Are Under Sink Filters for Hot Water Too? (How to Sort It) | Water Filter Geek (2024)

Under sink filters work for cold water, but do they work for hot water too, like I know it seems kinda straightforward, but I struggled to find an answer.

So I thought it would be good to share.

There are many things that an under sink water filter is capable of eliminating from your water.

Truly, what these devices are able to do in providing you with fresh water is quite astounding. But, since they hook up to your cold water line, you might wonder what happens with hot water.

Are Under Sink Filters for Hot Water Too? No, standard under sink water filters connect to your cold water line with a T-valve, saddle valve, or directly to the hose. Using hot water in an under sink water filter can diminish the filtration capacity and cause damage to your system.

While this can be seemingly disappointing, there are still plenty of ways to enjoy hot filtered water, even if the under sink water filter is not designed to withstand higher water temperatures.

There are obviously methods of heating water that has already been filtered that would require a bit of maneuvering.

However, fortunately for you, there are easier ways to have hot filtered water. Let’s take a closer look.

How Do Under Sink Water Filters Work?

Are Under Sink Filters for Hot Water Too? (How to Sort It) | Water Filter Geek (1)

Before we can take a closer look at how to get hot water using your under sink water filter, it is important to understand the basics of how an under sink water filter can work.

Along with this, while there are many different models of under sink water filters, they all follow relatively standard methods to provide you with the perfect water filtration system setup in your home.

Of course, the various types of designs and technology that they use will shift from one filtration system to the next, but they typically work following the same general concept.

So, how do under sink water filters work? First, it is connected to your cold water line, either through a T-Valve, saddle valve, or a direct connection to the hose. The water runs through the pipe, enters the water filter, and is pushed through various stages of filtration.

Then, it is reserved in a tank or spouted immediately through the faucet.

Depending on the model that you use, there will be a different number of filtration stages that are most typically associated with the number of filters that the water will have to pass through before being made available for consumption.

While some under sink water filters (one of my fav brands )directly connect to your pre-existing faucet, others (and the majority) will require the installation of a faucet that they come with. This should not be too difficult to install, as most sinks will already have a hole that this can pop through.

But, it is important to note that you might have to place another faucet next to the one that already sits in your sink.

Of course, one of the main points to note here is that the under sink water filter is to be connected to your cold water line.

This supply of water will run seamlessly through your water filter without causing any damage, and your resulting water will be filtered just as the filtration system description said that it would be.

Can You Get Hot Water from an Under Sink Water Filter?

So, you have got your cold water streaming from the under sink water filter as it is connected to the cold water line. If your under sink water filter has a tank, then you can expect this water to sit cold to room temperature as well.

But, what happens if you are looking for filtered water that is also hot?

Can you get hot water from an under sink water filter? Yes, there are ways to get hot water that is also filtered, but it will have come from an exterior connection source such as an instant hot water heater (link to Amazon) or another device. You can also fill a large basin of filtered water and heat it over a stove or another source, but this method is not often preferred.

After all, most of the time, when you are looking to use hot water that is coming from your sink, you are hoping for an instantaneously hot supply rather than having to use a second step to make the water hot in the first place.

For example, if you are washing your dishes in the kitchen sink, you likely want to use your filtered water supply, but you will need this supply to be hot in order to clean the dishes sanitarily. So, how do you make this happen?

You can use a large supply of the cool to cold water that comes from the under sink water filter and heat it over a stovetop or another source.

But, since this method requires an additional step to reaping the benefits of the filtered water, it can be quite discouraging for many users.

After all, washing the dishes is not a chore that many people enjoy doing, and it will be much less desirable if you have to take this additional step to make it happen.

With that said, one of the best ways to get hot water from an under sink water filter (so that your water is both filtered and instantaneously hot) is to use an instant hot water heater.

This can be connected directly to your water line or to the water filter (depending on the model) so that the faucet can deliver hot or cold water.

This type of machine often requires some type of power source, so you will want to pay attention to the installation requirements.

