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3 Reasons for Hot Water in Your Sink, But Not the Shower

3 Reasons for Hot Water in Your Sink, But Not the Shower

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If you’re suffering from cold showers and yet have hot water in your sink, you don’t have an issue with your tank or a defective dip tube. There are most likely issues with different components of your shower.

There are three reasons your shower has no hot water: the adjustment valve, the thermostatic valve, or the supply pipes. The adjustment valve is simple to fix, taking several minutes. If it isn’t the gauge, the problem is the thermostatic valve or the supply pipes. Then, you will need a plumber.

It is important as a resident to take proper precautions before fixing your shower. Firstly turn the water off in your house. Secondly, place a towel under the faucet to prevent losing small screws.

Why Do I Have Hot Water in My Sink, But Not in My Shower?

There are three reasons for the differences in hot water allocation. Either your anti-scald gauge is set too high in your shower handle, or your shower mixer valve (thermostatic valve) is ruined, old, or clogged. It could also be a problem with the supply pipes, but this isn’t likely, and you will detect sizeable leaks before anything.

Adjusting the handle’s anti-scald device is simple to do, as long as you follow the basic steps and take the necessary precautions. It should be done in under 10 minutes.

If regulating the anti-scalding gage doesn’t produce desired results, you may need to call a plumber to fix your thermostatic valve or address a problem with the supply pipes.

Hiring a plumber is expensive, and if you want to save money, you can replace the thermostatic valve on your own. Be aware that you are dismantling the shower fixture, and extra care and attention to detail are necessitated.

When acquiring a new valve, you’ll need to research the screwdriver or Allen wrench (hex wrench) and get proper advice from retail clerks.

Adjust the Anti-Scalding Device

Anti-scalding valves are safety features that most faucets have and are found in the shower’s handle. It is also referred to as a hot limit stop or a rotational limit stop. Its function is to limit the level of hot water poured out of the faucet by restricting how far the handle moves toward the hot section.

Your home water’s Temperature Danger Zone (TDZ) must be avoided. Bacteria rapidly breed in temperatures between 40 and 140 degrees Fahrenheit. This difference is the TDZ. Therefore your hot water must be set at 140 degrees Fahrenheit. This degree of heat will cause third-degree burns and damage if exposed for longer than six seconds.

The thermostatic shower valves and the anti-scalding device allow you to regulate the temperature to your desire while preventing harmful disease and bacteria (Legionella) from spawning in your water.

To determine if your anti-scalding device is set too high is relatively simple. Firstly, as a precaution, switch your water off. Generally, locating the water valve in your residence is very important. It could be near the water heater, garage, or if you have a basement, check your basement walls. The main valve is outside, buried in a protective box.

Then, once your water is switched off, remove the head, or handle of your shower faucet. Every manufacturer designs their shower handles slightly differently, so you may need a screwdriver or Allen key (Hex wrench) to do this successfully. Place a towel under the handle to capture the small screws. There are basic steps to removing your shower faucet.

Rotate your temperature handle to its maximum setting. Typically, this is a full turn to the left. Remove the handle. Usually, the handle is a decorative plastic covering that will prize off when inserting a small flat head screwdriver under the rim.

It could also have a tab on its side that releases if pushed and lifted. If the handle is held in place by screws, use a small screwdriver, an Allen key/wrench.

Then locate your anti-scalding device. It is a small, probably plastic, adjustment mechanism located immediately within sight after removing the decorative handle. The adjustment gage is a dial or screw, and they are generally pre-installed with the faucet.

Test the water temperature. Turn on the water and place a thermometer within the flow of the water. Then wait for the bar of the thermometer to stop moving.

Following that, adjust the plastic anti-scalding device. To do this, pull the gage forward and then position it to the left if you want your water to be warmer.

Test the temperature again and repeat the process of turning the gage until you have your desired temperature. Once it’s been adjusted to the preferred setting, click the device back in. Reassemble the head.

Adjusting your anti-scalding device is a simple and easy fix. It should not take you longer than several minutes.

The anti-scalding device could be clogged. If this is so, try rinsing the mechanism with pressured water. If this still doesn’t work, buy a new device. The issue with no hot water could be that the device wasn’t calibrated correctly. Turn to adjust.

The Shower Mixer Valve (Thermostatic Valve)

If adjusting the anti-scalding gauge didn’t alter the water temperature, then the problem probably lies with the shower mixing valve. The shower mixing valve is also referred to as a cartridge or a thermostatic valve/cartridge.

Its function is to combine the correct amount of hot and cold water for the shower, preventing scalding. Thermostatic valves are fashioned to maintain both water pressure and temperature. There are thermostatic valves with a gauge that permits users to pre-set their desired temperature.

If the thermostatic cartridge is broken, old, calcified, or ruined, the best solution is to call a plumber. The main reason to call a plumber is that the shower fixture must be dismantled to reach the cartridge. You’ll need a professional to ensure it is done correctly.

The plumber will most likely replace the valve. The valve could be worn through from age and use, especially the O-rings and the rubber parts, which will need to be replaced.

The rubber aspects of the cartridge are continually exposed to high heat. They break down, and little pieces clog the shower. The issues with the valve could be as simple as clogging debris or a natural consequence of use over time.

On a positive note, these parts are inexpensive and not time-consuming to repair. If the valve is clogged, it will only need to be flushed. If it is damaged, replacing it will be relatively affordable.

