Rheem / Ruud (commercial) · IKONIC Commercial Condensing Tankless
Rheem RTGH-CSR11i
The Rheem RTGH-CSR11i is the recirculation version of the IKONIC Commercial Condensing Tankless water heater — a commercial DHW-only appliance rated 11,000–199,900 BTU/h, 11.2 GPM and 0.96 UEF, not a boiler.
Key figures
- Max input
- 199,900 BTU/h
- Max CSA output
- —
- AFUE
- —
- Min input
- 11,000 BTU/h
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Rheem RTGH-CSR11i in practice
Per the official Rheem brochure and the shared RTGH-CS(R)11i specification sheet, the RTGH-CSR11i fires from 11,000 to 199,900 BTU/h on natural gas or propane, delivers up to 11.2 GPM at a 35°F rise (8.8 GPM at 45°F, 5.9 GPM at 67°F), is rated 0.96 UEF and is ENERGY STAR qualified. It installs indoors as standard, with the RTGH-SX outdoor conversion kit sold separately, and operates at altitudes up to 10,200 ft without component changes.
The RTGH-CSR11i carries a built-in recirculation pump for no-wait hot water at the tap, with a maximum recirculation loop of 400 ft on 3/4" pipe or 100 ft on 1/2" pipe. It weighs 86 lb and shares the same cabinet, ratings, connections and warranty as the base model.
The unit is a down-fire, pre-mix sealed-combustion water heater with a 444 stainless-steel tube-fin primary heat exchanger and a brazed-plate 304 stainless-steel secondary, a threaded condensate trap, and manifold capability up to 32 units with common venting up to 12. It is certified to CSA/ANSI Z21.10.3:19 and carries an 8-year limited heat-exchanger, 5-year parts and 1-year labor warranty. This is a domestic-hot-water appliance, not a boiler; Rheem-family commercial boilers are the Raypak lines.
Best suited to
- Commercial domestic hot water at up to 199,900 BTU/h per unit
- Buildings wanting no-wait recirculated hot water from a factory pump
- Manifolded plants: up to 32 units without external control, common venting up to 12
Applicability and support
- Model number
- RTGH-CSR11i
- Canadian availability
- unknown
- Production status
- current
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Not verified
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 Rheem / Ruud (commercial). Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input, maximum | 199,900 BTU/h | As printed in the official Rheem/Ruud brochures and the RTGH-CS(R)11i specification sheet (Rev. 01, 11-14-2025). |
| Input, minimum | 11,000 BTU/h | |
| Efficiency | ||
| Uniform Energy Factor (UEF) | 0.96 UEF | 0.96 UEF; ENERGY STAR qualified per the official product pages and brochures. |
| Domestic hot water | ||
| Flow at 35°F rise | 11.2 GPM | |
| Flow at 45°F rise | 8.8 GPM | |
| Flow at 67°F rise | 5.9 GPM | |
| Minimum activation flow | 0.4 GPM activation / 0.26 GPM continuous | |
| Venting and air | ||
| Venting | Schedule 40 PVC, CPVC or polypropylene; 2" or 3"; 70 ft (2") / 150 ft (3") single run; common vent up to 12 units | |
| Physical and connections | ||
| Weight | 86 lb | As printed in the official brochure model table. |
| Heat exchanger | Primary: 444 stainless steel tube-fin; secondary: brazed-plate 304 stainless steel | Per the RTGH-CS(R)11i specification sheet; the brochures summarize as stainless/stainless. |
| Dimensions (H × W × D) | 28-9/16 × 17-5/16 × 13-11/16 in | |
| Electrical | ||
| Power supply | 120 V, 60 Hz | |
| Operating limits and other | ||
| Recirculation | Built-in recirculation pump | Recirculation loop up to 400 ft on 3/4" pipe or 100 ft on 1/2" pipe. |
| Temperature range | 85°F – 185°F (factory setting 120°F; max inlet return 140°F) | |
| Fuel | Natural gas or LP; ships NG with LP conversion kit included | |
| Installation | Indoor; outdoor conversion kit RTGH-SX sold separately | |
| Maximum altitude | 10,200 ft without component changes | |
| NOx | Ultra-Low NOx, meets 14 ng/J; SCAQMD Rule 1146.2 compliant | |
| Manifold capability | Up to 32 units without external control | |
| Warranty | 8-year limited heat exchanger / 5-year limited parts / 1-year limited labor | |
Manuals
Alerts documented for this model
None documented yet.
Frequently asked questions
Is the RTGH-CSR11i a boiler?
No. It is a commercial condensing tankless water heater (DHW-only). Rheem's commercial product tree contains no boiler category; commercial boilers in the Rheem family are the Raypak lines.
What are the RTGH-CSR11i ratings?
11,000–199,900 BTU/h input, up to 11.2 GPM at a 35°F rise, 0.96 UEF and ENERGY STAR, per the official brochure and specification sheet.
Does this model include a recirculation pump?
Yes. The CSR (Rheem RTGH-CSR11i / Ruud RUTGH-CSR11i) models include a built-in recirculation pump with a maximum loop of 400 ft on 3/4" pipe or 100 ft on 1/2" pipe.
Questions about the Rheem RTGH-CSR11i?
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
- Rheem — IKONIC Commercial Condensing Tankless RTGH-CSR11i product page · accessed September 9, 2026
- Rheem — IKONIC Commercial Tankless Water Heater brochure · accessed September 9, 2026
- Rheem — COMM Condensing Tankless Gas WH Suggested Specification, RTGH-CS(R)11i Rev. 01 · accessed September 9, 2026
- Rheem/Ruud — Limited Warranty, Commercial Tankless Gas Water Heaters · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.