Not every tankless job calls for a condensing unit. The Rheem RTG Series is the non-condensing tankless lineup contractors reach for when they need a proven, efficient, easy-to-install unit — designed with contractors in mind from the ground up. Up to 10% smaller and 22% lighter than the previous generation, with industry-best 1/2" side-to-side clearance and universal venting compatibility, the RTG Series is built for retrofits and new construction alike. This guide covers every model, confirmed specs, and everything you need to know before you order.
PlumbersCrib.com is an authorized Rheem dealer. Browse the full Rheem RTG lineup at PlumbersCrib.com or contact our team with sizing or spec questions.
RTG vs. IKONIC — when to spec which
Rheem makes two distinct tankless lineups — the condensing IKONIC series (0.96 UEF, dual stainless steel heat exchangers, 15-year warranty) and the non-condensing RTG series (0.82 UEF, copper heat exchanger, 15-year warranty). Here is when each one makes sense:
Spec the RTG when: the client has a budget that does not support a condensing unit, the installation is a direct tankless-to-tankless replacement where existing venting is already in place, the job is in a warm climate where the efficiency difference between condensing and non-condensing is less significant, or the installation requires outdoor placement where a non-condensing outdoor unit is the simplest solution.
Spec the IKONIC when: the client wants maximum efficiency (0.96 UEF), built-in recirculation (SR models), the longest available warranty, or is in a cold northern climate where the efficiency difference between condensing and non-condensing is most pronounced and most valuable.
Key difference to know: The RTG series uses a copper heat exchanger — not the dual stainless steel exchangers of the IKONIC. Both carry a 15-year heat exchanger warranty, but in hard water areas the stainless steel exchangers in the IKONIC are more resistant to scale and corrosion long-term. For hard water sites, either specify the IKONIC or ensure a water treatment system is in place upstream of the RTG unit.
Full specifications — confirmed from official Rheem spec sheet
All specs below are pulled directly from the official Rheem RTG/RTG-R Series spec sheet (Form No. RH-RTG-RTGR-SS Rev.1, 02/26). All models are available in natural gas (N) or propane (P) — swap P for N in the model number for propane.
Indoor models
| Model Number | RTG-70 DVLN-3 | RTG-84 DVLN-3 | RTG-95 DVLN-3 | RTG-95 DVELN-3 | RTG-R70 DVELN-3 | RTG-R95 DVELN-3 | |
|---|---|---|---|---|---|---|---|
| Gas Input Rate | Maximum | 160,000 BTU/h | 180,000 BTU/h | 199,900 BTU/h | 199,900 BTU/h | 160,000 BTU/h | 199,900 BTU/h |
| Minimum | 11,000 BTU/h — all models | ||||||
| Built-in Recirculation | Sold Separately | Yes | Yes | ||||
| Built-in Wi-Fi | — | — | — | Yes | Yes | Yes | |
| Built-in LeakGuard | — | — | — | Yes | Yes | Yes | |
| Uniform Energy Factor (UEF) | 0.82 — all models | ||||||
| Gallons Per Minute (GPM) | Maximum (35°F rise) | 7.0 | 8.4 | 9.5 | 9.5 | 7.0 | 9.5 |
| 45°F Rise | 6.0 | 6.7 | 7.4 | 7.4 | 6.0 | 7.4 | |
| 67°F Rise | 4.5 | 5.1 | 5.0 | 5.0 | 4.5 | 5.0 | |
| Number of Bathrooms | 2.5 | 3 | 3.5 | 3.5 | 2.5 | 3.5 | |
| Temperature Range | 100°F – 140°F | ||||||
| Height | 24.2" | 25.5" | |||||
| Width | 13.5" — all models | ||||||
| Depth | 10.27" | 11.2" | |||||
| Weight | 46.5 lbs. | 53 lbs. | |||||
| Maximum Altitude | 7,800 ft. | 10,200 ft. | |||||
| Factory Temperature Setting | 120°F | ||||||
| Heat Exchanger Material | Copper | ||||||
| Minimum Activation Flow | 0.4 GPM | ||||||
| Minimum Continuous Flow | 0.26 GPM | ||||||
| Manifold Controls (maximum units) | 6 units via standard RJ11 communication cables | ||||||
| Ultra Low NOx | Meets 14 ng/J NOx requirements — SCAQMD Rule 1146.2 compliant | ||||||
