The natural gas heater is located out by the pool equipment. On the far side of the heater, there is a flap that opens and you can tap the mode button once. Once you tap the mode button, go inside the laundry room and notice the remote on the wall behind the door. You can turn on the pool heat, spa heat, pool light and spa light, as well as the air blower for the spa. Remember, if you leave this on too long the gas bill will be affected, and the tenants are responsible for this bill. Once the pool\spa has reached the desired temperature, tap the mode button again to turn off for each use. The spa reached max temperature of 104 in approximately twenty minutes. If you would like, I can text you a video.