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 Rinnai IP150S and Rinnai IP175S are both condensing boilers in the Rinnai i-Series+ Solo line. The Rinnai IP150S is rated 15–150 MBH input and 96% AFUE, and the Rinnai IP175S is rated 15–175 MBH input and 96% AFUE. Rinnai IP175S lists 25 MBH more input than Rinnai IP150S (175 MBH against 150 MBH). Both list the same published AFUE of 96%. Rinnai IP175S lists 47.6 lb more shipping weight than Rinnai IP150S (112.4 lb against 64.8 lb).
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Rinnai IP150S | Rinnai IP175S |
|---|---|---|
| Heating input, minimum | 15 MBH | 15 MBH |
| Heating input, maximum | 150 MBH | 175 MBH |
| Efficiency (AFUE) | 96 % | 96 % |
| Domestic hot water | Heating-only boiler; domestic hot water via an indirect tank | Heating-only boiler; domestic hot water via an indirect tank |
| Water content (CH) | 0.88 gal | 2.4 gal |
| Weight | 64.8 lb | 112.4 lb |
| Width | 18.5 in (470 mm) | 19.45 in (494 mm) |
| Depth | 11.5 in (291 mm) | 15.48 in (393.3 mm) |
| Venting | 2" nominal PVC/polypropylene or 3" x 5" concentric | 2" nominal PVC/polypropylene or 3" x 5" concentric |
| Max. equivalent vent length, 2" | 75 ft | 75 ft |
| Max. equivalent vent length, 3" | 160 ft | 160 ft |
| Heating water connections | 1" NPT | 1" NPT |
| Gas connection | 3/4" NPT | 3/4" NPT |
| Fuel | Natural gas or propane | Natural gas or propane |
| CH water pressure | 13 – 45 psi | 13 – 45 psi |
Published ratings: the Rinnai IP150S is rated 15–150 MBH input and 96% AFUE; the Rinnai IP175S is rated 15–175 MBH input and 96% AFUE. Rinnai IP175S lists 25 MBH more input than Rinnai IP150S (175 MBH against 150 MBH). Both list the same published AFUE of 96%.
Rinnai IP175S lists 47.6 lb more shipping weight than Rinnai IP150S (112.4 lb against 64.8 lb). The boiler water content differs: the Rinnai IP150S lists 0.88 gal, while the Rinnai IP175S lists 2.4 gal. The width differs: the Rinnai IP150S lists 18.5 in (470 mm), while the Rinnai IP175S lists 19.45 in (494 mm). The depth differs: the Rinnai IP150S lists 11.5 in (291 mm), while the Rinnai IP175S lists 15.48 in (393.3 mm).
Both records print the same input (15 MBH), AFUE (96%), domestic-hot-water arrangement (Heating-only boiler; domestic hot water via an indirect tank) and venting (2" nominal PVC/polypropylene or 3" x 5" concentric), per the cited sources.
Rinnai
The Rinnai IP150S is the largest fully documented I-Series+ solo: a heating-only condensing boiler firing 15 to 150 MBH of input at 64.8 lb per the manual, controlling an indirect tank for domestic hot water.
Rinnai
The Rinnai IP175S is the 175k heating-only I-Series+ solo on the large chassis, marketed on rinnai.ca as available since September 2024 and documented on Boilers.ca from the EN I&O manual (doc 800000216) at 112.4 lb. It is named in Health Canada recall RA-77507.
The Rinnai IP175S lists 175 MBH, against 150 MBH on the Rinnai IP150S, per the cited documentation.
Both list the same AFUE of 96%.
It ships at 112.4 lb against 64.8 lb for the Rinnai IP150S, 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.