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Siphon Jet vs. Pressure Assist? Which Flushing Is Better?

Siphon Jet vs. Pressure Assist? Which Flushing Is Better?

In the world of toilets there are a host of options and upgrades that make the old days of the gravity-assisted toilet an unpleasant memory. Since the 1980’s there have been substantial leaps and bounds made in the world of toilets.

Which flushing system is better, siphon-jet, or pressure-assisted? Pressure-assisted toilets produce a more forceful flush, which leads to cleaner waste disposal. The pressure-assisted toilet operates with a louder flush but almost zero clogging.

Deciding between a siphon-jet and pressure-assisted toilet can be a daunting task. Read on to learn about the advantages and disadvantages of both siphon-jet and pressure-assisted toilets.

Types of Toilets

If there’s one thing you learn when doing a bathroom refit is that there are two kinds of toilets:

  • Siphon Jet
  • Pressure Assist

A siphon jet, or a gravity-assisted toilet, uses water from the tank to create a vacuum in the s-bend of the toilet. This vacuum drags waste down the tube and away into the septic or sewer system.

A pressure-assist toilet is easier to spot because it will have a smaller water tank on the back. In place of just water in the tank, these types have a small pressure pump inside. This creates a more powerful flush and uses less water.

Which is better? That’s a question that has sparked quite the debate in hardware stores and online message boards since the internet began.

Pressure Assist Toilet

The water shortage in 1984 led to some exciting developments in water-related appliances. At the time, gravity-fed toilets worked on five gallons per flush. With the invention of the pressure-assist toilet, that number dropped down to 1.6 gallons per flush. Some other advantages of a pressure-assist toilet are:

  • Bill Rebates Offered – There are certain areas in the country where the utilities board will give you money back every month to use a pressure-assisted toilet.
  • Water Usage – The pressure-assisted toilet uses between 1 and 1.3 gallons. In states like California, where there are drought issues, saving water is a huge factor in buying a toilet.
  • Great For Old Homes – These toilets work well with old plumbing. If you are renovating an older home, these toilets save you the trouble of having to replace the plumbing.
  • Fewer Parts – The mechanical system in a pressure-assisted toilet is quite simple. The lack of many moving parts means that there is less that can go wrong, which saves you time and money.
  • Less Condensation – In tropical climates, where it is humid, the water inside a regular gravity-assisted tank will sweat. Sweaty tanks can produce unwelcome staining and deterioration in the unit. The unique design of a pressure-assisted toilet means that there are essentially two tanks in the toilet, which protects from condensation build-up.
  • Fewer Clogs – The power provided by the pump means there will be less clogging. The main draw of the pressure-assisted toilet is the lack of clogging. When the pump forces water into the chamber, all waste is eliminated cleanly and quickly.

The pressure-assisted toilet does have some disadvantages they are:

  • No Conversion – There is no way to convert a pressure-assisted to a gravity-assisted toilet. If the pump does fail, you would have to replace the whole system.
  • Tough Handle – The handle on a pressure-assisted toilet can be hard to push down. If there are kids in the home, a stiff handle makes them uneasy with the bathroom.
  • Ugly – Some people don’t like the way these toilets look. Aesthetics in the bathroom are a critical factor for some people. The lack of or smaller version of a toilet tank can seem strange.
  • Second Flush – When the toilet flushes, it shreds paper and particles can return to the bowl, which means that remnants could stay in the bowl until the next time it is used.
  • Water Pressure – If you have a home with low water pressure, the 30lbs of pressure required to work the pump may not occur. What good is a toilet if it doesn’t flush?
  • More Expensive – The initial cost of a pressure-assisted toilet can be staggering. Budgeting for one is well worth it but could come with a reasonable amount of sticker shock.
  • Sourcing Parts – Parts for a pressure-assisted toilet can be hard to find. The local hardware store doesn’t keep them on hand because of their rarity.
  • Noise – The biggest problem with these toilets is the noise. When they flush, it sounds like a jet taking off. The extra power comes at a price.

A move towards ‘green’ technology is making pressure-assisted toilets more common. Some new construction apartment buildings require these types of bathrooms in the residences.

