Toyotomi OM-128HH - User Manual

Other manuals for Toyotomi OM-128HH

Questions and Answers

K
kellyrobertAug 15, 2025
What to do if my Toyotomi Water Heater operation lamp blinks?
- J
  James HaleAug 15, 2025
  If the operation lamp on your Toyotomi Water Heater is blinking, the short-circuit terminal of timer connection “L” on the circuit board might be disconnected. Connect the short-circuit terminal correctly. Alternatively, the unit may be in a stand-by state due to the automatic operation of the timer, which is normal.
C
Cathy DeanAug 18, 2025
What to do if my Toyotomi Water Heater is extinguished after ignition?
- T
  Tracy ReyesAug 18, 2025
  If your Toyotomi Water Heater extinguishes after ignition, it could be due to several reasons. The flame sensor might be dirty and needs cleaning, or it could be malfunctioning and needs replacement. There might be a fuel restriction, in which case you should remove any air. Also, check the flame sensor and clean it if it is dirty.
A
Amber MedinaAug 21, 2025
How to fix a Toyotomi Water Heater when the blower motor operates but there is no ignition?
- G
  Gina WattsAug 21, 2025
  If the blower motor in your Toyotomi Water Heater is running but there's no ignition, check the fuel level; refuel if necessary. Also, there might be an air pocket in the fuel line that needs to be removed, or the fuel strainer might be clogged and needs cleaning. If there is abnormal lowering of electrical voltage, contact electricians.
D
danielmooreAug 25, 2025
What to do if my Toyotomi Water Heater power lamp fails to turn on?
- M
  Marcus CowanAug 26, 2025
  If the power lamp on your Toyotomi Water Heater doesn't turn on, the power supply cord might be disconnected. Make sure to connect the power supply cord.
J
James VillanuevaAug 28, 2025
Why is my Toyotomi Water Heater making noise from the fuel pump?
- C
  Casey DavisAug 28, 2025
  If your Toyotomi Water Heater's fuel pump is making noise, it could be due to an air lock in the fuel line. Try removing the air to resolve the issue.
C
Caitlyn YoungAug 31, 2025
Why is my Toyotomi Water Heater accumulating soot?
- H
  Haley PattersonAug 31, 2025
  Soot accumulation in your Toyotomi Water Heater can be caused by improper installation of the flue pipe, so re-install it properly. Also, a fuel nozzle failure can cause soot accumulation, so replace it.
C
carlosstewartSep 4, 2025
Why is my Toyotomi Water Heater combustion noisy?
- W
  williamsvalerieSep 4, 2025
  Noisy combustion in your Toyotomi Water Heater can be caused by a fuel nozzle failure, so replace it. Also, if the flue pipe is improperly installed, re-install it properly.
D
David VasquezSep 7, 2025
What to do if hot water temp is too low in Toyotomi Water Heater?
- G
  Gina GilbertSep 7, 2025
  If the hot water temperature from your Toyotomi Water Heater is too low and the hot water supply is beyond capacity, close the hot water faucet partially.
A
Alan PattonSep 12, 2025
What to do if there is water leakage from my Toyotomi Water Heater?
- M
  Melissa GomezSep 12, 2025
  If there's water leakage from your Toyotomi Water Heater, it could be due to a gasket malfunction. In this case, replace the gasket.

The provided manual describes the TOYOTOMI OM-128HH (Type B) Oil-Fired Water Heater for Hydronic Heating. This device is designed for indoor use only and is intended for hydronic heating applications, not for hot water supply.

Function Description

The OM-128HH is an oil-fired water heater that utilizes an oil pressure vapor system for combustion. It can be installed as either a direct vent or chimney vent system. The unit heats water for hydronic heating, with automatic operation based on the temperature of the water inside the heat exchanger. It features a power switch, operation lamp, burner lamp, and a warning lamp to indicate status and potential issues. A temperature selector knob allows users to adjust the hot water temperature. The unit is also equipped with a timer connection terminal for automatic operation, allowing it to enter a stand-by condition when the timer is off and resume operation when the timer is on.

Important Technical Specifications

Model: OM-128HH (Type B)
Type: Oil Pressure Vapor System, Direct Vent or Chimney Vent, Hydronic Heating
Ignition: High Voltage Discharge Spark
Fuel: ASTM D3699 1-K Kerosene, ASTM D396 Low Sulfur No.1 or No.2 Fuel Oil, or ASTM D975 Ultra Low Sulfur Diesel (ULSD). Low sulfur fuel is recommended.
Steady-State Efficiency: 87.0%
AFUE: 87.1%
Hot Water Input: 148,000 BTU/h (Input value of No.1 Fuel Oil)
Fuel Consumption: 1.05 gal/h
Heat Exchanger Capacity: 5.10 gal
Fuel System: External tank (to be purchased from local suppliers)
Dimensions (W x H x D): 12-5/8" x 27-3/4" x 22-1/2"
Weight: 77 lbs. Empty
Vent Pipe Hole: 4-3/4" diameter
Maximum Length of Vent Pipe System: 10 ft., 3 bends or less
Electrical Rating: 120 Volts AC, 60 Hz; Ignition - 136W; Burning - 107W
Exhaust Air Temperature: Less than 350°F
Nozzle: 0.85 GPH, 60°, Delavan Type XA
Temperature Fuse: 282°F
Electric Current Fuse: 5 A, 7A
Water Quality: Circulating water should contain proper quantity of antifreeze solution. pH 6.5 to 8.5, Chloride max 0.0067 Oz/gal (50 mg/L), Hardness max 0.0208 Oz/gal (150 mg/L), Residual Chlorine max 0.00027 Oz/gal (2 mg/L).
Altitude Limit: Designed for use no more than 4,922 FT. (1,500 m) above sea level. Burner adjustments are required at higher altitudes.

