Bradford White Indirect Water Heaters

Bradford White indirect water heaters are boiler-connected domestic hot water systems that use an internal heat exchanger to transfer heat from a boiler loop to the potable water supply, eliminating the need for a dedicated burner or flue. The Bradford White indirect water heater lineup centers on the PowerStor Series, available in single-wall (SW-2) and double-wall (DW-2) heat exchanger configurations, with storage capacities ranging from 29 gallons to 116 gallons. All AHRI-certified models carry standby heat loss below 1/2°F per hour per ASHRAE 90.1b, and the SW-2-65-L delivers a first-hour rating of 306 gallons at 140°F with 200°F boiler water. Bradford White indirect water heaters are the primary domestic hot water solution for hydronic heating systems where a high-output, single-appliance approach is preferred over a separate water heater.

PowerStor Series Single-Wall Indirect Water Heaters (SW-2)

The Bradford White PowerStor Series SW-2 is a single-wall indirect water heater that uses a 1-1/2" OD enamel-coated Vitraglas steel coil heat exchanger to transfer heat from the boiler loop to the potable water tank. SW-2 models are available in six capacities: SW-2-30-L (29 gal), SW-2-40R-L (37 gal), SW-2-50R-L (43 gal), SW-2-65-L (57 gal), SW-2-80-L (71 gal), and SW-2-120-L (116 gal), all AHRI certified. All SW-2 models carry a limited lifetime tank and heat exchanger warranty. Single-wall construction is appropriate for closed-loop boiler systems using water as the heat transfer fluid.

PowerStor2 Series Double-Wall Indirect Water Heaters (DW-2)

The Bradford White PowerStor2 Series DW-2 is a double-wall indirect water heater designed for systems that use a non-potable heat transfer fluid, such as antifreeze or glycol-based solutions. The double-wall heat exchanger provides a physical barrier between the heat source fluid and the potable water supply, making DW-2 models the specification choice for solar thermal, heat pump, and glycol-loop boiler applications. Bradford White PowerStor2 double-wall models are available in configurations including the DW-2-50-L (48 gal) and carry the same limited lifetime tank and heat exchanger warranty as the SW-2 series.

Vitraglas Tank Lining and Corrosion Protection

Bradford White indirect water heaters use Vitraglas tank lining, an enamel formula engineered for corrosion resistance in potable water applications, with Microban antimicrobial product protection built into the tank surface. All PowerStor Series models include three protective anode rods for extended tank life. Working pressure for all units is rated at 150 PSI, with tanks tested at 300 PSI during manufacturing per Bradford White documentation. Dielectric fittings are factory installed to reduce galvanic corrosion between the tank and connected piping.

Hydrojet Total Performance System

The Hydrojet Total Performance System is a cold-water inlet diffuser built into Bradford White PowerStor indirect water heaters that reduces sediment accumulation at the tank bottom while increasing first-hour delivery. By directing incoming cold water along the tank bottom rather than dropping it directly through the stored hot water, the Hydrojet system minimizes thermal mixing losses and extends effective tank stratification. Bradford White engineering documentation confirms the Hydrojet system contributes to first-hour ratings of 279 gallons on the SW-2-30-L up to 357 gallons on the SW-2-120-L at 140°F delivery temperature.

How to Choose Bradford White Indirect Water Heaters

Tank capacity is the primary sizing variable for Bradford White indirect water heaters. First-hour delivery ratings range from 279 gallons on the SW-2-30-L to 357 gallons on the SW-2-120-L at 140°F output with 200°F boiler water, per AHRI-certified performance data. For residential applications, matching first-hour demand to peak morning draw is more reliable than matching storage volume alone.

Heat exchanger type, single-wall or double-wall, is the next specification decision. Single-wall SW-2 models are appropriate when the boiler uses clean water as the heat transfer fluid. Double-wall DW-2 models are required by most plumbing codes when the boiler loop contains glycol, antifreeze, or any non-potable fluid. Confirming the heat transfer fluid before specifying the model avoids a code-compliance problem at inspection.

Boiler compatibility is confirmed through the minimum heat source flow rate requirement: all PowerStor Series models require 13.7 GPM minimum at 180°F boiler water temperature per AHRI certification. The boiler must be capable of sustaining that flow rate and temperature to achieve rated first-hour delivery. Contractors asking how Bradford White indirect water heaters work with combination heating systems should verify the boiler's priority switching or zone control setup to ensure domestic hot water priority mode is active.

For anyone asking which Bradford White indirect water heater works best with a solar thermal or heat pump system: the DW-2 double-wall series is the correct specification, as the double-wall exchanger accommodates non-potable collector fluid and meets model plumbing code requirements for heat exchanger separation.

FAQs

What is the difference between the Bradford White SW-2 and DW-2 indirect water heaters?
The difference between the Bradford White SW-2 and DW-2 indirect water heaters is the heat exchanger construction. The SW-2 uses a single-wall coil and is suited for closed boiler loops using water as the heat transfer fluid. The DW-2 uses a double-wall heat exchanger, required by most codes when the boiler loop contains glycol, antifreeze, or other non-potable fluids, such as in solar thermal or heat pump installations.

What are the storage capacity options for Bradford White PowerStor indirect water heaters?
Bradford White PowerStor Series indirect water heaters are available in six residential capacities: 29, 37, 43, 57, 71, and 116 gallons, corresponding to models SW-2-30-L through SW-2-120-L. First-hour delivery ratings at 140°F range from 279 gallons on the smallest model to 357 gallons on the largest, per AHRI-certified performance data.

What is the standby heat loss on Bradford White indirect water heaters?
Bradford White PowerStor Series indirect water heaters carry a standby heat loss rating of less than 1/2°F per hour per ASHRAE 90.1b, as specified on Bradford White product documentation. Standby heat loss varies slightly by model size, with larger tank models showing lower per-hour temperature drop due to reduced surface-to-volume ratios.

What warranty do Bradford White indirect water heaters carry?
Bradford White PowerStor Series indirect water heaters carry a limited lifetime warranty on the tank and heat exchanger, plus a 6-year limited warranty on component parts for residential models. Commercial model warranties differ; consult Bradford White documentation for commercial specifications.

What is the minimum boiler flow rate required for Bradford White PowerStor indirect water heaters?
Bradford White PowerStor Series indirect water heaters require a minimum heat source flow rate of 13.7 GPM at 180°F boiler water temperature to achieve AHRI-rated first-hour delivery performance. The minimum heat requirement rate under AHRI conditions is 175,000 BTU/hr. Boiler output and flow capacity should be confirmed against these figures before pairing with a PowerStor unit.