Heater displays F15; unit may not detect water pressure correctly.

Safety first: Turn off power and pump before servicing the water pressure switch.

• Locate switch: Find the Nirvana water pressure switch mounted on the water manifold with a small tube or direct tap to the water path.
• Inspect tubing: If equipped with tubing, remove and check for blockages, kinks, or scale. Clean or replace tubing as needed.
• Check switch operation: With pump running and heater off, use a multimeter to verify the switch contacts close under normal system pressure. If not, adjust the set screw slightly (if adjustable) or replace the switch.
• Clean pressure port: Carefully clear any debris from the pressure tap on the manifold using a small drill bit or wire (by hand only).
• Replace if faulty: Install a new OEM Nirvana pressure switch if the old one fails continuity tests.