Why is There Low Hot Water Pressure in the Bathroom Sink Only?

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Low water pressure in a single faucet can be caused by lots of things. However, the situation only gets worse when the pressure drops only when you use hot water.

But, there’s nothing to be afraid of since this kind of problem is easily fixable and they can’t create many problems when it comes to plumbing.

Anyhow, one of the most common places where using hot water and the water pressure decreases is the bathroom sink. 

Since the bathroom sink is usually a single faucet that means that the problem of low water pressure can be caused by only a few things.

That being said, let’s dig a bit deeper into this problem and see everything that you need to know about it. Let’s start.

Low Hot Water Pressure in the Bathroom Sink Only

Causes of Low Hot Water Pressure in Bathroom Sink 

As we all know, not being able to use hot water in your sink faucet is definitely annoying. The first thing to do is to find what’s causing it and try to fix the problem.

So, in that light, we are going to see the causes of low hot water pressure in bathroom sink only.

1. Shut-Off Valves

The first and possibly the most common thing that can affect your water pressure when it comes to the hot water is the shut-off valve. Namely, there are two shut-off valves beneath the sink in your bathroom and they are regulating the water flow for the sink faucet.

Now, if the valves are not functioning properly, there will be a significant loss of water pressure. However, that doesn’t always have to be the case. But, it’s definitely a good thing to check these valves.

Anyhow, you will need to inspect the shut-off valve for the hot water; that’s usually the one on the right.

So, check if there are any corrosion build-ups or simply anything that would prevent this valve from working properly. If you find that this valve is in bad condition, we suggest that you replace it immediately.

2. Hot Side Faucet Stem

In some cases, the problem is located directly at the faucet.

Namely, if the hot side faucet stem is not functioning properly, the water pressure will definitely drop once you turn on the hot water. This can happen due to the fact that the stem is covered in all sorts of build-ups and debris.

This can create problems and the faucet won’t be able to have normal water pressure when it comes to the hot water. So, you should definitely check the faucet stem for any debris and inspect it.

If you find that there’s nothing wrong with the hot water faucet stem, then the problem is not located there.

On the other hand, if the problem is located there, then simply try to clean everything up which will allow hot water faucet stem to work properly once again.

3. Faulty Aerator

The aerator is not usually the cause of low water pressure when it comes to hot water, but it can definitely create similar problems.

This means that if the aerator is clogged or partially clogged, the whole faucet will lose water pressure, not only hot water.

But, it’s definitely worth mentioning that the aerator is one of the things to check when you are facing low water pressure on a single faucet.

Low Hot Water Pressure in Bathroom Sink

4. Water Heater

Since the water heater is producing hot water that is used in bathrooms, the problem could easily be located there.

Now, the water heater is releasing a certain portion of water under a certain level of pressure – this depends on the water heater. Anyhow, the average water heater is working under no more than 30 PSI of water pressure.

So, if the problem is located at the bathroom sink faucet that could mean that there isn’t any water coming from the water heater to the faucet.

Also, in some cases, the water heater will simply lower the water pressure due to some precautions.

But, the main thing is that there is simply not enough water pressure when it comes to hot water.

This can also happen if the pipe that leads the water from the water heater to the faucet is clogged.

Over time, pipes are usually clogged do to the fact that there are lots of minerals in the water which can create clogs in small places.

What Can You Do to Prevent Low Hot Water Pressure?

Well, in order to prevent this kind of thing from happening, you can always change all the valves on the bathroom sink. However, that would not be necessary if the valves are working fine.

So, we suggest that you take into consideration these few things when it comes to the bathroom sink faucet.

  • Check the aerator from time to time – As one of the main reasons why the water pressure gets significantly low, the aerator should be checked from time to time. This way, you will always stay ahead of the problem and take precaution measures.
  • Inspect water heater – Once you notice even the slightest change in the hot water pressure, you need to immediately check the water heater and see if there are any changes there. The best thing to do is to inspect the temperature and pressure relief valve. That way, you will be one hundred percent certain whether the water heater is the cause of the problem.
  • Clean hot water faucet stem once in a while – Cleaning hot water faucet stem is actually quite important. Now, you don’t have to do it every single day, but, once you notice that there’s something wrong with it, you should definitely clean it.

As we can see, these are a few things that you can do in order to prevent loss of hot water pressure when it comes to the bathroom sink faucet.

Conclusion: Low Hot Water Pressure in Bathroom Sink

All in all, hot water pressure is quite important, no matter what. In that light, dealing with the low water pressure when it comes to hot water should be done immediately, especially for the bathroom sink.

Anyhow, make sure to check everything we listed here in order to know what’s causing low hot water pressure.