Rinnai IP120S
The Rinnai IP120S steps the heating-only solo line up to 120 MBH of input (15-120 MBH) on the 10.9 sq ft heat exchanger at 64.8 lb per the manual, with hot water handled by an indirect tank.
Key figures
- Max input
- 120 MBH
- Max CSA output
- —
- AFUE
- 96 %
- Min input
- 15 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Rinnai IP120S in practice
The IP120S is the first of the two larger small-chassis solos: 15,000 to 120,000 BTU/h of central-heating input, a 10.9 sq ft heat exchanger and 0.88 gal of CH water per the I&O manual. Its weight per the manual is 64.8 lb (29.4 kg) — the product page's 112.4 lb figure matches the IP175S/IP199S manual weight and is documented as an apparent page copy error.
Heating-only by design, the IP120S carries no DHW connections; the solo manual documents indirect-tank control (recovery priority by default, parameter 33 for simultaneous operation). Venting is 75 equivalent feet in 2" or 160 in 3" twin pipe.
The family efficiency claim is up to 96% AFUE in Rinnai's Canadian marketing; the manual spec table prints no per-model AFUE figure. Codes display as plain numbers with solo-only indirect-tank rows in the solo manual.
Best suited to
- Homes with an indirect tank and a heat-loss calculation near 120 MBH
- Larger heating loads that still fit the 18.5 x 11.5 in small chassis
- Owners who want the 10.9 sq ft heat exchanger in a heating-only package
Applicability and support
- Model number
- IP120S
- Canadian availability
- available
- Production status
- current
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Series terms
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Specifications
Published specifications
Values as published by Rinnai. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Heating input, minimum | 15 MBH | Space-heating input; 15,000 BTU/h minimum input per spec Table 2. |
| Heating input, maximum | 120 MBH | Space-heating (CH) maximum input per spec Table 2. |
| Efficiency | ||
| Efficiency (AFUE) | 96 % | Up to 96% AFUE per Rinnai Canada marketing copy and the Canadian brochure; no per-model AFUE figure is printed in the I&O manual spec tables. |
| Domestic hot water | ||
| Domestic hot water | Heating-only boiler; domestic hot water via an indirect tank | No DHW connections on the solo (spec Table 3); indirect-tank setting range 120°F-150°F (50°C-65°C) per spec Table 2. |
| Venting and air | ||
| Venting | 2" nominal PVC/polypropylene or 3" x 5" concentric | Vent connection per the I&O manual; direct-vent (concentric or twin-pipe) and room-air options are covered in the manual's venting section. |
| Max. equivalent vent length, 2" | 75 ft | Twin-pipe 2" PVC / 2" PP maximum equivalent length per the solo I&O manual (Table 20). |
| Max. equivalent vent length, 3" | 160 ft | Twin-pipe 3" PVC / 3" PP maximum equivalent length per the solo I&O manual (Table 20). |
| Physical and connections | ||
| Weight | 64.8 lb | 64.8 lb (29.4 kg) per the I&O manual spec Table 2. The product page prints 112.4 lb (50.9 kg) — that value matches the IP175S/IP199S manual weight, so the page figure is treated as a copy error and the manual value is used here. |
| Water content (CH) | 0.88 gal | Central-heating water content per spec Table 2. |
| Gas connection | 3/4" NPT | Per spec Table 3. |
| Heating water connections | 1" NPT | CH supply and return per spec Table 3. |
| Width | 18.5 in (470 mm) | Per the I&O manual dimension figure and the product page. |
| Depth | 11.5 in (291 mm) | Per the I&O manual dimension figure; the product page lists 292.1 mm. |
| Operating limits and other | ||
| Fuel | Natural gas or propane | Gas supply pressure per spec Table 2: NG 3.5-10.5 in. W.C. (0.87-2.61 kPa); propane 8.0-13.5 in. W.C. (1.99-3.36 kPa). |
| CH water pressure | 13 – 45 psi | Minimum 13 PSI (90 kPa), maximum 45 PSI (310 kPa); recommended 17-26 PSI; 30 PSI pressure relief valve included with the system (spec Table 2). |
Manuals
Alerts documented for this model
Frequently asked questions
Why does Boilers.ca list 64.8 lb when the Rinnai page says 112.4 lb?
The I&O manual spec table (doc 800000191(02)) prints 64.8 lb (29.4 kg) for the IP120S. The product page's 112.4 lb is the same figure the manual prints for the IP175S/IP199S solos, so it appears the page copied the large-solo weight; the manual value is used and the conflict documented.
What is the largest solo documented in full?
The IP150S. The IP175S and IP199S are sold in Canada but remain draft records here because their English I&O manual is raster-only.
Does the IP120S support an indirect tank?
Yes. It is heating-only with no internal DHW, and the solo I&O manual documents indirect-tank control including tank recovery priority and a simultaneous-operation parameter.
Questions about the Rinnai IP120S?
Describe what the boiler is doing and get a straight answer about the next step.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
- Rinnai Canada — IP120S product page · accessed September 7, 2026
- Rinnai Canada — condensing boilers · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.