Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
Both the Buderus G124X/18 and the Buderus G124X/25 belong to the Bosch Thermotechnology Buderus G124X (Logano G124X II/SP) line of non-condensing boilers. The Buderus G124X/18 is rated 74 MBH input, 53 MBH net rating and 84.3% AFUE, and the Buderus G124X/25 is rated 103 MBH input, 75 MBH net rating and 84.2% AFUE. Buderus G124X/25 lists 29 MBH more input than Buderus G124X/18 (103 MBH against 74 MBH). Buderus G124X/18 carries the higher published AFUE at 84.3%, against 84.2%.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Buderus G124X/18 | Buderus G124X/25 |
|---|---|---|
| Input rate | 74 MBH | 103 MBH |
| Net IBR rating | 53 MBH | 75 MBH |
| DOE heating capacity | 61.4 MBH | 85.5 MBH |
| Efficiency (AFUE) | 84.3 % | 84.2 % |
| Fuel | Natural gas or propane | Natural gas or propane |
| Dry weight | 229 lb | 240 lb |
| Water content | 2.4 US gal | 2.9 US gal |
| Vent connection (B-Vent II) | 5" | 5" |
| Gas connection | 1/2" | 1/2" |
| Boiler supply and return | 1" | 1" |
Published ratings: the Buderus G124X/18 is rated 74 MBH input, 53 MBH net rating and 84.3% AFUE; the Buderus G124X/25 is rated 103 MBH input, 75 MBH net rating and 84.2% AFUE. Buderus G124X/25 lists 29 MBH more input than Buderus G124X/18 (103 MBH against 74 MBH). Buderus G124X/18 carries the higher published AFUE at 84.3%, against 84.2%.
The dry weight differs: the Buderus G124X/18 lists 229 lb, while the Buderus G124X/25 lists 240 lb. The water content differs: the Buderus G124X/18 lists 2.4 US gal, while the Buderus G124X/25 lists 2.9 US gal.
Both records print the same fuel (Natural gas or propane), vent connection (5"), gas connection (1/2") and boiler supply and return (1"), per the cited sources.
Bosch Thermotechnology
The Buderus G124X/18 is a discontinued atmospheric cast-iron gas boiler rated 74 MBH input with 84.3% AFUE, 53 MBH net IBR rating and a 229 lb dry weight.
Bosch Thermotechnology
The Buderus G124X/25 is a discontinued atmospheric cast-iron gas boiler rated 103 MBH input with 84.2% AFUE, 75 MBH net IBR rating and a 240 lb dry weight.
The Buderus G124X/25 lists 103 MBH, against 74 MBH on the Buderus G124X/18, per the cited documentation.
The Buderus G124X/18 carries the higher published AFUE at 84.3%, against 84.2%.
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.