Williamson-Thermoflo GWA-166
The Williamson-Thermoflo GWA-166 is a 84% AFUE cast iron boiler with a 166,000 BTU input BTU output, part of the Williamson-Thermoflo GWA Series 3 line. GasBoilers.ca installs, repairs, and maintains the GWA-166 across Greater Vancouver — Red Seal–certified, TSBC-licensed, same-day repair available. Call 604-359-1081.
Williamson-Thermoflo GWA-166 overview
The GWA Series 3 is an atmospheric cast-iron gas hot-water boiler rated at 84% AFUE with a built-in air separator. Its rugged sectional design and chimney venting make it a dependable, budget-friendly choice for traditional hydronic systems.
84% AFUE
Efficiency
166,000 BTU input
BTU Output
Up to 12 years
Warranty
GWA-166 specifications
| Model | Williamson-Thermoflo GWA-166 |
| Series | GWA Series 3 |
| Type | cast iron |
| BTU Output | 166,000 BTU input |
| Efficiency | 84% AFUE |
| Warranty | Up to 12 years |
| Origin | United States |
| Best for | Mid-size homes |
GWA Series 3 features
Williamson-Thermoflo GWA-166 services we provide
All work by licensed BC gas-fitters — TSBC-certified.
GWA-166 Installation
Permit, sizing, venting, gas, commissioning.
From $5,500
GWA-166 Repair
Error code diagnosis, parts, full repair.
From $189
GWA-166 Maintenance
Annual tune-up — required for warranty.
From $169
GWA-166 Replacement
Upgrade an older unit. Rebate-eligible.
From $5,500
Emergency Service
Same-day no-heat, leak, CO, gas-smell response.
Call 604-359-1081
Warranty Service
Authorized warranty repairs for Williamson-Thermoflo.
Warranty-covered
Williamson-Thermoflo GWA-166 — frequently asked questions
How much does Williamson-Thermoflo GWA-166 installation cost in Vancouver?
Williamson-Thermoflo GWA-166 installation starts from $5,500 in Greater Vancouver, including permit, code-compliant venting and gas piping, removal of the old unit, and full commissioning. Final pricing depends on your existing system and a heat-loss calculation. Call 604-359-1081 for a free quote.
What size is the Williamson-Thermoflo GWA-166?
The Williamson-Thermoflo GWA-166 has a heating output of 166,000 BTU input BTU, with 84% AFUE efficiency. It is best suited to mid-size homes.
Do you repair the Williamson-Thermoflo GWA-166?
Yes. We diagnose and repair the Williamson-Thermoflo GWA-166 — error codes, ignition faults, no-heat, leaks, low pressure, and sensor issues — from $189. Our technicians are factory-trained on Williamson-Thermoflo GWA Series 3 units and carry common parts on the truck.
How often should the Williamson-Thermoflo GWA-166 be serviced?
Williamson-Thermoflo recommends annual maintenance to keep the GWA-166 efficient, safe, and within warranty (up to up to 12 years). Our maintenance service starts from $169.
Williamson-Thermoflo GWA-166 service across Greater Vancouver
We service the GWA-166 in every major Greater Vancouver city.
Other Williamson-Thermoflo GWA Series 3 Models
Book Williamson-Thermoflo GWA-166 service today
Same-day repair available · Free installation quotes · Licensed gas-fitters