Replacing the Thermostatic Cartridge – Do It Yourself

If you are resolved to replace the valve yourself, it will take effort, research, and a trip to your Home Depot or hardware store. However, it will be significantly less expensive than hiring a plumber. You’ll need to disassemble the entire handle to reach within the wall of your shower fixture.

Make sure you research what tools you’ll need to unscrew the handle (remember to keep a towel beneath the work area). Once this is done, you’ll see the exposed piping in the wall and the thermostatic valve or cartridge.

Usually, residual water and some debris pour out when dismantling the handle. You can limit the level of water and mess; use a paper plate and assist the water’s natural flow or a towel to soak up the mess.

Take the cartridge to your preferred hardware store. Allow them to advise you on your thermostatic valve, whether it is broken, clogged, or if it wasn’t installed correctly.

If you buy a new valve, it should be affordable. The hardware store’s retail assistants will advise on the size of the valve and additional features you might need to acquire, like a pressure balance. It will be considerably less expensive than hiring a plumber.

Replacing the valve is a simple sequence of reversing the steps. First, place the new pressure balance then the new cartridge or valve. Remember you need the correct measurement of screwdrivers size for the screws.

When acquiring a thermostatic valve and replacing it in your shower, you can pre-set the temperature and the water pressure. There are many advantages to installing a pre-set thermostatic valve.

Benefits of a Pre-Set Thermostatic Valve

A pre-set valve will allot the exact temperature and pressure throughout your shower. It prevents sudden bursts of water and maintains an equal water supply. If another person in your house flushes the toilet or uses a different faucet, this will have absolutely no impact on your shower.

Safety is the primary advantage of a pre-set thermostatic valve. The pre-set valve maintains the precise temperature and pressure of water. A pre-set valve will guarantee the safety of vulnerable residence of your home, like children and the elderly. It also saves water and energy.

There is heightened enjoyment and convenience in a pre-set thermostatic valve. If you stop showering to wash your hair, turning the shower on will automatically release the exact temperature and pressure you are accustomed to. You won’t have to step back or get out of the shower while waiting for the right temperature.

The Supply Pipes of the Shower

It will seldom be that the issue of no hot water will result from your shower’s supply pipes. On the rare occasion that the absence of hot water results from sizeable leaks from broken, disrupted, torn, or fractured piping, these leaks will be obvious and quickly noticed.

There could be an issue with a partially shut valve or faucet incorrectly installed. You might need to adjust that or get an auxiliary water heater. Distance from the water heater could be a factor. The piping will require an inspection of the layout of the hot water pipes.

Plumbers whom residential owners contract frequently install valves in the water lines leading to the bathrooms. It could be that hot water isn’t getting through because of a partially closed valve. If you follow the pipe from the water heater to the bathroom, you’ll come across the valve, and it’ll be in open sight.

You could also come across a temperature regulating valve that plumbers install to prevent scalding water from blasting through. You can adjust the valve with a screw head.

The lack of hot water could be due to cross-over pipes. In the past, before thermostatic valves were invented, contractors had to figure out a way of allowing hot and cold water to flow simultaneously through the shower; their answer was cross-connecting pipes. Today, cross-over pipes are obsolete. However, this may be an issue in an old building.

Corroded pipes are an issue as they influence the amount of water supply and reduce the amount of water pressure. Therefore, hot water will struggle to reach the desired destination as supply is restricted due to corroded pipes.

Galvanized and copper pipes will affect the pressure and temperature, especially as hot water contributes to sediment build-up. If your house is old, then this is probably the cause. You’ll have to replace the piping.

Suppose the plumber discovers that both the anti-scald mechanism and the thermostatic valve function without issues. In that case, they will investigate the supply pipes and the heating tank to uncover the problem. However, if every other faucet has hot water, it won’t be the heating tank.

Other Reasons for Cold Water in the Shower

The plumber will look at the anode rod when inspecting the heating tank. The anode rod is a steel wire covered in aluminum, magnesium or an aluminum/zinc alloy that prevents the heating tank from rusting.

The metal rod runs down the center of the tank, and it is a vital aspect of the tank. If this rod is old, faulty, or worn, there will be sediment build-up- this will prevent hot water from coming through.

If you have an electrical heating system, the elements of that heating system could have burned out. If this is the case, water will be warm for short durations and then not hot at all. It will be hot, only to cool down very quickly.

The cold-water dip tube could have deteriorated in an older heating tank. The dip tube is the conduit transporting cold water into the heating tank. Therefore the cold water will not enter the heating tank; instead, it will go immediately into the hot water pipe feed.

Keep regular vigilance of your thermostat. The temperature must be a constant of 122- and 140-degrees Fahrenheit. If your thermostat isn’t regularly maintained, it will break due to sediment build-up. Flush the heating tank to remedy this.

Final Thoughts

If your shower has hot water, but there is hot water in your sink, and everywhere else throughout the house, the issues lie in different aspects of your shower, not in the heating tank or a defective dip tube. Remember, before you address the problem, switch off the water.

You most likely need to adjust the anti-scalding device; this is a simple task that can be completed in several minutes. If there isn’t hot water, then the issue is with the cartridge.

Contact a plumber to ensure the task is done properly. If it is too expensive, you can replace it on your own. Rarely will the issue be the supply pipes.

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