I was quite ensorcelled by the Karbon when we were redoing our kitchen. It didn't fit into the overall aesthetic, so it was just a fancy. I remember thinking that it's more looks than function.

I'll be interested to see if your Karbon is slower in comparison.

Good luck!

I don't have a Karbon so I can't help you with your test, but I am wondering ... would someone else experiencing the same flow issues make it easier to live with the faucet as is? Have you spoken to Kohler about possibly replacing it with a different faucet? I don't agree that it's "no big deal" if it is something that annoys you each and every time you use it. Since a faucet is supposed to deliver water, they should probably be disclosing that this particular faucet has a flow that is "less than others" at the time of sale.

How was the water pressure on your old faucet? Are the shut-off valves fully opened??

How is the water pressure in the rest of the house? I'm willing to bet the problem might be in the plumbing, so maybe remove the faucet and put the supply hoses in a bucket and open the valves to check the flow.

I hate math, but shouldn't it take 60 seconds to fill a 1.8 gallon container when the flow rate is 1.8 GPM? But she says 120 seconds is normal.

Yes, it takes 60 seconds to fill a 1.8 gallon container when the flow rate is 1.8 gal/minute. Are you sure the container is 1.8 gallons? What kind of container holds 1.8 gallons? I am also betting that there is a problem with the plumbing, or debris in the faucet outlet, that should have been flushed out before it was installed.

Is there a screen or aerator in the carbon? I had had all sorts of junk cleaned out of my just installed faucets.

Oh my goodness. I feel so dumb. I guess I'm not good at math either - I didn't put those two together :/

So yes, it should take 60 seconds to fill a 1.8 gallon - not 120 seconds. Duh. Mine took 140 seconds. That's more than twice as slow. The rest of the faucets in the house work fine. It's a new build so I don't have a previous kitchen faucet to compare it to in this house.

Catbuilder- I used a smaller container and tripled the time.

Jellytoast- no, it wouldn't make me feel better if others were okay with the slow flow. I just want to know if it was worth calling Kohler yet again. If the flow I have is the norm for the Karbon, then there's not much they or anyone else can do about it. I did ask about switching the faucet when she suggested that my flow was fine, and she told me that no, they didn't do that.

Janicone- The plumber checked for debris when he installed it. And my husband has taken this thing apart to try and remove any debris that could be stuck in there. At this point, I don't think that anything is blocking the flow.

I will call them again...

What do you mean you tripled the time? What was the actual time, and what was the actual size of the container? The debris could be in a supply valve, or maybe a valve isn't opened all the way or is defective. The Kohler site says the Karbon flow rate is 1.8 gal/min, which is fairly normal. You'll need to remove the faucet and its supply hoses from the equation and test the output from the valves themselves.

1.8gal is 7.2qts. Find something that's 7qts and test again. Surely you have a casserole dish, dutch oven, something. It's a pretty standard size.

Use a gallon milk (or juice) container. Time it in seconds. Divide 60 by the number of seconds it took to fill and that gives you the rate it is filling in gallons per minute. If you don't have a gallon container, just tell us what size container you used and how many seconds it took to fill and we can figure it out for you (if you're having trouble).

I don't have the Karbon installed yet but when I was at Ferguson testing it, the water flow was pretty normal and strong.

There's no way I would have bought the Karbon if the test wasn't decent.

I filled a 76 fl oz container and tripled the time. 1.8 gallons = 230 fl oz

76 x 3 = 230 fl oz

It took 46 secs to fill that container one time. So I multiplied by 3 and got approx. 140 secs. I think I did that right, no?

You have a flow rate of .77 gal/minute, or less than half of what it should be. Have you checked the valves? And were you using all hot, all cold, or mixed?

LOL practigal. I'm in California. They're banking on us getting tired of the time it takes and then settle for less.

@practigal. LOL. I live in California too. Maybe that's the OP's problem. CA requires extra parts that blocks water from flowing. I had to dismantle my entire brand new shower head to remove the blocker. Otherwise, my showers would have been two hours as it drips slowly out.

I've had to buy things from out of state and smuggle them in to avoid the stupid laws in CA.

I tested the Karbon in California and it didn't have unusually low pressure to me. But, I didn't try filling a pot either. I remember seeing a few comments about flow rate being low and Kohler sent another part. My Pirch rep has another part listed on my estimate that accompanies the faucet, a spray head adapter kit, is this what they sent you?

Are you sure that both your shut-offs underneath the sink are opening all the way? We had a similar problem with a defective cold water shut off in our bathroom, even when all the way open, the water flow was pathetic. We switched it out, no more problem.

Somewhat OT: I'm getting a headache just looking at all these calculations people posted above. To think - we had a chance to switch to the beautifully easy metric system and rejected it - it just makes me want to cry. I read that the only countries that still rely on the imperial system other than the US are Myanmar and Liberia !?! Sheesh, now I'm really sobbing.

