If you're thinking about installing a single handle lever faucet in your kitchen, you might be wondering how to to know which is the correct direction for hot and cold. In other words, do you push the handle away from you or do you pull it toward you when you want hot water? You might have even already had it installed and are surprised by the directions of hot and cold, and want to check whether the installation was correct. Here I'm going to answer this question for U.S. kitchen faucets.
The answer is that for a single handle faucet, the supply lines and how they relate to the forward/back lever direction are already built into the faucet (see reference 1). This means that the direction of that lever for hot and cold water depends on the faucet you get. At the time of writing, there is no standard that says that all brands have to have the same direction of lever for hot or cold water. When you purchase the faucet and before installing it, you might not even know yourself which direction hot and cold will be (pushing away vs pulling towards you), although below I cover some ways of how you can tell beforehand.
Here I talk about the lever directions as forward or back, but you could equally think of it as up or down.
Speaking from personal experience, I've had qualified plumbers install a new kitchen faucet on two different occasions, and for the first brand had I got hot water by pushing the lever away from me (and therefore cold by pulling towards me). The second brand of faucet wsa reversed - hot water was done in the direction of pulling the lever toward me (and cold pushing away from me). Needless to say, this change was difficult to get used to without scalding myself! At first I thought the plumber had made a mistake installing, but no. I had him check it and explain it to me while he was there. As shown in reference 1, the direction of hot and cold water is dictated by the faucet itself, and this direction can differ between different brands. The installation instructions make it very clear and easy to know how to set it up. You're likely to install it correctly if you're following the instructions that come with the product, and a qualified plumber is even more likely to install it correctly.
The plumber explained to me some tricks for how to know which direction it might be beforehand, so I'll cover those now.
How to tell beforehand what direction hot and cold water would be for a particular kitchen faucet
On or near the handle (can be very subtle, look extremely closely)
If you're shopping in store, look at the display model very closely, specifically at or near the handle. Many (but not all) brands do provide an indication right there of the direction of hot and cold water. This method also works as a helpful way of checking after the fact if you've already had it installed, so in that case just look at your kitchen's handle or near the handle. Be aware it's often in very tiny writing that you might never see if you're not looking for it. I actually completely missed it on ours at first glance. I'm including a photo here so you can see what I mean:
As you can see from the close-up of the lever base above, the letters H and C indicate the direction of the hot and cold water. However, these markings are difficult to see. If this is not marked on the lever base, check if there are indications elsewhere on the faucet.
In certain colors of a particular model (for example dark bronze) you might not see it as clearly, so if you're in the store display area you might like to look at the display model of the exact same brand in a lighter color.
On the photo on the box
You may also be able to see this same information on the photo on the box. So whether you're shopping online or in person, take a very close look at the photo of the kitchen faucet on the box you're looking at and see if you can find the same type of indicator as I described just above.
On the installation instructions online
Most brands of single handle lever faucets also offer their installation instructions online in case the original information gets misplaced or lost. So if you're considering a particular faucet, it could be well worth looking at the installation instructions online for that brand and model in case there's any indication there of what direction the faucet lever will go for hot and cold water.
There is no U.S. standard requiring all single lever kitchen faucets to have the same direction of push or pull for hot or cold water. This means you could wind up scalding yourself if you were in someone else's house where the hot water was reversed compared to what you expected.
Rest assured that if your new faucet has hot and cold going in the opposite directions to your old faucet, I can attest from personal experience that it really doesn't take long at all to get used to the new direction. It feels a bit weird for the first few days and after that it will become normal and you'll pull or push it the correct way without thinking. So if your faucet goes is the reverse of what you had preferred, it's not as big of a deal as it might first seem.
Of course, if you have any doubts at all about whether your single lever kitchen faucet was installed properly, you should certainly get a qualified plumber in to check it.
1. How to Install a Kitchen Faucet Home Depot