This is a gas hotwater heater with an electric ignition. It states it is not to be lit manually.
It is 2 years old and the ignitor won't start. I don't see a spark when I push it down 4-5 times as directed. There is gas supply to the rest of the house. There is water in the tank in the

I think the proper term is spark ignitor. First tell us if you have the gas valve turned to pilot and are you pushing in on the gas valve knob.

In addition to Ballengerb1's suggestion: Do visual inspection of the exposed low voltage wiring at the thermostatic valve. Make sure all wires are attached making positive contact. Also, there is a ground wire attached to the body of the heater. Make sure that wire is attached as well.

Back to you. Milo

PS: Let me guess the brand: GE heater purchased from Home Depot ?