The Intellihot Neuron Series is the first drop-in ready tankless water heater designed specifically to replace commercial tank and boiler installations — no re-piping required, 50% faster installation, and the same piping connections as a traditional tank for a familiar, straightforward changeover. Three models cover the full range of commercial replacement applications: the iN199 at 199,950 BTU/h, the iN401 at 399,999 BTU/h, and the iN501 at 499,999 BTU/h. All three are floor-mounted, fully modulating, condensing, and backed by Intellihot's patented Masterless Cascading technology. This guide covers every spec, every feature, and everything you need to know before specifying the Neuron Series on your next commercial replacement project.
PlumbersCrib.com carries all three Neuron Series models. Browse the Neuron Series at PlumbersCrib.com or contact our team for help sizing the right model for your project.
What makes the Neuron Series different
Drop-in ready — no re-piping required. The Neuron Series is designed to mimic the piping connections of traditional tank water heaters, with water in and out connections in the same locations as the units they replace. When replacing a comparable tank-type unit, no re-piping is required — the Neuron drops in and connects to existing supply and return lines. Intellihot guarantees the Neuron Series will replace comparable tank-type units and maintains an online finder at intellihot.com to identify eligible replacement models.
50% faster installation. The familiar piping connection design cuts installation time by 50% compared to a standard tankless retrofit. For commercial service contractors, this means less time on site, lower labor cost, and faster return to hot water service for the building.
Lightning-fast lead times. The Neuron Series ships quickly from readily available stock — no month-long delays waiting for equipment. For emergency replacements where the existing tank has failed, the Neuron Series is the right specification.
Built-in redundancy on iN401 and iN501. The iN401 and iN501 come with two separate, independently controlled heat engines within a single unit — eliminating the need and expense of a redundant backup water heater. If one heat engine requires service, the other continues to operate. This internal redundancy is unique to the Neuron Series and is not available on competing commercial tankless units.
Lightweight and maneuverable. At 266 lbs (iN199) and 345 lbs (iN401/iN501), the Neuron Series units can be transported without heavy machinery and fit through standard elevator doors — a critical advantage in multi-story commercial buildings where getting equipment to the mechanical room requires navigating tight corridors, stairwells, and elevators.
7" color touchscreen. Every Neuron Series unit includes a 7" color touchscreen providing access to usage data, troubleshooting, and parts wear status — directly on the unit, without requiring a separate monitoring device or laptop connection.
telliCare connectivity. Factory monitoring via telliCare LTE cellular messaging — no building Wi-Fi required. Over-the-air software updates and backups keep every unit current without a service visit.
Gas and water pressure sensors. Built-in gas pressure sensor simplifies ignition troubleshooting. Built-in water pressure sensor allows for scaling checks without external instruments.
Low gas pressure operation. The Neuron Series operates on standard low gas pressure — down to 2.5" WC for natural gas — without any reduction in capacity. No high-pressure gas supply required.
Flexible-floating heat exchanger design. Stress-relieving and thermal shock resistant — engineered for the temperature cycling demands of commercial hot water applications.
Automatic pump control. Runs only when there is flow to the unit, preventing pump burnout.
ASME certified. The iN199A, iN401, and iN501 carry ASME certification for additional peace of mind on projects where ASME compliance is required.
iN199 vs iN199A. The iN199 and iN199A are identical in performance and specifications. The iN199A adds ASME certification — the right specification for projects where ASME compliance is a requirement. For projects where ASME certification is not required, the iN199 and iN199A perform identically.
iN199 — 199,950 BTU/h
iN401 — 399,999 BTU/h
iN501 — 499,999 BTU/h
Full specifications
Which Neuron model is right for your project
iN199 / iN199A — the right choice for replacing smaller commercial tank units in the 100,000–200,000 BTU/h range. At 98% thermal efficiency it is the most efficient unit in the entire Intellihot lineup. The iN199A adds ASME certification for projects where compliance is required. A 4-unit iN199 cascade delivers 799,800 BTU/h for larger applications.
iN401 — the most popular Neuron model and the most common drop-in replacement for aging commercial boiler installations. At 399,999 BTU/h with dual internal heat engines, ASME certification, and 4-unit cascade capability up to 1,600,000 BTU/h, the iN401 covers mid-size hotels, apartment buildings, schools, and commercial facilities with moderate to high hot water demand.
iN501 — the highest output Neuron model at 499,999 BTU/h. ASME certified, dual internal heat engines, and 4-unit cascade capability up to 1,999,996 BTU/h. The right specification for larger commercial replacement projects where maximum per-unit output and internal redundancy are both required.
Masterless Cascading on the Neuron Series
Up to 4 Neuron Series units can be cascaded with common venting — no master controller required. Intellihot's patented Masterless Cascading means every unit in the cascade operates independently. If one unit goes offline for service, the remaining units regroup and continue to operate. Combined with the built-in dual heat engine redundancy on the iN401 and iN501, a cascaded Neuron Series installation provides multiple layers of redundancy that a traditional tank installation simply cannot match.
Frequently asked questions
Does the Neuron Series really drop in without re-piping?
Yes — the Neuron Series is designed with water in and out connections in the same locations as comparable traditional tank units. Intellihot guarantees the Neuron will replace eligible tank-type units. Use the replacement finder at intellihot.com to confirm your specific existing unit qualifies before ordering.
What is the difference between the iN199 and iN199A?
Performance and specifications are identical. The iN199A adds ASME certification for projects where compliance is required. Both carry the same 199,950 BTU/h max input, 98% thermal efficiency, and 266 lb weight.
What does built-in redundancy mean on the iN401 and iN501?
The iN401 and iN501 each contain two separate, independently controlled heat engines within a single unit. If one heat engine requires service, the other continues to operate — the unit stays online and producing hot water throughout the service event. This eliminates the need for a separate redundant backup water heater.
Can the Neuron Series fit through a standard elevator door?
Yes — the 20" × 20" footprint and weights of 266 lbs (iN199) and 345 lbs (iN401/iN501) are designed specifically to fit through standard elevator doors and navigate tight mechanical room corridors without heavy machinery.
What fuel does the Neuron Series run on?
Natural gas with LP field conversion available. NG static gas pressure 2.5"–14" WC, LP 8"–14" WC.
Does the Neuron Series require building Wi-Fi for connectivity?
No — telliCare monitoring uses LTE cellular connectivity built into every unit. No building Wi-Fi or network integration required.
Shop Intellihot Neuron Series at PlumbersCrib.com
- iN199 — 199,950 BTU/h, 98% efficiency, 266 lbs, 3" vent
- iN401 — 399,999 BTU/h, 96% efficiency, 345 lbs, 4" vent, ASME certified
- iN501 — 499,999 BTU/h, 96% efficiency, 345 lbs, 4" vent, ASME certified
Browse the full Intellihot lineup at PlumbersCrib.com. Contact our team or call 877-881-5501 Monday through Friday for help sizing the right Neuron Series model for your project.