Therm [Marquis Spas] 12" 4.0kW Flow-Thru Incoloy Heater (26-C2278-1-5S-K)

Therm [Marquis Spas] 12" 4.0kW Flow-Thru Incoloy Heater (26-C2278-1-5S-K) is designed as a purpose-focused replacement heater for Marquis Spas, where matching physical configuration and heating output is essential to dependable spa operation. Its 4.0kW heating output and 12" heater length should be matched to the original equipment requirements before installation, since spa heaters are not universally interchangeable.

In day-to-day spa operation, a properly matched heater helps eliminate slow recovery, erratic temperature maintenance, and nuisance shutdowns that can occur when the replacement does not correspond to the original system requirements. This model's specified 4.0kW output is intended to deliver predictable heat when paired with the correct control system, plumbing arrangement, and electrical configuration.

Its Incoloy heating element construction provides a proven balance of heat-transfer performance, durability, and dependable service in properly maintained spa water. The 12" format helps preserve the intended plumbing alignment and equipment-bay fit when replacing a compatible original assembly. Together, these design details help the heater integrate correctly with the surrounding circulation and control components rather than functioning as an isolated replacement part.

Installation is most successful when the original heater dimensions, wattage, terminal arrangement, plumbing unions, and equipment clearances are verified before removal. Once correctly matched and installed, the heater can support stable temperature maintenance and dependable day-to-day spa use.

For spa owners, the result is straightforward: more dependable heat, fewer interruptions, and a replacement that is selected around the system's actual requirements.

• Application-focused replacement design for Marquis Spas
• 4.0kW rated heating output
• 12" heater configuration for proper fitment
• Incoloy element construction for dependable heat transfer
• Supports reliable temperature recovery when correctly matched and installed