| Warranty | 15-year heat exchanger | 5-year parts | 1-year labor | ||||||
Outdoor models
| Model Number | RTG-70 XLN-3 | RTG-84 XLN-3 | RTG-95 XLN-3 | RTG-95 XELN-3 | RTG-R70 XELN-3 | RTG-R95 XELN-3 | |
|---|---|---|---|---|---|---|---|
| Gas Input Rate | Maximum | 160,000 BTU/h | 180,000 BTU/h | 199,900 BTU/h | 199,900 BTU/h | 160,000 BTU/h | 199,900 BTU/h |
| Minimum | 11,000 BTU/h — all models | ||||||
| Built-in Recirculation | Sold Separately | Yes | Yes | ||||
| Built-in Wi-Fi | — | — | — | Yes | Yes | Yes | |
| Built-in LeakGuard | Not available on outdoor models | ||||||
| Uniform Energy Factor (UEF) | 0.82 — all models | ||||||
| Gallons Per Minute (GPM) | Maximum (35°F rise) | 7.0 | 8.4 | 9.5 | 9.5 | 7.0 | 9.5 |
| 45°F Rise | 6.0 | 6.7 | 7.4 | 7.4 | 6.0 | 7.4 | |
| 67°F Rise | 4.5 | 5.1 | 5.0 | 5.0 | 4.5 | 5.0 | |
| Number of Bathrooms | 2.5 | 3 | 3.5 | 3.5 | 2.5 | 3.5 | |
| Temperature Range | 100°F – 140°F | ||||||
| Height | 20.75" | 22.03" | |||||
| Width | 13.5" — all models | ||||||
| Depth | 9.4" | 10.7" | |||||
| Weight | 42 lbs. | 47 lbs. | |||||
| Maximum Altitude | 7,800 ft. | 10,200 ft. | |||||
| Factory Temperature Setting | 120°F | ||||||
| Heat Exchanger Material | Copper | ||||||
| Minimum Activation Flow | 0.4 GPM | ||||||
| Minimum Continuous Flow | 0.26 GPM | ||||||
| Manifold Controls (maximum units) | 6 units via standard RJ11 communication cables | ||||||
| Ultra Low NOx | Meets 14 ng/J NOx requirements — SCAQMD Rule 1146.2 compliant | ||||||
| Warranty | 15-year heat exchanger | 5-year parts | 1-year labor | ||||||
GPM by climate zone — size for your region
The RTG's published GPM figures are at a 35°F rise — the industry standard for comparison. In colder climates where temperature rise requirements are higher, effective GPM drops significantly. Use the flow rate by zone table below — all figures confirmed from the official Rheem spec sheet at 120°F set temperature, 105°F mixed shower temperature.
| Model | Zone 1 (37°F) | Zone 2 (42°F) | Zone 3 (47°F) | Zone 4 (52°F) | Zone 5 (57°F) | Zone 6 (62°F) | Zone 7 (67°F) | Zone 8 (72°F) | Zone 9 (77°F) |
|---|---|---|---|---|---|---|---|---|---|
| RTG-95 / RTG-R95 | 4.0 | 4.3 | 4.6 | 4.9 | 5.3 | 5.7 | 6.3 | 6.9 | 7.7 |
| RTG-84 | 3.6 | 3.8 | 4.1 | 4.4 | 4.8 | 5.2 | 5.7 | 6.3 | 7.0 |
| RTG-70 / RTG-R70 | 3.2 | 3.4 | 3.7 | 3.9 | 4.2 | 4.6 | 5.0 | 5.6 | 6.2 |
Cold climate contractor note: In Zone 1–3 states (Minnesota, Wisconsin, Michigan, New England, northern mountain states), even the RTG-95 delivers only 4.0–4.6 GPM. For a home running a shower plus one other fixture simultaneously in a cold climate, the RTG-95 is the minimum — and in many cases the condensing Rheem IKONIC S10i or S11i is a better long-term spec. Use the zone table above and have the conversation with your client before finalizing the order.
What contractors need to know: installation details
1/2" side-to-side clearance. This is the industry's tightest side clearance — no other tankless manufacturer matches it. On retrofit jobs where the existing tankless occupied a tight mechanical closet or utility room, the RTG fits where the competition does not. Zero clearance required from the back of the unit to the vent pipe.
Universal venting compatibility. The RTG Series is compatible with Metal Fab, ProTech, and UBBINK standard concentric venting — the three most common venting brands in the field. On a tankless-to-tankless replacement where existing venting is already in place, there is a good chance you can reuse it rather than replacing the entire vent run. Confirm compatibility with the existing vent material before starting.
43 ft. maximum vent run. With zero elbows, the RTG supports 43 ft. of straight 3"/5" pipe. Each 90° elbow reduces the available run by 1.6 ft. equivalent; each 45° elbow by 9 inches. Plan the vent route before ordering to confirm the run is within spec.
