Want to hook a clothes washer in garage. Next to water heater..
Can you tye into the water heater? And what parts do u need?

Does it ever freeze in your area? Sure you can tie into the water heater. Tap the fed line for cold and the outgoing line for hot. What are you pipe made of?

Sure. Just cut the tubing in hot water line and put in a T. run a pipe from t to washer and put a faucet on the end to accept hot water hose. Do the same for cold water line. If you have copper lines the joints need to be soldered.

Paul

Well, we probably have to ask what kind of plumbing?

The "T" with copper may or may not work, You may require two cuts and a repair coupling to splice into a water line.

You might also want ball valves in addition to the stops for the washer.

Yes, what size line, is there enough volume and pressure to operate at that location. Is there a drain.

What are you doing for a drain?