Nti 86129 Controller 850MN

Product Description

The NTI 86129 is a replacement controller designed for use with the NTI 850MN boiler series. NTI, known for producing high-efficiency heating equipment, builds these controllers to manage the core operating functions of their condensing boiler systems. The 86129 controller handles ignition sequencing, temperature regulation, and safety shutdown logic that keeps the boiler running within safe and efficient parameters. This type of control board is a critical component in any forced hot water or radiant heating system. When a controller fails, the boiler may lock out, fail to ignite, or cycle incorrectly. Replacing it with the correct OEM part restores normal operation and avoids the risks associated with using mismatched components. HVAC technicians and heating contractors working on NTI 850MN units will find the 86129 to be a direct fit replacement. One important installation note: for NTI Tx models with a serial number prior to 72171, an external spark kit with part number 85040 is required in addition to this controller. Technicians should verify the unit serial number before ordering to determine whether the spark kit is needed. This ensures the ignition system is fully compatible and that the boiler will fire correctly after installation. The 86129 is an OEM-specified part, meaning it is built to the same tolerances and specifications as the original component installed at the factory. Using the correct OEM controller helps maintain the efficiency ratings, warranty considerations, and safety certifications associated with the 850MN boiler. Trade professionals replacing failed or damaged control boards on NTI heating systems should confirm compatibility with the unit serial number before installation.

• Replacement controller for NTI 850MN boiler series
• Manages ignition sequencing, temperature control, and safety shutdown functions
• For Tx models with serial number prior to 72171, external spark kit 85040 is required

Product Highlights

The NTI 86129 is an OEM replacement controller for the 850MN boiler, designed to restore correct ignition, temperature regulation, and safety control functions. Technicians should verify the unit serial number to determine if spark kit 85040 is also needed.

Product Information

Standard Information

• Brand: NTI
• Manufacturer Part Number: 86129

Technical Specifications

• Compatible Model: NTI 850MN Boiler Series
• Component Type: Boiler Controller
• Installation Note: For Tx models prior to serial number 72171, external spark kit 85040 is required