NTI Boiler: Replace the main heat exchanger
Replace the main heat exchanger on a NTI boiler: Drain the boiler and disconnect the heating piping, relief valve pipe, air purger and return pipe before removing the heat exchanger.
Applies to: TRX150
How to fix replace the main heat exchanger: step by step
- Drain the boiler and remove the combustion assembly.
- Remove the exhaust vent adapter on top of the boiler.
- Remove the two screws holding the CH relief valve pipe assembly to the top of the boiler.
- Remove the three clips on the automatic air purger, then remove the CH relief valve pipe.
- Disconnect the bottom of the heating supply pipe from the hydraulic group and from the air purger.
- Remove the automatic air purger from the heat exchanger.
- Disconnect the return pipe from the top of the pump, remove its clip and remove it from the boiler.
- Remove the condensate pipe as needed.
- Remove the six fixing screws from the heat exchanger. Remove the lateral panel if the left screws are hard to reach.
- Install the new heat exchanger, replace all sealing rings, and check for gas leaks.
Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.
If the unit shows an error code, look it up: NTI Boiler codes
Source: NTI TRX150 manual, p. 99-100. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.