View Full Version : Are All Pressure Assist Toilet Noisy?

05-26-2007, 11:31 AM
I am trying to find a toilet that is to be used for the second floor. However underneath the 2nd floor bathroom is the guest room.
One criteria is an efficient toilet which makes pressure assist a top choice. However, I heard that it is noisy...

Are All Pressure Assist Toilet Noisy?:confused:
What brands are not that loud when flushing?:confused:

05-26-2007, 03:33 PM
All pressure assist toilets I've seen are noisey. Not all pressure assist toilet work all that well. Some are known to shread things, and leave little bits floating in the bowl when finished, which doesn't help, since you then have to flush again, wasting the water you were supposed to save.

On Terry's home page are links to some independent tests on toilet performance. Many of the best flushing toilets are not pressure assist. It's all in the quality of the engineering. A pressure assist also requires more expensive parts that are not available everywhere when it eventually needs service.

Personally, I'd stay away from them and use one of the highly rated gravity flush toilets. I've had good luck with the Toto toilets I've bought, they are quiet and work well; plus, they've gotten great reviews.

Mad Plumber
05-26-2007, 05:30 PM
Who cares if it's noisey. Put it in a warehouse and flush it there.
Ther not taht noisey anywha. Maybe cyan hear them from 65 gett away.
but you shoudn't nt that clo9se anyway.

05-26-2007, 05:50 PM
They are noisy just by definition as to how they flush. In most cases the water is at 60 psi or more when the flush starts, compared to 1 psi or so for a conventional toilet.

05-28-2007, 08:08 PM
:o Help! I am in the midst of remodeling a bathroom. It sits between my 4 yr olds room and the master bedroom. The problem is the 4 yr old wakes at the slightest noise and obviously we need to flush sometimes. We need to replace the Kohler Wellworth as it is not strong enough for the waste that is produced in our home. What is a good strong toilet that is quiet?:

05-28-2007, 08:15 PM
no solution in sight, AFAIK. Eliminating the flush valve is a good step, but what to put next is hard to know.

Bowl Flush noise, and then drain flow noise, are not easy to measure with even the best instrumentation, and way way harder to describe. Any flush down toilet will be good; someone may like one or another, but all you will get is anecdotal information.

In a year from now he'll be that much older, and at some point he'll sleep through anything.

In the meantime, after the new toilet, if that doesn't help enough, you either adjust living habits or you rebuild: solid walls and cast iron drains.


05-29-2007, 08:13 AM
... not strong enough for the waste that is produced in our home. What is a good strong toilet that is quiet?: I'll bet your water supply pipes were too small to produce the flow that the Weelworth needed. The pipe has to be large to let any flush valve work as designed. If true, then you can conclude that your waste is not the problem. Any flush down that has a smooth noise when flushed will be fine for your situation.


05-29-2007, 09:27 AM
The Wellworth is one of the poor flushers out there. I remove them all the time.

There isn't much that is super quiet anymore. The ones in the past took over nine gallons to do it quietly.

I installed a standard height Drake toilet at my daughters home, and it seems pretty quiet though. She has kids, and they haven't plugged it yet in 1.5 years.

05-29-2007, 10:02 AM
There is an independent joint testing done by USA and Canada for Maximum Performance of toilet fixtures for pressure assist, gravity,etc.

However I have not seen any noise/acoustic testing for toilets... Even in the manufacturers technical specification/manual, there is no mention of such.
I know its kinda too detailed for independent testers to take there time and do this... But there are situations like when you have an elderly, a baby, live in an multilevel apartment where noise level can really be an important issue.

Is there a website which makes such noise testing?:confused:

05-29-2007, 10:14 AM
I found one toilet that is dual flush and pressure assist and has the highest maximum performance rating of (1000) ...
Zurn Z5572 EcoVantage EL ADA...

I contacted the manufacturer with regards to the noise level... Here is his reply...

"Our Z5562 dual flush pressure assist toilet is quieter than most pressure assist models in the market today. Many manufacturers vary on how noise (Db) ratings are tested / measured on toilets, so it is very difficult to measure one toilet against another based on their published noise ratings.

On average, our EcoVantage series of pressure assist toilets have equal to or lower Db ratings than most low consumption gravity operated toilets in the market today."