Siphonic Jet Toilets

Siphonic-jet toilets are usually defined by their S or P-bend shape and jet inside the bowl. Inside this bend is a trapdoor that allows water in and out. The jet inside the fashioned chamber is the siphonic jet. A siphon-jet on a toilet works like this:

  • Waste enters the toilet and piles to the bottom of the bowl.
  • When you push the handle the siphon jet, a molded pocket in the bottom of the toilet, releases a solid stream of water.
  • The stream of water forces the waste down the s-bend and into the sewer.

You probably have this kind of toilet at home. The commonality of it makes the parts readily available and professionals who can fix it in abundance as well. Siphon jet toilets have several advantages. They are:

  • Water Efficient – The siphonic toilet was a by-product of the innovation in the 1980s. The jet inside the bowl removed waste faster and cleaner than its predecessor.
  • Less Odor – A more substantial water area inside the bowl makes for less smell. The water acts as a barrier between sewer gasses and your home.
  • Less Noise – When you flush a siphon jet toilet, there is much less noise. The pump inside a pressure-assisted toilet is much louder than these models.
  • Cleaner – The primary purpose of the siphon jet is removing large loads of waste more cleanly. Often bowls can be stained with skid marks and particulate. The jet aids in removing these from the container.

For every advantage of using a siphon jet toilet, there is going to be a disadvantage. Some of the most glaring ones are:

  • Large – These toilets usually don’t fit in a smaller bathroom. The jet system requires a more extended base to operate.
  • Clogging – These toilets are notorious cloggers. The S-bend creates a siphon that can be blocked off by excess waste. A plunger nearby is a good idea.
  • Running Tank – If there is a handle in disrepair, the toilet could continuously run, which wastes water. These are a quick repair and can be found in your local hardware store plumbing section.
  • Installation – Replacing an older toilet could mean fitting problems. Measure the area and the toilet while it is still in the store.

Make Your Play

In the end, choosing which toilet works best for you and your situation is up to you. For my money, the pressure-assisted toilet takes it in a walk, and here’s why.

  1. Clogs – A person is never more scared and stressed than when a toilet begins to back up. We’ve all been there, and it can be humiliating. The pump that regulates pressure in the toilet makes that a thing of the past. Sure there could be particles of toilet tissue left behind by the blast of air, but that is a small price to pay.
  2. Water – These can operate on as little as 1.28g per flush. If you are an environmentally conscious person, water conservation could mean the difference. While there are other types of toilets, we will get to that later, and this one is standard and water efficient.
  3. Rarity – The majority of homes have a siphon jet toilet. They are the most popular and therefore the most worked on. While the scarcity of the parts for a pressure-assisted toilet is a real thing, they last forever. Even though it is a rare toilet, the functionality is unmatched.

Rise of The Smart Toilet

In recent years there has been a boom in the bathroom industry. The accessories that you find on any car can now be found in your toilet. Today you can order toilets with add-ons like:

  • Televisions
  • MP3 Players
  • Seat Warmer
  • Foot Warmer

When you are in the market for a new toilet giving a smart toilet, or one of the many accessories, a look wouldn’t be a bad idea.

Most Popular Smart Toilets

Kohler – When it comes to innovation in the bathroom, Kohler does a bang-up job. This pressure-assisted toilet is something straight out of the future. It is a one-piece dual-flush toilet that looks like something that came off the Enterprise. This one features:

  • Smart lid – The lid can be controlled from your computer or cell phone from anywhere. Live in the States and are on a trip to the Bahamas? You can let the seat down! This thing is going to save so many marriages…
  • Dual Flush – Dual Flush is a fresh innovation that allows you to use two different types of flush, depending on the nature of your trip to the bathroom. The first is a tiny flush for water, and the second a larger pressured flush to accommodate extra material.
  • Heated Seat – Like the lid, the heated seats can be controlled via the app. This seat can be set to your specifications and will be ready when you enter the restroom. Talk about convenience.
  • Bidet – The most raved about a piece of this toilet is the bidet. It has several programmable methods and can be contoured to your liking.
  • Night Light – There’s a color-changing bulb inside the tank that will shift colors via the use of the app. This is one of the coolest things I’ve seen in awhile.

