⚠️ WARNING: This boiler must be serviced by a qualified heating technician. Failure to properly maintain or service this appliance may result in property damage, serious injury to occupants, or death.
Applicable Boilers:
- Tft60-399
- Vmax110(P)-153(P)
- FTV110(C), 150(C),190(C)
Tools Required:
- Pliers
- Phillips #2 screwdriver
- Flat Screwdriver
- 1/4-inch nut driver or wrench
- 5/16-inch nut driver or wrench (8mm Wrench Optional)
- 10mm wrench
- 1/2-inch Wrench
- 7/16-inch Wrench
- 9/16-inch Wrench
- Pipe wrench
- Torx T25, Torx T20 Screwdriver
- Adjustable wrench
- Household white vinegar
- Stiff bristle nonmetallic scrub brush (Cleaning kit 85259)
Image shows a clean combustion chamber with a star-shaped grate, as seen in TFT or Vmax models.
Image shows a dirty combustion chamber with accumulated residue, as seen in TFT or Vmax models.
Image displays the NTI Boiler Cleaning Kit (Part Number 85259, optional), featuring a stiff, non-metallic scrub brush.
ℹ️ NOTICE: Read these instructions through before beginning your cleaning procedure.
⚠️ WARNING: Allowing any NTI boiler to operate with a dirty combustion chamber will not only adversely affect the operation of the boiler but will also void the warranty. Failure to clean the combustion chamber on a frequency that matches the needs of the application may result in fire, property damage, or death.
Disassembly Instructions (TFT 60-110 used for reference pictures)
Step 1: Preparation
- Turn off power and gas to the boiler.
- Remove top service panel.
- Remove condensate drain from bottom of boiler.
Diagram showing the service panel access secured by four 1/4-inch screws. Text indicates 'DO NOT Block'.
ℹ️ NOTICE: Note the location of the wiring and tubing prior to disassembly.
Step 2: Disconnect Harnesses
- Disconnect the wiring harnesses on the blower motor, flame rod igniter, and gas valve.
Diagram illustrating internal boiler components, highlighting the Gas Valve Harness, Communications Harness, and Power Harness connected to the blower motor.
Step 3: Gas Line and Air Inlet
- Detach the vinyl hose from the gas valve.
- Loosen the MJ coupling and remove the air inlet assembly from the Venturi of the gas valve.
- Disconnect the gas line (gas line union beside the gas valve).
Image shows the gas valve assembly detached, including a vinyl hose, MJ coupling, and gas line union.
Step 4: Component Removal
- Detach the gas valve and Venturi assembly from the blower motor.
- Remove the blower motor and gasket.
- Remove the flame probe and ignition electrode.
Image displays the flame probe and ignition electrode, components removed from the burner assembly.
- Remove the burner plate and burner plate gasket.
- Remove the burner plate ceramic disk.
Image shows the burner plate gasket and the burner plate ceramic disk.
ℹ️ NOTICE: A screwdriver with an 8-inch or 10-inch blade will be required to remove the rear screws on the blower motor on older Tft and Vmax models. Newer Models and FTV models will require a 5/16-inch or 8mm Wrench.
ℹ️ NOTICE: The burner plate and gasket will only fit on the heat exchanger in one position.
Cleaning Procedure
Step 1: Initial Assessment and Preparation
- Photograph or document the condition of the combustion chamber.
- Record the duration from installation to the first cleaning, as this will aid in developing a cleaning schedule.
- Use a vacuum with a high efficiency filter to remove any loose debris or dust. Refer to Refractory Ceramic Fibers in the Installation and Operations Manual for guidance.
- Place a bucket under the condensate drain.
Step 2: Wet Cleaning
- Wet the inside of the combustion chamber with water. Use a garden hose with a trigger nozzle to direct pressurized water through the fire tubes.
- Water should pass through the fire tubes in the heat exchanger and exit via the condensate drain.
- Use dry rags or plastic to protect electrical components from being damaged by dripping or spraying water.
- Allow water to drain through the condensate drain.
Step 3: Scrubbing and Rinsing
- Use the brush from the Cleaning kit, a stiff nylon brush, or other non-metallic brush to loosen the incrustations and any other contaminants that remain on the surface and openings of the fire tubes.
- Continue scrubbing and rinsing with clean water until the water runs clear from the condensate drain.
Step 4: Vinegar Soak
- Soak the combustion chamber with household white vinegar and allow it to sit for 5-10 minutes.
Step 5: Final Rinse
- Scrub the chamber again and then thoroughly flush the combustion chamber with plenty of clean water.
Condensate Trap Cleaning
- Clean the condensate trap.
Image shows the condensate trap, a clear plastic component with an internal ball mechanism.
- Use dry rags for oily or sticky residue. Re-install the trap and pre-charge it with water.
ℹ️ NOTICE: Ensure that the ball in the condensate trap is floating freely prior to leaving the job site. Failure to do so may result in boiler malfunction causing property damage.
Inspection and Reassembly
Step 1: Component Inspection
- Inspect the burner plate ceramic disk and the burner plate gasket for wear and damage.
- Replace any worn or damaged components.
Step 2: Reassembly
- Reassemble in reverse order.
- Torque the nuts on the burner plate to 48 inch-pounds (4 foot-pounds).
- If a torque wrench is not available, tighten the burner plate nuts until the burner plate gasket bulges slightly.
Burner Plate Gasket: Do not over-tighten the burner plate nuts. This could result in gasket failure and a gas leak. This may result in fire, property damage, or death.
Step 3: Post-Reassembly Checks
- After reassembly, perform the following checks for leaks:
- With gas turned off, disconnect the communications harness (5-pin connector) from the blower motor. This will cause the blower motor to run at high speed.
- Then temporarily block the exhaust vent.
- Use a mixture of soap and water to check for leaks throughout the boiler assembly.
- Confirm there are no leaks, then remove the blockage from the exhaust vent and reconnect the communication wire harness to the blower.
- Check for proper operation including smooth ignition.
- Perform a combustion analysis (refer to the Installation and Operations Manual).
Parts for Service: Refer to the parts list in the Installation and Operations Manual.
