**Model Family:** Pentair MasterTemp 400

**BTU Input:** 400,000 BTU/hr

**Fuel Types:**

- Natural Gas – common model: 460736

- Propane (LP) – common model: 460737

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### Performance & Application

- **Use:** In-ground pools and spas (residential/light commercial)

- **Heating Capacity:** 400,000 BTU/hr (fast heat-up for large pools or attached spas)

- **Thermal Efficiency:** Up to ~84% (low-NOx versions meet strict air quality standards in many regions)

- **Max Water Flow:** Typically up to ~120 GPM (internal bypass helps manage higher system flows)

- **Minimum Flow to Fire:** ~20–25 GPM (varies slightly by install and plumbing)

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### Physical Specs

- **Approx. Dimensions:**

- Height: ~28–29 in

- Width: ~21 in

- Depth: ~30 in

- **Approx. Weight:** 125–140 lbs (varies by