But, since it is able to provide you with hot water that has also been filtered, it is a game changer. Without this type of device, you are limited to the cool or cold water that comes from your under sink water filter.

Why Can’t You Connect Your Under Sink Water Filter to the Hot Water Line?

As you begin to more concretely explore your options for receiving a hot water supply that has also been run through your under sink water filter, you might grow frustrated (or even just curious) about not being able to use the hot water line as a connection instead.

After all, water is water, right? Wrong.

So, why can’t you connect your under sink water filter to the hot water line? Under sink water filters are designed to be connected to the cold water line.

Various reactions and filtration processes that are achieved in the water filtration system require a cooler temperature. Hot temperatures, like that from the hot water line, can ruin the filtration process and the system components.

Just because the water has the same type of contaminants and will require the same filtration process does not mean that water can be run through your under sink water filter at any system.

Are Under Sink Filters for Hot Water Too? (How to Sort It) | Water Filter Geek (2)

Many under sink water filters even come with maximum temperatures that they can be used with.

However, it is important to remember that this is the temperature maximum, not the temperature recommended for standard use. Instead, you will likely find that the temperature for standard use is much lower.

As you review how the under sink water filters are connected and work, you can understand this a bit more clearly. The filtered water is to pass through various stages of filtration.

Since some filters use an ion exchange, a carbon filter, or another type of filtration, these can be influenced by the temperature of the water. If they are so influenced, then you could run the risk of the water not being entirely filtered as you would otherwise expect.

Finally, you also have to consider the materials that the under sink water filter is made from. While most can withstand hot temperatures on their plastic components and other connection devices, the filters themselves can become damaged at high temperatures.

So, if you feel like running the risk of damaging the filters and destroying how the system works, then sure, go ahead and try it with hot water.

However, if you prefer to take good care of your under sink water filter system, then avoid using it with hot water. Instead, seek to install an instant hot water heater or another device that can provide you with the hot and filtered water that you seek.

Are Under Sink Filters for Hot Water Too? (How to Sort It) | Water Filter Geek (2024)


Are Under Sink Filters for Hot Water Too? (How to Sort It) | Water Filter Geek? ›

The system only filters the cold water that gets to the separate faucet mounted on the sink. The water – cold and hot – that gets to the faucet remains unfiltered.

Do under-sink filters filter hot water? ›

The system only filters the cold water that gets to the separate faucet mounted on the sink. The water – cold and hot – that gets to the faucet remains unfiltered.

Can water filters be used on hot water? ›® is your source for water filters for hot water use. Using cold water filters in hot water could really cause problems. We offer these filters for higher temperatures so that you can safely filter your hot water line. Whatever temperature or pressure you need, these filter systems can help!

Are under the sink water filters worth it? ›

Are Under-Sink Water Filters Worth It? Most clean water experts agree: If you can afford an under-sink filter, it's worth owning one. “If you're a heavy user of a water filter pitcher, consider an upgrade to an under-sink filter,” says Paul Lewin, founder of Home Water Research.

What are the disadvantages of under-sink water purifier? ›

What Are the Cons of Under-Sink Water Filters? Because an under-sink water filter is a point-of-use system, it'll only remove contaminants at the tap where it's installed. Also, even though it's a pretty simple install, it's still not as easy as some countertop water filters.

Does hot water filter better than cold water? ›

Hot water also dissolves contaminants in pipes faster than cold water.

Does hot water filter better? ›

But even though it is much more common to have a kettle at home, instead of water filter, this should not make you choose boiled water vs filtered water. While it does disinfect pollutants and kill bacteria, it does not remove them. In addition, boiling water will not remove heavy metals or dissolved solids.

Why not filter hot water? ›

Risk of Chemical Contamination

Lead and zinc (commonly found in water pipes) are more soluble in hot water than in cold water. So when you run hot water through the pipes, lead and zinc are much more likely to leach into the water coming out of the faucet.

