Hi, I want to install a new hot water heater,but I would like to use compression fittings instead of sweating pipe is this possible. Would like to use compression fittings from the copper water lines to the flex hose going into the water heater



Thanks

You can use compression fittings if you don't want to sweat pipe. However, I don't know which flex pipe you plan to use but most will not adapt directly to a compression fitting. You may need to add a coupling to transition from flex to compresssion.

By "flex hose" do you mean the metal braided heater hoses? If so you will need a 3/4" threaded adapter to connect the copperr to the hose connection.
See if you can pickup a Sharkbite adapter. Good luyck, om