Maintenance and Service, Trouble Shooting

MAINTENANCE AND SERVICE

REVIEW MAINTENANCE TABLE ON THE BACK OF THIS MANUAL.

Approximately once a year, the 125 HX should be checked and cleaned. To remove the front cover, first remove the incandescent particle tray, then pull off the temperature adjustment knob and unscrew and remove the plastic collar. Pull main cover out toward you and lift up and out. THE FOLLOWING OPERATIONS SHOULD BE PERFORMED BY A QUALIFIED SERVICE PERSON:

Vent System: Should be checked annually. Clean and repair as needed.

Water Valve (Part # 8707002649): The water valve on this heater should be serviced periodically. Lubricate component 36 on page 18 with a small amount of silicon, faucet or lithium grease every two years to keep its o rings fresh and pushrod sliding smoothly. Every 3-5 years replace component 36 on page 18. The frequency will depend on the mineral content of the water and conditions of use or whenever signs of corrosion appear at the gas and water valve joint. Periodically check that the water inlet filter (#27 on page

18)is clean as well. NOTE: If water valve is removed, be sure to also inspect the o ring seal on the end of the right hand side water pipe before re-installing. Lubricating the o ring with lithium or faucet and valve grease is recommended.

Pilot Flame: The pilot flame should burn with a clean, sharp, blue flame and should resemble the diagram in Fig. 10. If the flame is soft and yellow, the pilot burner orifice may need to be cleaned or replaced. The pilot flame should be approximately 2 inches long, extending past the flame sensor. If the flame is too small, it will not reach the flame sensor and the burners will not come on.

3mm

Correct gap between pilot burner tip and electrode tip

Piezo Electrode

Flame sensor

Piezo

Fig. 10 - Characteristic Pilot Flame

(Pilot assembly shown without pilot hood)

To clean the pilot burner and/ or the pilot orifice : Turn off the gas to the unit. Set the On/Off switch to Off (position ). Remove the cover of the heater. To do so, pull off the temperature adjustment knob and unscrew and remove the plastic collar. Pull main cover out toward you and lift up and out. The pilot orifice should be cleaned or replaced. Do

not enlarge the orifice.

Do not use any wire or sharp object to clean orifices. Natural gas orifices are large enough that you can usually clean them by blowing through them. LP orifices, on the other hand, are too small to clean and should be replaced.

To access the pilot orifice, remove 2 screws holding pilot assembly in place. Then loosen compression fittings to expose pilot orifice.

PILOT ORIFICE

Fig. 11 - Pilot burner with pilot orifice (Pilot assembly shown without pilot hood)

Main Burner Flames: The main burner flames should be blue, with a more intense blue cone in the center core. Yellow flames could be a sign of wrong size gas orifices or dirty burners, or a blockage on the heat exchangers fins. If some burners have yellow flames while others have good flames, it is likely that dust, lint or spider webs have partially clogged the burner venturis. To clean the burners, contact a gas service person.

Mineral Scale Build-up: The 125 HX heater, when operated at lower temperature settings, does not accumulate mineral build-up. If however, the heater is used at the higher temperature settings and the water has a high mineral content, periodic descaling may be necessary. The heating coils should be flushed with a descaling solution. The descaling is done only to the heat exchanger. The chemicals will damage the hydro-generator and other parts. Consult your service person.

TROUBLE SHOOTING

Introduction

The AquaStar 125 HX burners are activated by a water flow valve. Numerous water related problems can cause this water valve to malfunction such as: Insufficient water flow volume to activate the burners at its minimum flow requirement; Dirt in the water flow valve causing it to malfunction; Sediment build-up in faucet aerators, or shower heads; Uneven pressures between cold and hot. (with single lever faucets) Plumbing cross overs. These water flow related problems can cause the heater to deliver less than its full output, or to fail to ignite or to shut down completely.

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125HX LP, 125HX NG specifications

The AquaStar 125HX NG and 125HX LP are highly efficient gas tankless water heaters designed to meet the demands of modern households. With their compact size and advanced technology, these units provide an endless supply of hot water while maintaining energy efficiency. Both models cater to natural gas and propane applications, making them versatile options for various installations.

One of the standout features of the AquaStar 125HX series is its ability to deliver a powerful output of up to 199,000 BTUs, ensuring that multiple hot water outlets can operate simultaneously without a drop in temperature. Users can enjoy the convenience of hot showers, laundry, and dishwashing all at once, making it an ideal choice for busy families or households with high hot water needs.

These models incorporate a sophisticated modulating gas valve that adjusts the gas flow based on the demand for hot water. This technology not only optimizes energy consumption but also contributes to extended unit life by minimizing wear and tear on the components. The AquaStar 125HX units also come equipped with a patented electronic ignition system, which eliminates the need for a standing pilot light and reduces gas consumption.

Furthermore, the AquaStar 125HX NG and 125HX LP feature a durable heat exchanger constructed from high-grade copper, which enhances thermal efficiency and prevents corrosion. This ensures a longer lifespan and increased reliability for homeowners. Additionally, the units are compact and wall-mounted, allowing for flexible installation in various spaces, including tight utility closets or outside walls.

Safety is also a top priority, with built-in overheat protection and a freeze protection feature that ensures the unit remains operational even in colder climates. The AquaStar 125HX series operates quietly, allowing users to enjoy the benefits of hot water without the disruptive noise commonly associated with traditional water heaters.

In summary, the AquaStar 125HX NG and 125HX LP are leading choices in the tankless water heater market, combining efficiency, reliability, and innovation. Their impressive output, advanced technologies, and compact design make them suitable for modern living, ensuring homeowners have access to hot water whenever they need it. With these features, AquaStar continues to set a high standard in water heating solutions.

AquaStar 125HX NG, 125HX LP Maintenance and Service, Trouble Shooting, Not enlarge the orifice

Models: 125HX LP 125HX NG