Raypak Digital Low NOx ASME Natural Gas Pool Heater, 332.5K BTU, Copper Heat Exchanger, Bronze Headers, B-R337A-EN-C #26, 017707

The Raypak B-R337A-EN-C #26, part number 017707, is the 337A size of Raypak's Digital Low NOx ASME pool and spa heater: 332,500 BTU/hr input on natural gas, 2 inch bronze headers and a copper fin tube heat exchanger, rated for installations up to 5,000 ft.

Low NOx

On the Low NOx ASME models a gas valve and blower hold the air fuel mixture, so the heater burns clean. Raypak says these models meet the additional safety standards and regulations required for Texas, California and Utah, and offers a flow switch option that makes them Texas Boiler Code compliant.

The ASME build

The B at the front of the model number is Raypak's code for bronze ASME headers. The heater ships with a 125 psi pressure relief valve, carries the ANSI Z21.56 design certification, and can be installed indoors or out, directly on a combustible surface. Whether a pool needs an ASME heater is for the local code and the inspector to say.

Before you order

Raypak lists the Low NOx ASME heaters for natural gas only, and its manual says the rated input is suitable up to 5,000 ft. This one has a copper exchanger; Raypak sells the cupronickel version under its own part number. At the rated 82 percent thermal efficiency it puts about 272,650 BTU/hr into the water. Power is 120 or 240 VAC, single phase, at 6 A or 3 A.