Other: Boiler tips (part 3 of 3)

Short, practical technician tips on other for boiler. Check each one against the manual for your exact model before acting.

Scald risk at DHW temperatures

NTI · NTI TRX150 DHW installations

Water above 125 F can cause severe burns or death. Children, disabled and elderly people are at highest risk. An ASSE 1017 or ASSE 1070 temperature limiting or mixing valve is recommended where those users are present. Mixing valves do not remove the scald risk entirely.

1. Set the water heater setpoint as low as practical.
2. Install a temperature limiting or mixing valve where disabled, elderly or children are served.
3. Advise users to feel the water before bathing or showering.

Scalding water when draining

NTI · TRX150

Water drained from the boiler can be very hot.

1. Let the boiler cool before draining.
2. Take precautions when draining water.

Service clearances and combustible spacing

NTI · TRX boilers, indoor install only

Clearance to combustibles is 0 inches on top, bottom, sides and back. Minimum service clearance is 18 inches front, 14 inches top, 12 inches bottom, 2 inches each side and 0 inches back. A combustible door or removable panel is acceptable at the front, with at least 3 inches from the front cover. Keep 8 inches from high heat sources.

Set date and time manually

NTI · NTI TRX boilers with 365-day clock

Date and time must be correct for time programs to work. If the boiler is on the Wi-Fi app, the Internet time is used automatically. Manual entry only appears when ITIME is OFF.

1. Make sure ITIME is set to OFF in the user menu.
2. Set day (1-31), month (1-12), year and time.
3. Use the hour and minute buttons shown in Figure 57 (items 2 and 8).
4. Press OK to confirm the entered data.

Summer/winter changeover operation

NTI · NTI TRX boilers with user menu 11 and 12 set

With automatic changeover on, the boiler switches from winter to summer mode based on outdoor temperature. Factory switchover temperature is 68 F. If outdoor temperature stays more than 1 F above the switchover temperature for 5 h, the boiler goes to summer mode. If it stays more than 1 F below for 5 h, it returns to winter mode. In summer mode the boiler can turn heating off.

Use the correct gas diaphragm and mixer for the fuel

NTI · TRX150

Install the gas diaphragm and mixer that match natural gas or propane. Propane needs the mixer from the conversion kit.

1. Check the fuel type before fitting the mixer or diaphragm.
2. For propane, install the mixer from the natural gas to propane conversion kit and the gas diaphragm required for propane.
3. Follow the conversion kit instructions.

Vent insulation and material rules near the boiler

NTI · Exhaust vent routing and insulation

Some insulation and pipe materials are not allowed close to the boiler because they can overheat and fail.

1. Do not insulate the first 3 linear feet of exhaust vent.
2. Do not insulate PVC, CPVC or polypropylene exhaust pipe.
3. Use CPVC, polypropylene or stainless steel for the first 3 linear feet if that run passes through an enclosed space longer than 6 inches, such as a wall or ceiling.
4. If you use CPVC or polypropylene or stainless steel for that run, use the same material for the rest of the vent run, except CPVC can be followed by PVC.
5. Do not insulate non-metallic vent pipe or fittings.
6. Keep at least 8 inches from high heat sources at 100°F or more, such as flue pipes or space heaters.
7. Only stainless steel exhaust pipe may be insulated, and a double-wall vent can be used in freezing climates.

Venting material and adapter rules

NTI · Exhaust and intake material compatibility

Mixing materials without the right adapters can let flue gas leak into the living space.

1. Never use B vent for exhaust. It is for intake only.
2. Do not use PVC in the closet or alcove in the US or Canada. Use approved CPVC, polypropylene or stainless steel.
3. When venting with PVC, insert the factory supplied 5 inch length of CPVC into the boiler exhaust connection before transitioning to PVC. Do not insert PVC directly into the boiler exhaust connection.
4. For AL29-4C stainless vent, fit a PVC-to-stainless adapter at the boiler vent connection and at the termination when a PVC termination kit is used.
5. Do not mix AL29-4C from different manufacturers unless the manufacturer's adapters are used.
6. Do not use cellular core PVC, cellular core CPVC or Radel.
7. Do not remove the factory-installed exhaust and intake components near the appliance, or the warranty is void.

Wiring safety: label wires and keep 120 V away from control wiring

NTI · TRX150

Wiring mistakes can cause unsafe operation. Label every wire before disconnecting, and keep 120 V cables separate from low voltage control cables.

1. Label all wires before disconnecting them when servicing.
2. Do not connect 120 V to any control wiring terminal.
3. Use separate cables for 120 V and low voltage control circuits.