Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The MGB-120K and MGB-150K are adjacent sizes in the current MGB-K cast-iron water line — both non-condensing atmospheric boilers at 84% AFUE with 1¼" NPT water connections and a Hydrolevel control with built-in LWCO. The MGB-150K fires 149 MBH against 120 MBH, printing 125 MBH of heating capacity (101) and a 109 MBH net AHRI water rating (88); both use a 6" flue connection and the cabinet changes from 16¼ × 32⅛ × 27¼ in to 19 × 32⅛ × 27¼ in, with 5 burners against 4 and a shipping weight of 335 lb against 295 lb.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Utica MGB-120K | Utica MGB-150K |
|---|---|---|
| Input | 120 MBH | 149 MBH |
| Heating capacity | 101 MBH | 125 MBH |
| Net AHRI water rating | 88 MBH | 109 MBH |
| AFUE | 84 % | 84 % |
| Boiler water content | 2.8 gal | 3.2 gal |
| Flue connection | 6" | 6" |
| Burners | 4 | 5 |
| Dimensions (W x H x D) | 16¼ × 32⅛ × 27¼ | 19 × 32⅛ × 27¼ |
| Shipping weight | 295 lb | 335 lb |
Both models are MGB-K cast-iron water boilers at 84% AFUE — a non-condensing, atmospheric chimney-vented design with an integral low-profile draft hood, motorized vent damper, dry-leg cast-iron heat exchanger and a Hydrolevel control with built-in low water cut-off. Neither modulates: input is fixed.
The brochure table prints 120 MBH input with 101 MBH heating capacity and a 88 MBH net AHRI water rating on the MGB-120K, against 149 MBH, 125 MBH and 109 MBH on the MGB-150K. Boiler water content rises from 2.8 to 3.2 gal and burner count from 4 to 5.
Installation details move with size: both use a 6" flue connection, both take ½" NPT gas, and the cabinet changes from 16¼ × 32⅛ × 27¼ in to 19 × 32⅛ × 27¼ in; shipping weight rises from 295 to 335 lb. A licensed heat-loss calculation should decide between the two — extra capacity beyond the design load only shortens run times in a fixed-input boiler.
Utica Boilers
The Utica MGB-120K is a size in the current MGB-K cast-iron water line: 120 MBH fixed input, 101 MBH heating capacity, a 88 MBH net AHRI water rating and 84% AFUE, with atmospheric chimney venting, a 6" flue and 4 burners. Its card carries the official 'Current' and 'Available in Canada' tags.
Utica Boilers
The Utica MGB-150K is a size in the current MGB-K cast-iron water line: 149 MBH fixed input, 125 MBH heating capacity, a 109 MBH net AHRI water rating and 84% AFUE, with atmospheric chimney venting, a 6" flue and 5 burners. Its card carries the official 'Current' and 'Available in Canada' tags.
149 MBH input against 120 MBH, 125 MBH heating capacity against 101 MBH, and a 109 MBH net AHRI water rating against 88 MBH, per the official MGB-K brochure table.
No — every MGB-K is a non-condensing cast-iron boiler at 84% AFUE with atmospheric chimney venting, an integral draft hood and a motorized vent damper.
Size from a licensed heat-loss calculation: the MGB-120K suits loads that fit its 101 MBH heating capacity, while the MGB-150K covers loads approaching 125 MBH. Neither modulates, so oversizing shows up as shorter run cycles.
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.