How to Remove Hard Water Stains from Windows

water spots on a window
  • 1-3 hours
  • Intermediate
  • 30
What You'll Need
Oven cleaner
CLR Rust and Lime Remover
RainX windshield protector

Are you wondering how to remove hard water stains from windows? Depending on what caused them, some water stains can be very stubborn and difficult to remove. Try to identify what is the cause of the stains in the first place. This may help you choose the right product to get rid of them. Here some things that you can use and that are known to give good results. You may not have to go through all the steps, but if the first does not get rid of the stains, move on the the next one.

Step 1 - Water and Vinegar

vinegar with lemon and baking soda

The good old water and vinegar trick can work on relatively recent hard water stains. Pour a mix of 1/3 water and 2/3 vinegar in a spray bottle and just spray it all over the window. Let it soak for 1 minute and wipe it off with a dry cloth. You may have to repeat once or twice to completely get it off. If the stains have been there for a while and won’t come off, you may have to try something else.

Step 2 - Oven Cleaner

This is a little trade secret from window cleaning people. If oven cleaner can clean old baked food stains inside an oven, it certainly can clean old hard water stains. You need to spray it on a piece of cloth, not directly on the window and then rinse it with warm water. Make sure to wear rubber gloves when using this product. It is known to remove almost anything. Be careful not to spray it around on painted areas or on plastic.

Step 3 - Use a Scraper

Sometimes even oven cleaner cannot get rid of the hardest stains such as rust. Try using a scraper equipped with a brand new blade to gently scrape off the stain. This is a very time consuming task but it will work at last. Once the stain is gone, do a last cleaning with water and vinegar.

Step 4 - Commercial Cleaners

bottles of cleaners

There are several commercial cleaners on the market that are made to remove hard water stains such as CLR and all the related products. Depending on what caused the windows to be stained, they may work well too.

Step 5 - Protect the Windows

Once you remove the water stains, there are some ways to keep your windows from getting stained again. If the cause is the outside sprinkler system splashing water onto the house, make sure you re-adjust it before cleaning your windows. Otherwise your work will be in vain.

Another good idea is to apply a windshield protector such as RainX on the windows that get a lot of water stains. This actually does well to protect the glass and it makes it a lot easier to clean the stains once they reappear. Maintenance is the key. Washing your windows as soon as you see some stains is a good way to prevent them from getting too hard to clean.