Manifold up to 6 units. The RTG Series supports manifolding up to 6 units together via standard RJ11 communication cables (part number RCPN-AMP03-0013111101-0003, 48"). On larger residential or light commercial jobs where a single unit is not enough, this is a straightforward expansion path.
Recirculation options. Built-in recirculation is available on RTG-R models. On non-R models, an external recirculation pump (AP17920) is sold separately and supports a dedicated return line or crossover valve configuration. If the client wants no-wait hot water and you are not speccing an R model, plan the recirculation pump and return line at rough-in.
LeakGuard on indoor Wi-Fi models. LeakGuard is available exclusively on indoor models with built-in Wi-Fi (DVELN and RTG-R DVELN models). It detects any leak originating from the unit and shuts off the water supply automatically. On jobs where water damage risk is a concern — finished basements, upper floor mechanical rooms — the DVELN or RTG-R DVELN models with LeakGuard are worth speccing over the standard DVLN.
EcoNet Wi-Fi. Available on XELN, DVELN, and RTG-R models. Allows the homeowner to control temperature, monitor usage, and receive alerts via the Rheem EcoNet app. Requires a 2.4GHz Wi-Fi network at the installation location.
Which model for which job
RTG-70 series — 7.0 GPM at 35°F rise. Best for small homes (2.5 bathrooms), warm climate jobs (Zone 5–9), or secondary hot water applications. In cold climates (Zone 1–3), delivers only 3.2–3.7 GPM — not adequate for whole-home use.
RTG-84 — 8.4 GPM at 35°F rise. The mid-range option covering 3 bathrooms in warm to moderate climates. In cold Zone 1–2 climates delivers 3.6–3.8 GPM — borderline for whole-home use. Best suited for Zone 4 and warmer.
RTG-95 series — 9.5 GPM at 35°F rise. The top of the non-condensing RTG range, covering 3.5 bathrooms. In cold Zone 1 climates still only delivers 4.0 GPM — confirm with the client that this is adequate for their peak usage before speccing in a northern climate. In Zone 4 and warmer, the RTG-95 handles most whole-home applications comfortably.
RTG-R series — built-in recirculation. Available in RTG-R70 and RTG-R95 configurations, indoor and outdoor. Spec the R model when the client wants no-wait hot water and a dedicated return line is feasible. Saves up to 12,000 gallons of water per year versus standard tankless. Requires EcoNet Wi-Fi for full scheduling functionality.
Frequently asked questions
Can I reuse existing venting on a tankless replacement?
Possibly — the RTG Series is compatible with Metal Fab, ProTech, and UBBINK standard concentric venting, which covers many existing installations. Confirm the existing vent material, diameter, and run length are within spec before assuming it can be reused. Always inspect the vent for damage or buildup before reconnecting.
What is the difference between the DVLN and DVELN models?
DVLN models are indoor direct vent without Wi-Fi or LeakGuard. DVELN models add built-in EcoNet Wi-Fi and LeakGuard. The RTG-R DVELN models further add built-in recirculation. All indoor models use 3"/5" concentric direct vent.
What is the difference between the XLN and XELN outdoor models?
XLN models are outdoor without Wi-Fi. XELN models add built-in EcoNet Wi-Fi. RTG-R XELN models add built-in recirculation. Outdoor models do not include LeakGuard regardless of Wi-Fi status.
Is the RTG-95 adequate for a whole-home installation in a cold northern climate?
In cold Zone 1–2 climates (Minnesota, Wisconsin, northern New England), the RTG-95 delivers only 4.0–4.3 GPM — enough for one shower but tight for simultaneous fixtures. For most cold-climate whole-home installations, the condensing Rheem IKONIC S10i or S11i is the better long-term spec.
Can I manifold RTG units together for higher capacity?
Yes — up to 6 RTG units can be manifolded together using standard RJ11 communication cables (part number RCPN-AMP03-0013111101-0003, 48"). Each unit requires its own dedicated circuit.
Does the RTG work with propane?
Yes — all RTG models are available in natural gas and propane. Swap P for N in the model number for the propane version — for example, RTG-95XLN-3 becomes RTG-95XLP-3 for propane.
Why order from PlumbersCrib.com?
- Authorized Rheem dealer — full manufacturer warranty coverage on every unit
- Full RTG lineup in stock — indoor and outdoor, natural gas and propane, standard and recirculation models
- Free shipping — on all orders over $199 within the contiguous United States
- Technical support — call us at 877-881-5501 Monday through Friday with sizing, spec, or venting questions
Browse the full Rheem RTG lineup at PlumbersCrib.com or contact our team to confirm the right model for your job.