AquaPlus35 30 Gal. Indirect-Fired Water Heater, Residential, 170,000 BTU

Weil-McLain Aqua-Plus 35 Indirect Water Heater – 30 Gallon Capacity, Stainless Steel Tank

The Weil-McLain Aqua-Plus 35 is a 30-gallon indirect-fired water heater engineered for residential and light commercial hydronic systems. Utilizing a high-capacity stainless steel coil heat exchanger and a 316L stainless steel tank, the Aqua-Plus 35 delivers efficient, high-output domestic hot water production with long-term corrosion resistance. Designed for use with hot water boilers, this unit integrates seamlessly into closed-loop hydronic systems where reliability and performance are required.

Product Highlights

• Tank Construction: 316L stainless steel for high resistance to corrosion, scale, and chemical attack in potable water systems.
• Heat Exchanger: Single-wall 304L stainless steel coil, 1" diameter for increased heat transfer area and reduced pressure drop.
• Insulation: Factory-applied 2" high-density polyurethane foam insulation provides an R-value that minimizes standby heat loss.
• Anode Rod: Magnesium sacrificial anode included to extend service life and suppress electrochemical corrosion.
• Factory Components: Thermostat well and sensor port included; control wiring and sensor routing accessible via top-mounted junction box.
• Adjustable Base: Pre-installed leveling feet allow proper setup on uneven subfloors.
• Relief Valve: ASME-rated temperature and pressure relief valve included, pre-installed to ensure code compliance.

Performance Ratings

• Nominal Capacity: 30 gallons
• First Hour Delivery: 180+ gallons with 180°F boiler water input
• Continuous Flow Rate: Approximately 150–170 GPH @ 100°F rise
• Maximum Heat Input: 170,000 BTU/hr (based on boiler input and flow rate)
• Maximum Working Pressure: 150 psi (tank), 30 psi (coil)

Technical Details

• Tank Material: 316L stainless steel
• Coil Material: 304L stainless steel
• Connections: 1" NPT (coil), 3/4" NPT (domestic)
• Tank Dimensions: Approx. 38" height x 22" diameter
• Weight (Empty): ~105 lbs
• Warranty: Limited lifetime warranty on tank (residential use)

Installation Considerations

Installation of the Aqua-Plus 35 requires boiler integration and should be performed by a licensed plumber or HVAC contractor. The unit must be piped to a closed-loop boiler system with a properly sized circulator and control strategy for optimal performance. All connections should be made in accordance with local plumbing and mechanical codes. Clearance for service and removal of components should be maintained per manufacturer’s specifications.

Professional Use Notes

Contractor Notes: The Aqua-Plus 35 offers a compact footprint and high output ratio, ideal for mid-sized residential hot water loads. Its durable all-stainless design and integrated coil reduce failure points common in glass-lined tanks. Pre-installed relief valve and wiring access points streamline jobsite installation. Tank sensor is compatible with most aquastats or boiler control logic circuits.