TOTO Washlet – The price competitor to Kohler has upped their game. The TOTO Washlet has several neat options that have been cherry-picked by competitors over the years. The highlights are:

  • Pre-mist – The TOTO does something that I’ve never heard of before. It pre-cleans the toilet before you use it. The unit sprays a mist once it recognizes it is about to be in use. This mist makes cleaning up easier.
  • Self-care – There is a self-care option that allows people with disabilities, there’s a mode for most ailments, to get a bit more independence.
  • Self-cleaning – There’s a cool attachment inside the bowl that keeps your toilet clean for the life of the appliance. The pre-mist was just the beginning, and the self-cleaning option makes it a virtually hands-off device.
  • Air deodorizer – The biggest problem with any bathroom is the smell. A handy deodorizer in the tank keeps the unit smelling fresh and clean.

Dyconn Tankless – The newest trend in the smart toilet arena is the tankless option. Like the tankless water heater in your home, this unit heats water as it is needed. Some other cool options are:

  • Smart Bidet – A big hook for this tankless unit is the smart bidet. As mentioned earlier, this unit heats water as is needed. Meaning that the water used to wash your delicate undercarriage is warm and inviting.
  • Seat sensor – The heat sensor that is built into the toilet has an indicator that lets it know when it is in use. For us, that means that the heated seat is continuously on and wasting power. The chips inside inform the computer when it is in and out of use.
  • Dual nozzle – Another draw of the bidet is the dual nozzle system. This system applies two streams of water that can accommodate each member of your family. One uses a more intensive stream while the other has a delicate spray.
  • Cleaning – One of the major draws from this unit is the cleaning. Like the TOTO the Dyconn uses a series of sprays from the bidet to make the unit self-cleaning.

All the Rest

It goes without saying that the types of toilets mentioned in this article aren’t the only ones available. Some other notable types of toilets are:

  • Composting – The practice of composting goes hand in hand with a homesteading or rural setting. The main parts of waste are mainly water and can be filtered. A compost toilet works on this principle:
    • Unlike a regular toilet there are no plumbing attachments.
    • Inside the bowl is a large cylinder. It has openings on the body to release the waste.
    • You process the waste by turning the cylinder and removing the water waste.
    • Under the cylinder is a tray that looks like something from the paint aisle. This is the evaporation chamber. All liquid waste will pool here.
    • The finishing drawer is a drawer that pulls out of the front of the unit. This is where all the compost, which was once waste, will be collected.
  • Port-a-toilet – We have all seen the large multicolored plastic booths that make up a port-a-john. These are mainly for storing and are cleaned daily, if you are lucky, but have a main usage in the construction industry. These are usually serviced by a company but if yours isn’t, emptying it yourself is a simple job. The steps are:
    • Remove the waste bin from the toilet.
    • Make sure the tank is closed off.
    • Find an area suitable for disposing waste.
    • Take off the lid and dump the waste.
    • Replace the cap.
    • Return the waste bin to the toilet.
    • Add water to the tank.
    • Treat the water with included chemicals.

Best Composting Toilets

Nature’s Head – Nature’s Head’s self-contained unit was designed by a couple of ex-sailors. They wanted to make a toilet that was self-contained and could be used in any environment. The fine built inside helps air circulation and clears the air of bad odor.

The main gripe about Nature’s Head is that the plastic is not soft. The seat is also undersized which makes for an uncomfortable pairing. Most buyers say that otherwise the model is easy to install and maintain.

Villa 9215 AC/DC – Boasting the most trouble-free toilet on the market the Villa is a great toilet. The lack of plumbing means that no matter the environment you can safely process waste. The Villa is an expensive, but compact, model of self-contained toilet. The upside to the price tag is an ironclad guarantee on parts and replacement for five years.

STANSPORT Camp Toilet – This nifty little unit is the king of campground toilets. Its small size means that it can be carried and stored virtually everywhere. This is basically an enclosed waste bin with a seat, which is a minimalist’s dream.

You would think with so many light and easy to make parts this would fall apart just as easy, you’d be wrong. There are stories of these toilets outlasting most common camping equipment.

CAMCO Travel Toilet – Camp toilets work just as well as the in-home versions. The CAMCO is a sturdy and super functional unit that is a great addition to any camp. It features a lock in tank and a button that protects against overflow.

CAMCO makes a great budget composting toilet. Their polyethylene shell is durable, and the waste tank is easy to get to and remove.

Learn More

If you are interested, go check out the toilet section on Amazon for any great deals.