Pentair MasterTemp 400 Heater Replacement in Davenport

The Problem

Homeowner called us in January because their pool heater would not ignite. The heater was a 12-year-old Raypak 336A gas heater. It had been repaired twice in the past two years—once for the ignition module, once for the pressure switch.

During diagnosis, we found the heat exchanger had a pinhole leak with visible green corrosion and water dripping inside the cabinet. A heat exchanger replacement on a 12-year-old unit is not cost-effective—the exchanger alone costs nearly as much as a new heater, and the rest of the unit was showing its age.

Our Recommendation

We recommended a full replacement with a Pentair MasterTemp 400. The MasterTemp heats faster than the old Raypak, has a longer expected lifespan, and has better energy efficiency. We discussed heat pump options as well, but the homeowner preferred gas for fast heating since they use the pool primarily on weekends.

The Installation

• Disconnected and removed the old Raypak 336A
• Inspected the gas line for leaks and proper pressure (passed)
• Installed new Pentair MasterTemp 400 on the existing pad
• Connected gas, plumbing, and electrical
• Programmed automation system to recognize the new heater
• Tested ignition, heating cycle, and safety shutoffs
• Pool reached 85°F in under 2 hours from a 68°F starting temperature

Results

Key Takeaway

When a heater is 10+ years old with a cracked heat exchanger, replacement almost always makes more sense than repair. The cost difference between exchanger replacement and a new unit is small, but the new unit gives you a full warranty, better efficiency, and years of reliable service. We always present both options with pricing so you can make the best decision.