The bottomline is it looks promising because of its performance and water saver at the same time...However, the claim that it is equal or lower noise than the conventional gravity operated toilets is still a claim...

In its website, it says it is a commercial toilet... Has anyone seen or have this in there property?:confused:

05-29-2007, 10:14 AM
MaP testing
And the testing you mention, doesn't look into things like

Quality control
Bowl cleaning
Ease of Assembly
Ease of repair and cost of repair
Noise levels
Style and appearance
Depth of water in bowl
Total dimensions (some round bowls are longer that others elongated bowls)

05-29-2007, 10:37 AM
So far I have this partial list of Pressure Assist with a high maximum performance rating... (I rank it based on decreasing Maximum performance done by veric)

1. Zurn Z5572 Ecovantage EL ADA (http://www.zurn.com/pages/catalog.asp?ProductGroupID=148&OperationID=19)
Characteristic:Two piece, Elongated, Pressure Assist, Dual Flush, ADA compliant, 2 1/8" trapway
Maximum Performance rating: 1000
a. "In our experience, the some of the absolute quietest toilets in the industry flushes at around 70 db… The high range for noise ratings in toilets are over 110+ db. Our EcoVantage pressure assist toilets average in the 80s for a decibel level." ---Zurn representative
Noise Level:

2. Mansfield EcoQuantum 148-119RHCL (http://mansfieldplumbing.com/v2/product00.html)
Characteristic: Two piece, Elongated, Pressure Assist, Dual Flush, ADA compliant, 2" trapway
Maximum performance rating: 925
Noise Level:

3. Gerber Ultra Dual Flush DF 21-324 (http://www.gerberonline.com/Catalog.aspx?categoryID=2202&itemID=3512)
Characteristic: Two piece, Elongated, Pressure Assist, Dual Flush, ADA compliant, 3 1/8" trapway
Maximum Performance rating: 800
Noise Level:

4. Gerber Maurice One piece Pressure Assist 21-012 (http://www.gerberonline.com/Catalog.aspx?categoryID=415&itemID=2037)
Characteristic: One piece, Elongated, Pressure Assist, 3 1/8" trapway
Maximum Performance: (no rating published but Gerber have 800 or + rating)
Noise Level:

I made the following assumption: 1. The larger the trapway diameter, the less likely to clog; 2. One piece toilet is easier to clean. 3. Performance can be objectively compared using stats from independent testers.; 4. Dual Flush saves the most water compared to other types; 5. Pressure assist makes the toilet bowl side cleaner coz it pushes down the water from the rim rather than "vacuum" it in from under like the gravity fed; 6. Pressure assist will be noisy??? coz of the high pressure; 7. ADA compliant is better coz the bowl height is right so it won't be a "pain" on your knees; 8. Elongated is better so it is easier for the guys to "Aim"; 9. Cost of repair????I dont know yet; 10. Longetivity??? I don't know yet

P.S. I am not affiliated in anyway with any of the manufacturer... Just a homeowner doing a bathroom remodel and some research... So I am listing facts based on reports, testing and manufacturer specs.

I will update the list so it can be a summary...
I am emailing the manufacturers for added info...
Please do include comments, corrections or personal experience on the list of toilet like noise level, repair, ease to clean...etc.

and if you have a toilet model which you can add, please do post...

05-29-2007, 11:55 AM
Trapways on the pressure assist toilets are about 2" at the outlet.
Many of the Gerber are 1-7/8"

It doesn't matter if you have a large end on a funnel, it still needs to squeeze out of the end.

Pressure assist toilets are mainly siphon jet, with just a little bowl wash in most cases.

All toilets rated at 1.6 gallons use about 1.6 gallons.
Meaning, there is not really an advantage either way from going pressure assist, or using a large flapper.
Some pressure assist bowls take the paper and poop, break it up, and will leave little bits and shreds in the bowl after a flush. Looks a little bit like soap in the bowl when done.

Humans average about 250 grams.
Anything over 500 grams is probably overkill.

It's easier to get repeat sales from toilets that use a 3" flapper.
Repeat sales from pressure assist toilets are hard to get.
I've been selling them for more years, but you can't really argue with the mothers and their kids and tell them to buy another one.
They will let you know if they want more like it.
I guess that's why I don't get many orders for them.

