Weil-McLain AquaBalance® Series 2 Combi Gas Boiler - 144 MBH - Stainless Steel Single Tube Heat Exchanger - 95%
The Weil-McLain AquaBalance® Series 2 is a high-efficiency condensing combi boiler designed for both space heating and domestic hot water (DHW). The 144 MBH model (AB-155C Series 2) delivers up to 95% AFUE efficiency, features a stainless steel heat exchanger, and provides continuous hot water on demand while heating the home.
It’s a compact, wall-hung unit ideal for homes that want to maximize efficiency, save space, and eliminate the need for a separate water heater.
🔹 Key Features
High Efficiency
-
95% AFUE – ENERGY STAR® certified.
-
Qualifies for rebates and incentives in many regions.
Dual-Purpose Combi Function
-
Provides both central heating and domestic hot water from a single unit.
-
Eliminates the need for a separate water heater.
Stainless Steel Single Tube Heat Exchanger
-
Corrosion-resistant and durable.
-
Ensures efficient condensing operation and long service life.
Compact, Wall-Hung Design
-
Lightweight and space-saving.
-
Frees up floor space compared to traditional boilers and tanks.
Advanced Controls
-
Digital display with easy-to-use interface.
-
Outdoor reset included for efficiency gains.
-
Compatible with multiple zone panels.
Quiet Operation
-
Designed with sound-dampening for low-noise performance.
Domestic Hot Water Performance
-
On-demand hot water for showers, sinks, and appliances.
-
Flow rates up to 4 GPM (depending on temperature rise).
🔹 Technical Specifications (AB-155C Series 2 – 144 MBH)
| Feature | Value |
|---|---|
| Model | AquaBalance® Series 2 AB-155C |
| Input Capacity (Heating) | 144,000 BTU/hr |
| DOE Heating Capacity | ~134,000 BTU/hr |
| Net I=B=R Rating | ~116,000 BTU/hr |
| AFUE | 95% |
| Heat Exchanger | Stainless steel, single-tube |
| Fuel | Natural Gas or Propane (field convertible) |
| Ignition | Electronic spark ignition |
| Turndown Ratio | 5:1 |
| Venting | PVC, CPVC, or polypropylene; up to 100 ft vent runs |
| Dimensions | ~30″ H × 17″ W × 15″ D |
| Weight | ~110 lbs |
| DHW Output | Up to 4.0 GPM @ 77°F rise |
| Warranty | 12 years (heat exchanger), 2 years (parts), 1 year (labor) – residential |
🔹 Benefits
-
Two-in-one solution – heats both home and domestic water.
-
Ultra-high efficiency (95% AFUE) for fuel savings.
-
Compact, wall-mount design saves space.
-
On-demand hot water – no storage tank required.
-
Stainless steel exchanger ensures durability.
-
Rebate eligible in most areas.
🔹 Considerations
-
Best for small-to-medium homes with moderate hot water demand.
-
If multiple large hot water draws occur simultaneously (e.g., showers + laundry + dishwasher), performance may be limited compared to a separate boiler + indirect tank.
-
Requires condensate drainage due to condensing operation.
✅ Summary
The Weil-McLain AquaBalance® Series 2 Combi Gas Boiler – 144 MBH is a premium high-efficiency solution that delivers both space heating and domestic hot water in a single, compact unit. With a stainless steel single-tube heat exchanger, 95% AFUE rating, and continuous hot water output up to 4 GPM, it’s an excellent choice for space-conscious homeowners who want energy savings, comfort, and convenience.
Choose options