Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The U.S. Boiler Company Independence IN3PVNI and U.S. Boiler Company Independence IN4I are both non-condensing boilers in the U.S. Boiler Company Independence line. Published ratings: U.S. Boiler Company Independence IN3PVNI at 62 MBH input, 52 MBH heating capacity and 83.2% AFUE; U.S. Boiler Company Independence IN4I at 105 MBH input, 87 MBH heating capacity and 82% AFUE. U.S. Boiler Company Independence IN4I lists 43 MBH more input than U.S. Boiler Company Independence IN3PVNI (105 MBH against 62 MBH). U.S. Boiler Company Independence IN3PVNI lists 1.2 percentage points more AFUE than U.S. Boiler Company Independence IN4I (83.2% against 82%). U.S. Boiler Company Independence IN4I lists 65 lb more shipping weight than U.S. Boiler Company Independence IN3PVNI (420 lb against 355 lb).
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | U.S. Boiler Company Independence IN3PVNI | U.S. Boiler Company Independence IN4I |
|---|---|---|
| Input | 62 MBH | 105 MBH |
| DOE heating capacity | 52 MBH | 87 MBH |
| Efficiency (AFUE) | 83.2 % | 82 % |
| Domestic hot water | Heating-only boiler — domestic hot water comes from a separate indirect tank or water heater | Heating-only boiler — domestic hot water comes from a separate indirect tank or water heater |
| Approx. shipping weight | 355 lb | 420 lb |
| Venting | Power vented (draft-inducing fan); 3" AL29-4C stainless steel only | Chimney vented with vent damper and low-profile rear drafthood |
| Fuel | Natural gas (packaged) | Natural gas; LP conversion kits available on IN3–IN9 chimney-vented models |
| AHRI net steam rating | 39 MBH | 65 MBH |
| Steam square feet | 163 sq ft | 271 sq ft |
| Vent length (3" AL29-4C only) | 45 eq ft (3" AL29-4C) | 5×15 in chimney |
| Available configurations | Packaged only | Packaged, Semi-Pak and Knock-Down |
Published ratings: the U.S. Boiler Company Independence IN3PVNI is rated 62 MBH input, 52 MBH heating capacity and 83.2% AFUE; the U.S. Boiler Company Independence IN4I is rated 105 MBH input, 87 MBH heating capacity and 82% AFUE. U.S. Boiler Company Independence IN4I lists 43 MBH more input than U.S. Boiler Company Independence IN3PVNI (105 MBH against 62 MBH). U.S. Boiler Company Independence IN3PVNI lists 1.2 percentage points more AFUE than U.S. Boiler Company Independence IN4I (83.2% against 82%).
U.S. Boiler Company Independence IN4I lists 65 lb more shipping weight than U.S. Boiler Company Independence IN3PVNI (420 lb against 355 lb). The venting differs: the U.S. Boiler Company Independence IN3PVNI lists Power vented (draft-inducing fan); 3" AL29-4C stainless steel only, while the U.S. Boiler Company Independence IN4I lists Chimney vented with vent damper and low-profile rear drafthood. The fuel differs: the U.S. Boiler Company Independence IN3PVNI lists Natural gas (packaged), while the U.S. Boiler Company Independence IN4I lists Natural gas; LP conversion kits available on IN3–IN9 chimney-vented models. The vent length differs: the U.S. Boiler Company Independence IN3PVNI lists 45 eq ft (3" AL29-4C), while the U.S. Boiler Company Independence IN4I lists 5×15 in chimney.
Both models are documented by the official U.S. Boiler Company sources cited on their model records; the shared values above are taken from those documents.
U.S. Boiler Company
The U.S. Boiler Company Independence IN3PVNI is the smallest power-vented model, with the line's highest 83.2% AFUE: 62 MBH input with 52 MBH DOE heating capacity and a 39 MBH AHRI net steam rating at 83.2% AFUE, power vented in 3" AL29-4C stainless.
U.S. Boiler Company
The U.S. Boiler Company Independence IN4I is the second chimney-vented size: 105 MBH input with 87 MBH DOE heating capacity and a 65 MBH AHRI net steam rating at 82% AFUE, chimney vented (5×15 in chimney).
The U.S. Boiler Company Independence IN4I lists 105 MBH, against 62 MBH on the U.S. Boiler Company Independence IN3PVNI, per the cited documentation.
The U.S. Boiler Company Independence IN3PVNI carries the higher published AFUE at 83.2%, against 82%.
It ships at 420 lb against 355 lb for the U.S. Boiler Company Independence IN3PVNI, per the cited sources.
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.