Changing The Orifice - NTI Trinity Tft285 Instructions

1.0 Changing the Orifice

1. Turn the 120VAC power supply off to the boiler.
2. Turn gas supply "shut off valve" off.
3. Remove the front cover from the unit.
4. Remove feedback hose between Air-inlet Pipe and Gas Valve.
5. Loosen the gear clamp at the coupling securing the Air-inlet Pipe to the Venturi; remove Air-inlet Pipe from
boiler.
6. Disconnect the gas line at the union fitting at the inlet to the Gas Valve.
7. Remove the three screws securing the Venturi/Gas Valve assembly to the Combustion Blower, remove
Venturi/Gas Valve assembly from the boiler.
8. Disconnect the Gas Valve by removing the three screws securing it to the Venturi.
9. Remove the rubber gasket located between the Gas Valve and Venturi and insert the 5.2 mm LP-orifice into the
groove in the middle of the gasket; the orifice should fit securely.
10. Seat gasket (w/orifice) into the outlet of the Gas Valve, and re-attach the Gas Valve to the Venturi and securely
tighten the three screws.
11. Reassemble the Venturi/Gas Valve assembly to the Combustion blower; ensure the Venturi to Combustion blower
gasket is aligned and in good condition. Securely tighten the three screws.
12. Reconnect the gas line at the union fitting and tighten securely while supporting both sides of the fitting.
13. Reinstall the Air-inlet Pipe and secure with gear clamp to Venturi; make certain the rubber coupling is properly
aligned with Venturi and Air-inlet Pipe.
14. Reconnect the feedback hose between Air-inlet Pipe and Gas Valve.
15. Turn gas on and check for leaks.
Combustion Blower
2
Figure 1-1 LP-Orifice and Throttle/Input Screw Adjustment
Throttle / Input Adjustment Screw
DO NOT Adjust
Rubber Gasket
Venturi
Tft285 NG-LP Conversion Instructions
Line Pressure Test Port
Gas Valve
LP-orifice
Air-inlet
Pipe