The old faucet on your kitchen sink might need replacing, and this seems like it could be a simple enough job for you to handle on your own. However, installing a new faucet on a kitchen sink can be much harder than it looks. Here is a look at the three top things DIYers tend to do wrong when they don't call on a plumbing service for help.

1. Not Removing Old Putty and Adhesive Before Installing the New Faucet 

When you pull off the old faucet, you will likely find a layer of gunk beneath it. This sticky residue is plumber's putty or some other adhesive that was used to create a tight seal when the faucet was put in place. It is best to use a plastic scraper and maybe some chemical cleaner to remove all the residue. If you don't, you will have issues getting the new faucet to seat and seal properly when you put it in place with the new adhesive. Keep in mind that it can be really easy to leave deep scratches in some sinks while trying to remove the residue, which is why most people trust a plumbing professional instead. 

2. Overtightening the Mounting Hardware During Installation

Once the faucet is seated in place, you will have a few fasteners that you will use to tighten the faucet securely in place. Typically, there will be two bolts on the underside of a sink faucet, for example, and screws that go in the center of each faucet handle before you put on the knobs. If you overtighten any of these fasteners, it can cause a lot of problems with how the faucet functions and potentially cause damage to the sink itself. 

3. Failing to Securely Connect the Water Feed Lines to the Faucet 

The water feed lines that lead to the faucet give you hot and cold water when you turn each faucet handle. The lines usually have pre-threaded brass couplers that you use to attach the hoses to each faucet handle. If you don't get these couplers secure or put them on at an awkward angle, you will have ongoing issues with the hoses leaking water even when the sink is not in use. Unfortunately, the leaks here can be slow and hard to catch, so they can lead to water damage under the sink. When a professional plumbing service installs a faucet for you, they use special tape to make sure there is a tight seal at these hoses.