Williamson-Thermoflo FS-120 (Combi)
The Williamson-Thermoflo FS-120 (Combi) is a 95% AFUE combi boiler with a 120,000 BTU input BTU output and Combi DHW model of domestic hot water, part of the Williamson-Thermoflo FreeStyle Series 2 line. GasBoilers.ca installs, repairs, and maintains the FS-120 (Combi) across Greater Vancouver — Red Seal–certified, TSBC-licensed, same-day repair available. Call 604-359-1081.
Williamson-Thermoflo FS-120 (Combi) overview
The FreeStyle Series 2 is a wall-mounted gas-fired condensing boiler with a stainless-steel heat exchanger and modulating combustion rated at 95% AFUE. It is offered in heat-only and combination (combi) versions across three input sizes, with flexible PVC, CPVC, PP or stainless venting.
95% AFUE
Efficiency
120,000 BTU input
BTU Output
Combi DHW model
DHW Flow
FS-120 (Combi) specifications
| Model | Williamson-Thermoflo FS-120 (Combi) |
| Series | FreeStyle Series 2 |
| Type | combi |
| BTU Output | 120,000 BTU input |
| DHW Flow | Combi DHW model |
| Efficiency | 95% AFUE |
| Warranty | Up to 12 years |
| Origin | United States |
| Best for | Mid-size homes needing heat plus hot water |
FreeStyle Series 2 features
Williamson-Thermoflo FS-120 (Combi) services we provide
All work by licensed BC gas-fitters — TSBC-certified.
FS-120 (Combi) Installation
Permit, sizing, venting, gas, commissioning.
From $6,500
FS-120 (Combi) Repair
Error code diagnosis, parts, full repair.
From $189
FS-120 (Combi) Maintenance
Annual tune-up — required for warranty.
From $169
FS-120 (Combi) Replacement
Upgrade an older unit. Rebate-eligible.
From $6,500
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 FS-120 (Combi) — frequently asked questions
How much does Williamson-Thermoflo FS-120 (Combi) installation cost in Vancouver?
Williamson-Thermoflo FS-120 (Combi) installation starts from $6,500 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 FS-120 (Combi)?
The Williamson-Thermoflo FS-120 (Combi) has a heating output of 120,000 BTU input BTU and delivers Combi DHW model of domestic hot water, with 95% AFUE efficiency. It is best suited to mid-size homes needing heat plus hot water.
Do you repair the Williamson-Thermoflo FS-120 (Combi)?
Yes. We diagnose and repair the Williamson-Thermoflo FS-120 (Combi) — error codes, ignition faults, no-heat, leaks, low pressure, and sensor issues — from $189. Our technicians are factory-trained on Williamson-Thermoflo FreeStyle Series 2 units and carry common parts on the truck.
How often should the Williamson-Thermoflo FS-120 (Combi) be serviced?
Williamson-Thermoflo recommends annual maintenance to keep the FS-120 (Combi) efficient, safe, and within warranty (up to up to 12 years). Our maintenance service starts from $169.
Williamson-Thermoflo FS-120 (Combi) service across Greater Vancouver
We service the FS-120 (Combi) in every major Greater Vancouver city.
Other Williamson-Thermoflo FreeStyle Series 2 Models
Book Williamson-Thermoflo FS-120 (Combi) service today
Same-day repair available · Free installation quotes · Licensed gas-fitters