How long does a hot water filter last? ›

Most water heater filters need replacing annually. A scale-net or TAC product could last three to five years depending on how much water goes through it and how much hardness you have in the water supply.

Which under-sink water filter removes most contaminants? ›

If you're in the market for one of the best under-sink water filters, look no further than the Aquasana AQ-5300. It uses a two-stage filtration system to remove over 99.99% of contaminants like lead, chlorine, rust and volatile organic compounds, all while improving the odor and taste of your water.

How long do under-sink filters last? ›

Filters in residential settings should be changed every 6 to 12 months. Reverse osmosis, membranes, and additional alkalisers only need to be changed ever 2 years or 4 years, respectively.

Which is better under-sink or over sink water purifier? ›

The only difference between under- the- counter and wall-mounted RO water purifiers is the installation and their look. Under-the- Counter water purifiers use the latest purification techniques to purify the water and make it suitable for consumption.

What are the cons of water filters? ›

The Cons of a Water Filtration System:
  • Speaking of cost, initial installation is more expensive than other filtration methods. ...
  • You can't pick and choose what gets filtered. ...
  • Fluoride and your teeth: If you choose a whole house water filtration system that removes ALL chemicals, you will also be removing fluoride.
Apr 12, 2019

Should I buy a water filter or just buy water? ›

Filter water vs. bottled water. Although both filtered water and bottled water can provide healthier, better-tasting water, the cost-effectiveness and smaller environmental impact of filtered water beats out bottled water at every turn.

What is the most effective type of water filter? ›

Reverse osmosis filters are top of the line for removing a large percentage of contaminants out of the water, potentially including dangerous waterborne bacteria. The filters work by pushing water through the reverse osmosis membrane using pressure.

Is it better to wash clothes in cold or hot water? ›

Is it better to wash clothes in cold or hot water? Cold water washing can actually be more effective than washing clothes in warm or hot water. Hot water can set stains into the fabric, making them more challenging to remove. Cold water is also gentler on fabric, meaning that it is less likely to damage your clothing.

Is it better to drink boiled water or tap water? ›

If you don't have safe bottled water, you should boil your water to make it safe to drink. Boiling is the surest method to kill disease-causing germs, including viruses, bacteria, and parasites. adding a pinch of salt for each quart or liter of boiled water.

What is the healthiest way to filter tap water? ›

It is best to use a point-of-entry filter system (where your water pipe enters your house), or whole-house filter system, for VOCs because they provide safe water for bathing and cleaning, as well as for cooking and drinking. Activated carbon filters can remove some VOCs.

Is boiled tap water better than filtered water? ›

Boiled Water Vs Filtered Water: Which Is Best? The overwhelming conclusion is that filtered water trumps boiled water. Boiling water isn't enough to completely purify the water because it leaves harmful contaminants such as lead and chlorine in there.

How often do you need to change your hot water filter? ›

To maintain the best quality and reliability of your whole house water filter, it is recommended that you change it every three to six months. This helps to keep the water free from impurities and contaminants that can be harmful to your health, your home's plumbing system, and your appliances.

Is it bad to drink hot sink water? ›

We do NOT recommend using hot water from any tap for either direct consumption or food or beverage preparation. This is because hot water can dissolve contaminants more quickly than cold water and hot water systems (tanks, boilers, pipes, etc.)

What happens if you run hot water through a PUR filter? ›

Running hot water through the filters will decrease the effectiveness of the filter.

What happens when you use a water filter too long? ›

Your filter can break down over time, meaning it will no longer be able to filter out the contaminants in your water. If you don't change this before too long, these harmful chemicals and organisms could end up back inside of your home - which defeats the whole purpose of having a water filter.

How do I know if my water filter needs replacing? ›

Here are some indicators that your water filter needs to be replaced:
  1. water tastes like tap.
  2. ice tastes bad.
  3. water or ice smells bad.
  4. water pressure from the dispenser is low.
  5. water filter alert beeps or changes color.

