.

The hot water flows into the cold pipes and warms the water, so check your thermostat, and if it is damaged or broken, then replace it with a new thermostat device to control the hot water in the expansion tank.

Heating effect

If you have installed copper pipes in your home plumbing, then do not fix hot water and cold water closely with each other because the hot water pipe can heat the cold water pipe, due to which warm water starts coming from the cold faucets.

It happens because the heat is transferred from copper pipes to make the cold faucet water very hot.

However, this heating effect is short-term, so always install the pipes at a slight distance so that the heating effect does not warm the cold water faucet.

Cross connection

cross connection

Hot water coming from the cold faucet is also because of a cross-connection between the cold and hot water lines.

So, ensure that both hot water and cold pipes do not cross each other in the plumbing system; otherwise, the hot water will flow through cold pipes or vice versa.

Both pipes usually cross-connect to each other in cartridges in single-lever faucets. It mostly occurs in two or three single-lever faucets.

Hire a certified professional to change the cross-connection faucet settings so that the cold water does not heat up from hot water pipes.


The final words of this article are it is an enormous problem to notice hot water starts coming from the cold tap and then immediately check the water connections under the sink.

Replace your copper pipes with PEX pipes if you have enough budget because the heating effect and too much water pressure are the most common causes of this problem.

I am hopeful this troubleshooting guide has helped you to point out your issue; if there is a minor problem, then you can fix it by yourself with basic plumbing skills but if you want to replace or repair water pipes, then hire a plumber for this maintenance.

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