Saida - I have had my KK for ~4 years now and still love it. It did come with a low flow aerator which we switched out for a high flow one. (Maybe that's what you did already?)

We do have to perform maintenance on it fairly regularly (1 - 2 times a year), so I documented the process, linked here, last year. It's a minor inconvenience and I would buy the faucet again.

I think our flow is a little slow right now, so will post again, once DH has cleaned it this weekend. We are on well water. It took 57.92 seconds to fill a gallon.

I also searched old threads and found this advice, from texaspenny:

"When my Karbon was installed the water flow was 'limp'. I was so disappointed. My plumber took an hour and took the whole thing apart, took each section and blew into it. Finally I called Kohler while he was there and the last thing we hadn't checked was the last section with the spray button. They said to push the button in, take off the cover and check those parts. He blew into that and a tiny tiny piece of red plastic shot out. After that, everything was fine and the pressure was strong.

He also had taken the faucet off the base, put a cup over the hole and turned it on to make sure the water was coming out at pressure. That way we knew the water was coming at pressure but there was something in the faucet itself that was blocking it. "

Here's my little honey:

Saida is in Canada (Quebec, I think) which makes it worse, Pippa, as we DO use the metric system but being so close to the US lots of the service reps and pamphlets we get are American and you have to try to convert things in your head. I'm literally right on the US border in Ontario and virtually no one here uses Celcius for temperature except me, that I know of. Saida, I'm sorry this is one more thing that is messed up in your kitchen. You must be at your wits end by now. Hugs!

Oldbat2be - I love your faucet and I also love your countertop. Would you mind sharing what countertop you have. Thanks.

caligirl8i8 - thanks! Countertop is Cambria Torquay.

@beachem, lol at smuggling things in to CA! Gotta love the nonsense regulations here huh?

Why are they nonsense - Isn't California in an epic drought?

freeoscar - the sink and shower flow restrictors in CA are nonsense because something like 80% of the water is used by agriculture. When you take the 20% left, that is split between all other uses - so private homes, businesses, and gov't. Of that, most probably goes down the toilet or is used to make grass green. So, basically, the elephants in the room are ag and golf courses and lawn watering, but the homeowner must suffer a restricted flow to sinks and showers - which in reality just means one must shower longer or keep the faucet going longer.

@freeoscar, the majority of our water use is by almond growers. It's been a major complaint for decades. Our home water use is being cut by 20% every year and we get fined if we use the same amount of water as the year before but the ag industry doesn't suffer at all and gets subsidies as well.

Well there was that house in Bel Air that was using 1300 gallons per hour! Water rights in CA are contested and vary considerably depending on where you are. You can really see the difference if you stay on the 5 or take the 99 through the central valley.

My faucet was purchased when it was at 2.2 gpm and the pressure is soooo low. The new 1.8 has to be worse, begging the question-why buy a performance faucet? Also some of the faucets are designed with an integral water restrictor and cannot be removed.

Almond farmers and of course Nestle (taking public water and selling for profit).

Our water companies and county have issued mandatory water restrictions. You know what they did when people complied and are now using less water? Increased rates because of lost revenue from less usage. Go figure.

@practigal that's where smuggling comes in handy. Depend on the state you can buy faucets without the integral water restrictor.

Where would one buy a smuggled Karbon? If I order off Wayfair should I have it shipped elsewhere?

This discussion it taking a turn towards "dark web" territory. ha

Pssst. I may know a guy who knows a guy who can get you a non-flow-restricted Karbon to sell. Email me at darkwater@silkroad.com. Be forewarned, they only accept payment in Bitcoin.

I did not buy a Kohler but when I got my new faucet, the flow was very slow. My plumber had to blow into it, too, and some random piece came out of it. Then it worked fine. Weird.

Here's a thread discussing this issue:

http://ths.gardenweb.com/discussions/2687907/feedback-on-kohler-karbon-faucet

From what my plumber tells me, cheaper faucets from the big boxes in CA has the restrictor built in and you can't remove. More expensive faucets that you buy from specialty or distributor can be disassemble so you can take the restrictor out.

It seems like the Karbon can be adjusted with the higher flow part.

PS I mostly smuggle paint, oil and mineral spirit.

Were you able to try any of the suggestions yet, Saida?

Freeoscar, it's nonsense in California because it still takes just as much water to do a task, it just takes longer to do the task if the water is coming out slower. I need water to rinse my hair ... if it comes out of the tap slower, I just need to stand there longer to get the soap out! Yes, we are in the midst of an epic drought, but forced conservation that doesn't actually result in actual conservation seems stupid. There is not a restrictive valve on my outdoor hose, yet the water will trickle out of the restricted faucets indoors! In my area, they keep us in line with penalties for over using beyond your pre-determined household limit, but if you can afford the penalties, you can use the water.