What happens when water filters go bad? ›

Depending on your filter type, after 2 months, 6 months or 6 years, your filter could be covered in bacteria, rendering it unable to perform up to optimal spec, and turning it into a petri dish for all other contaminants to thrive, and those very contaminants that you tried to prevent from entering your house will be ...

Should I leave water dispenser on all the time? ›

While every water cooler is designed to be left plugged in and switched on 24/7 if you need them to be, it's not that energy-efficient to do so – unless it's in use 24/7. So to keep you eco-friendly and save money, it's best to switch the cooler off at the wall at the end of each day.

Can you run hot water through a faucet filter? ›

Most filter installations include a way to toggle between using the filter and using the regular tap, but if you accidentally run hot tap water through the filter, it can be damaged. If these drawbacks deter you from choosing a faucet-mounted filter, an under-sink filter may be a better option.

Do hot water dispensers use a lot of electricity? ›

Water boiler vs electric kettle

While the energy usage to heat the same volume of water is the same, the main difference is that an electric kettle uses a large amount of electricity for a short amount of time and a hot water dispenser uses a small amount of electricity for a large amount of time.

Which water filter removes the most toxins? ›

Michael shares that the healthiest way to filter tap water is by using a reverse osmosis filtration system. "Reverse osmosis is a type of water filtration system that is capable of removing nearly all contaminants from tap water, including bacteria, viruses, and other harmful chemicals," he explains.

Are all under sink water filters the same? ›

However, not all under-sink water filters work in exactly the same way. To address taste, odor or appearance issues as well as specific contaminants like heavy metals and lead, it's best to consider reverse osmosis under-sink systems.

Which water filter removes the most minerals? ›

Reverse Osmosis Remove Minerals. Reverse Osmosis (RO) removed more than 90-99.99% of all the contaminants including minerals from the drinking water supply (see Figure 1). RO removes minerals because they have larger molecules than water.

How do I choose a water filtration system? ›

What to Look For in a Water Filtration System
  1. Point of Use / Point of Entry. Point of Use or undersink filtration systems filter your water where you use it. ...
  2. Contaminants Reduced. ...
  3. Dedicated Filtered Water Faucet. ...
  4. Types of Filters and Filter-less Systems. ...
  5. Filter Change Indicator Light. ...
  6. Working with Water Softener Systems.

What is the difference between under sink water filter and water dispenser? ›

Put simply, the main difference between a filtered water dispenser and a water filtered system is the level of protection the two provide. A water filter system is designed to remove heavy metals and contaminants, offering a higher level of defence.

Do under sink water filters soften water? ›

Water Softener: Conclusion. To recap, a water filtration system is designed to remove toxic contaminants like lead, chlorine, and carcinogens that are commonly found in Phoenix's tap water. Water filters do not, however, soften your water.

Is sink water clean enough to drink? ›

The regulations mean there are still pollutants found in tap water. While it's not technically bad for your health to drink sink water, it's better to drink filtered water to achieve your daily hydration.

Do under sink water filters remove bacteria? ›

Will a water filter remove bacteria? Only a reverse osmosis water filtration system will effectively remove harmful bacteria. The simplest way to remove harmful bacteria is to disinfect the water by chlorination or by ultraviolet radiation.

Is under sink reverse osmosis worth it? ›

Unlike other forms of water filtration, reverse osmosis is considered one of the most all-around effective ways of eliminating water contaminants. Even residential-grade reverse osmosis filters can remove up to 99% of lead, asbestos and 82 other additional contaminants.

Are sink filters worth it? ›

Under-sink water filters can deliver cleaner, better-tasting drinking water the old-fashioned way: from a spout. They're more effective at removing lead, chlorine, and other contaminants than popular refrigerator filters and water filter pitchers.

What is the best under sink water filter for heavy metals? ›

Overall, the best under-sink water filter is the high-performance Aquasana 3-Stage Under Sink Water Filter System. The three-step filtration system won't break the bank but it doesn't sacrifice quality, either. This system works to eliminate sediment, dirt, rust, and heavy metals such as lead, copper, and mercury.

