Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
Boilers.ca is a brand of ROMA Heating & Cooling · Licensed gas contractor LGA0202903
Comparison
Verdict in brief
The discontinued GA124/17 and GA124/30 are sealed-combustion cast-iron boilers with 3" combustion-air and 3" flue connections and 1" supply/return. The /17 produces 59 MBtu/hr output at 229 lb empty weight and 2.4 US gal; the /30 produces 104 MBtu/hr at 337 lb and 3.4 US gal.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Buderus GA124/17 | Buderus GA124/30 |
|---|---|---|
| Boiler output | 59 MBtu/hr | 104 MBtu/hr |
| Empty weight | 229 lb | 337 lb |
| Water volume | 2.4 US gal | 3.4 US gal |
| Flue gas connection | 3" | 3" |
| Combustion air connection | 3" | 3" |
Both sizes share the GA124's sealed-combustion architecture: combustion air is drawn from outdoors through a 3" connection and flue gases leave through a 3" connection, with 1" boiler supply and return and a 1/2" gas connection, per the installation and maintenance manual.
Output and physical rows scale across the three sizes: 59 MBtu/hr / 229 lb / 2.4 gal on the /17, 79 MBtu/hr / 240 lb / 2.9 gal on the /23, and 104 MBtu/hr / 337 lb / 3.4 gal on the /30.
The GA124 is out of Bosch's current Canadian catalog; its installation/maintenance and operating manuals plus propane conversion and altitude documents remain in the Canadian technical-documentation library.
Bosch Thermotechnology
The Buderus GA124/17 is a discontinued sealed-combustion cast-iron gas boiler rated 59 MBtu/hr output with a 229 lb empty weight and 2.4 US gal water volume.
Bosch Thermotechnology
The Buderus GA124/30 is a discontinued sealed-combustion cast-iron gas boiler rated 104 MBtu/hr output with a 337 lb empty weight and 3.4 US gal water volume.
The boiler draws combustion air directly from outdoors and vents flue gases through dedicated 3" connections rather than using indoor air or a draft hood, as documented in the installation and maintenance manual.
The /17 at 59 MBtu/hr output is the smallest; the /23 and /30 step up to 79 and 104 MBtu/hr. Sizing should follow a heat-loss calculation.
A consultation includes a heat-loss review so the size is right the first time.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.