05-29-2007, 04:41 PM
so to answer the original query, YES pressure assist will be noisy. Flush down, or gravity, toilets may be a better choice.

I suggest new thread, called "Sounds. Toilet flush noise." where people post clickable sound file attachments so everyone can compare toilet flush noises.

It might require a lot more bandwidth from the site host.


05-29-2007, 04:45 PM
I have quite a bit of video now from different toilets.
I guess I better edit it up and post it.
They are all done with the same camera with built in mic, Sony VX2000

05-29-2007, 04:50 PM
sound with video stripped out is what I'd listen to. I'd add my own too.


05-29-2007, 05:46 PM
It's nice to see how they work too though.

What I like about using the same camera, is it's consistent audio.
I listened years ago to some put out by some of the companies, and they had the sound levels turned way down low.
What a joke that was.
I've even thought about creating an image of the sound wave for a visual.

TOTO Aquia, with a slight thump. 80 db
TOTO Ultramax, 78 db
Vortens 1.0 pressure assist, 86 db


05-29-2007, 06:43 PM
Received a chart from Zurn with comparison of noise level...
I emailed mansfield and gerber and awaiting noise level info... If you have info... pls do post.

05-31-2007, 06:55 AM
Whether it's pressure-assist (PA) or gravity, noise-levels will always vary from bowl to bowl and manufacturer to manufacturer. Without qualifying the results relative to specific fixtures (i.e. round-front Kohler Wellworth, round-front Mansfield Eco-Flush, etc.) charts like this are more misleading than informative.

I've witnessed "flush sound" wave attenuation tests using Brel & Kjr software in a BK certified acoustic chamber (pictured below) specifically designed for toilet testing where well-known gravity brands have been louder than their pressure-assist counter-parts by anywhere from 4 to 10 dBa.

http://img.photobucket.com/albums/v644/scottitude/plmbg/th_acoustic-chamber.jpg (http://img.photobucket.com/albums/v644/scottitude/plmbg/acoustic-chamber.jpg)

Acoustic engineers define a difference of 5 dBa as being "barely perceptible" to the un-aided human ear so in most cases where the difference is negligible, the results are basically irrelevant.

As "hj" noted, the sheer velocity of the water moving through the bowl pretty much explains the noise-level of pressure-assist toilets.

Another factor is the point in the flush cycle where the peak volume is reached. Peak dBa in gravity toilets typically occurs mid-flush when the toilet breaks trap and the trapway is exposed to atmosphere. PA flushes hit peak dBa almost immediately and the noise level steadily diminishes as the flush cycle completes.

Many people perceive the immediate rush of sound from a PA flush as a louder flush when it may actually have a lower peak dBa rating than their preferred gravity toilet.

I can't seem to find it right now but I have a list of peak dBa levels for a variety home appliances tested in the same chamber. It's a pretty good reference so if I find it, I'll post it.

05-31-2007, 09:37 AM
... perceive the immediate rush of sound from a PA flush as a louder flush when it may actually have a lower peak dBa rating than their preferred gravity toilet. ...yes, all is contextual. I added the underlining. Depending on the immediately preceding sound (type and volume), the next millisecond of sound is received and processed in our brains. It's a process. We compare the sound to its "predecessor"; there is no consistent reference point. A change in sound type and volume makes sounds be perceived as irritating.

DBa is a good unit because it makes clear there is a comparison to whatever the letter 'a' is meant for. DeciBels are comparative units; not counting units.


05-31-2007, 09:52 AM
It is true that such reading can really be misleading. The plumbing setup, the room size, type of flooring , etc can affect the noise reading.

If there will be someone who can make a recording of different toilets that is tested on the same room and same sound/noise reading device.... then that is the true objective test of noise level... You can compare toilets side by side in a controlled setting.

What is needed is just a noise/sound meter (Or a sensitive video camera volume meter) and One bathroom for testing...
If one is in the plumbing business... the results of this test will be really great...

How many customers have 2nd floor bathrooms, babies or elderly at home, apartment and condos where noise isolation is a necessity...

Looking forward to results... Please do post...