What are the disadvantages of under sink water purifier? ›

What Are the Cons of Under-Sink Water Filters? Because an under-sink water filter is a point-of-use system, it'll only remove contaminants at the tap where it's installed. Also, even though it's a pretty simple install, it's still not as easy as some countertop water filters.

What are the common problems in filters? ›

Frequent filter replacement, contaminated product, analytical test failures, and sub par flow performance are all symptoms of 3 basic filter problems. Corrosive fluids may attack the filter, causing damage and eventual failure of the filter element.

Should you filter tap water? ›

The levels of chlorine in the drinking water are non-toxic, so you may not need a filter. However, consumption over time may have health consequences.

Does reverse osmosis work with hot water? ›

Instant Hot, Cold or Both!

You no longer have to settle for one temperature of water either. When paired with a dual temperature reverse osmosis faucet, you can combine room temperature, instant hot, and instant cold water.

Do carbon filters work with hot water? ›

It's also important that activated carbon filters are used with cold water, which makes them more effective than with warm water – and too much heat is a big no-no, as when hot water flows through the system, it can damage the media.

How can you tell if hot water is cold under the sink? ›

Sink faucets.

Two shut off knobs can be found under the sink. The left one is for the hot water and the right is for cold. Some utility room sinks may only be plumbed for cold water, in which case there will be only one knob.

What happens if you accidentally run hot water through a PUR filter? ›

Running hot water through the filters will decrease the effectiveness of the filter.

How often do you need to change the filter on a hot water tap? ›

Manufacturers will recommend you change the filter on your boiling water tap every 6 months, but this number will vary depending on the tap.

Why can't you drink reverse osmosis water? ›

According to the World Health Organization, low mineral (TDS) drinking water produced by reverse osmosis or distillation is not suitable for long term human consumption and in fact, can create negative health effects to those consuming it. This lack of minerals may also impact the taste negatively for many people.

Is it better to drink tap water or reverse osmosis water? ›

If you are not sure is reverse osmosis safe to drink, with reverse osmosis water you will be exposed to fewer contaminants than drinking unfiltered tap water. Reverse osmosis itself is effective at removing or reducing the following contaminants commonly found in tap water: Protozoa such as Giardia and Cryptosporidium.

What Cannot be filtered by reverse osmosis? ›

Reverse osmosis units do not effectively remove most organic compounds, bacterial microorganisms, chlorine by-products, or dissolved gases like carbon dioxide, methane, and radon.

What are the disadvantages of activated carbon water filter? ›

Disadvantages of Activated Carbon Filtration

Some of the setbacks of activated carbon filtration are: Can't remove all contaminants: Activated carbon is highly effective at removing a set group of contaminants, but it can't be used to completely purify air and water.

What happens if you dont change a carbon water filter? ›

Filters Will become Blocked

If you do not change your water filter on time, it will start to get blocked. When this happens, there is no way for the contaminants in your drinking water to be filtered out and removed from your home - meaning you're going to ingest them all instead!

Is it OK to drink the carbon from water filters? ›

The black dust from a water filter might look unappealing, but it's harmless. Manufacturing activated carbon is safe for human consumption, and it isn't regulated by the EPA. This means there's no maximum amount of carbon we can consume that's deemed “unsafe”.

Should hot water be left or right under sink? ›

Cold water should always be on the right side of the faucet and hot on the left. This is an industry standard throughout North America and applies to single lever as well as dual faucets.

Should hot tap be on left or right? ›

On the LEFT – which is an international standard. Hot Left, Cold Right.

Why are there 3 valves under my sink? ›

Under kitchen sinks, there will typically be three shut off valves. The two uppermost valves will be the hot and cold valves for the sink faucet. The lower valve is for the dishwasher. Conventionally, these valves would connect to the faucet in the same way as bathroom valves/faucets with replaceable supply lines.


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