Usage Features

The OM-128HH is designed for ease of operation with several safety features.

Temperature Control: A temperature selector knob allows adjustment of hot water temperature from around 70°F (COLD) to 180°F (VERY HOT). The factory setting is approximately 130°F. Users are warned about the risk of scald injury with higher temperature settings.
Power Control: A simple power switch turns the unit ON/OFF. When operating for the first time or after running out of fuel, air in the fuel line may prevent ignition, requiring a specific air removal procedure.
Timer Operation (Option): The unit can be connected to an external timer. When the timer sends an "ON" signal, the unit operates automatically. When the timer sends an "OFF" signal, the unit enters a stand-by mode.
Freeze Prevention: It is crucial to protect hot water piping, drain pipe, check valve, valves, expansion tank, and temperature & pressure relief valve with sufficient insulation or a freeze prevention heater, especially in cold regions. The circulation water should contain adequate antifreeze fluid, which should be changed every 2 years.
Long Term Inactivity: For extended periods of disuse, the heat exchanger and pipes should be thoroughly drained, and the electrical cord disconnected.

Maintenance Features

Routine maintenance is essential for efficient and safe operation.

Pre-Operation Inspection: Before turning on, ensure the water supply inlet is open, check for water leaks, sufficient fuel, proper power connection and grounding, clear area around the heater from flammable materials, and secure exhaust/flue pipes. The unit must not be operated without water in the heat exchanger.
Fuel System Maintenance:
- Removing Air Trap: A procedure is outlined to remove trapped air from the fuel line, which can cause ignition difficulties, especially after initial operation or refueling an empty tank.
- Fuel Guide: Emphasizes using clean, high-quality fuel (1-K Kerosene, No.1 or No.2 Fuel Oil, or ULSD) and proper storage practices to prevent contamination, which can lead to poor combustion and reduced unit life.
- Fuel Leaks (Regularly): Check for oil leaks from the unit and fuel feed line.
- Fuel Tank Water (Monthly): Remove any water or waste particles from the fuel tank.
- Fuel Strainer/Filter (Monthly): Clean the fuel strainer (Part #20476887) and fuel filter (Part #17185384) to prevent vibration, noise, ignition, and combustion failure.
Water System Maintenance:
- Water Leaks (Regularly): Check the heat exchanger for water leaks.
- Temperature and Pressure Relief Valve (Monthly): Pull up the lever to ensure the valve is operational and prevent immobility due to corrosion or mineral deposits.
Combustion System Maintenance:
- Flue Pipe (Monthly): Inspect for clogging, soot accumulation, corrosion, and leaks from pipe joints.
- Burner Inspection (Every Six Months): Check the burner and combustion area for soot and clean if found.
- Flame Sensor (Photo IC Diode) (Every Six Months): Clean the beam receiving surface of the flame sensor with a soft cloth to ensure proper operation.
- Blower Motor (Every Six Months): Ensure no dust on the blower motor fan.
- Heat Exchanger (Annually): Open the drain valve to drain the heat exchanger and pull up the lever of the temperature and pressure relief valve to allow air to enter.
Electrical Maintenance:
- Plug and Receptacle (Monthly): Ensure the plug is free of dust and fits securely.
General Maintenance:
- Flammable Materials (Regularly): Remove all flammable material from the area around the unit.
- Odor or Soot (Regularly): If soot is noticed at exhaust pipe fittings, consult a dealer for potential exhaust gas leaks.
- Dust (Monthly): Check for dust inside the unit and on the base.
- Gaskets and Washers (Every Six Months): Check for water leaks caused by improper sealing of water pipes and replace gaskets or sealant if leaks are found.

Safety Features

The unit incorporates several safety features:

Ignition Safety Device (Flame Sensor): Stops operation if ignition fails or flame fails during combustion, flashing Error code "6" or "7".
High Limit Thermistor: Stops operation if water in the heat exchanger reaches abnormally high temperatures, flashing Error code "1".
Power Failure Recovery System: Automatically reignites the unit after a power failure.
Fully Vented System: Provides outside air for combustion and vents all combustion products outdoors.
Fusible Link Valve: Stops fuel supply to the burner in case of a household fire causing extreme heat to the fuel line or water heater.
Fuel Strainer: Catches dirt and impurities in the fuel before it reaches the burner.
Heat Exchanger-Bi-Metal Switch: Extinguishes the burner if the heat exchanger temperature becomes abnormally hot due to a malfunctioning thermostat, flashing Error code "9".
Temperature Fuse: Blows and turns off the unit if air around the heat exchanger rises to an abnormal level, flashing Error code "4".
Air Pressure Switch: Deactivates and turns off the burner if the blower motor malfunctions or stops supplying air for combustion, flashing Error code "6" or "7".

Troubleshooting

The manual includes a detailed troubleshooting guide with error codes displayed on the Main circuit board (visible through an access cover window). These codes indicate specific malfunctions (e.g., thermistor malfunction, flame sensor malfunction, temperature fuse activated, ignition transformer malfunction, out of fuel, trapped air, clogged fuel strainer, air pressure switch issues, electrode discharge failure, heat exchanger bi-metal switch activated, not supplied water) and provide corresponding solutions, often recommending consulting a dealer.

WARNINGS throughout the manual emphasize risks such as fire, explosion, injury from moving parts, electrical shock, backfire, indoor air pollution, scalds, and burns. It is crucial to disconnect power and close the fuel valve before servicing and to never use gasoline or other volatile liquids as fuel. Repairs should only be performed by professionals.