NTI Boiler: 3-way valve motor must be disconnected for heating-only use on TRX150 / TRX199
3-way valve motor must be disconnected for heating-only use on TRX150 / TRX199 on a NTI boiler: If the boiler only serves heating and is not connected to an indirect water heater, the 3-way valve motor must be disconnected while the boiler runs in central heating mode. This locks the valve in CH so freeze protection works. Leaving the valve connected can disable freeze protection and cause property damage.
Applies to: TRX150 and TRX199 models, heating-only installs
How to fix 3-way valve motor must be disconnected for heating-only use on trx150 / trx199: step by step
- Confirm the boiler is heating only, with no indirect water heater.
- Disconnect electrical power before working on the wiring.
- Disconnect the 3-way valve motor so it stays locked in central heating mode.
If the unit shows an error code, look it up: NTI Boiler codes
Models
TRX085TRX110CTRX150TRX199TRX199C
Source: NTI TRX150 manual, p. 9. 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.