Check your pressure & temperature valve on the top of the heater. It might have lifted and not seated back properly.

Most common failure is the seals on the flexible lines used to connect to the water heater. Check for water around that connection.

That won’t be covered by a warranty.

Sometimes you can tighten that connection but they have seals in them that compress and often you just have to replace both those flexible copper lines to get new seals to stop the leak. At four years old I would guess you can tighten them providing they were not overtightened originally.

If it is not leaking at a visible place then the tank is bad and that would be covered if you are still in the warranty period. (installation labor will be charged as will costs for bringing up to code, if needed). There is often a label on the tank giving the expiration date.

Good Luck

I would first check all the connections. Next check to see if the T&P valve is leaking (Temp and Pressure) located on the top or side. Check the drain valve to be sure it’s closed tightly. If all this is good out could be your tank and should be covered by your warranty.

It could be either one. Check all the fittings on top of tank. Most warrantys are 5 years