How to use OR statement on multiple columns in Excel?

I have four variables in my excel sheet:

1. Geyser
2. Heater
3. Ac
4. Air cooler

I am creating a new variable in Excel sheet geyser/heater/ac/aircooler which is the combination of all these four variables. If there is a Yes in any one of the above-mentioned columns than the newly created variables should also have "Yes" otherwise it should be blank.

I know how to do that using IF and OR statement for two columns but I don't know how to use it for Four columns.