Bosch Appliances 125FX NG, 125FX LP specifications Pilot Sparks Continuously with no Water Running

Mineral deposits can eventually (3-5 years in hard water areas) corrode the water valve parts to a point where they will need replacing. Any sign of moisture at the bleed hole is a sign that the water valve needs to be replaced immediately.

10. Loose connection at the ECO

Ignition sparker will not operate if the electrical circuit is interrupted. Check that the connections to the ECO are secure and tighten if necessary.

11. Reset electrical power to heater

If resetting the electrical power corrected the symptom then likely the unit’s Safety Spill switch (Flue gas safety device

-#9 on page 19) had tripped from a flue blockage during the previous usage. Inadequate combustion air to the room area can also cause the unit to improperly vent. Improper venting or insufficient combustion air must be corrected. Consult a licensed professional to inspect the installation.

SPARKS APPEAR AT PILOT WHEN HOT WATER TAP IS TURNED ON, BUT PILOT AND BURNERS WILL NOT IGNITE

1. Air in the Gas Line

Note: Normally this is a problem only at the time of initial installation, after the pipes have been worked on, or after a propane tank has been allowed to empty, or after the heater has been shut down for a long time.

Bleed all the air trapped in the gas line by turning the hot water faucet on and off until the air has been cleared from the line.

2. No gas to the AquaStar

A. Gas cock on gas line may not be open

B. Gas regulator may be shut or damaged. Replace or unlock the regulator. Note: The regulator furnished with the heater is exclusively designed for low gas pressure (less than ½ psig). Excessive pressure will lock it up. Locking usually happens when the gas pressure between the gas tank and the water heater’s gas regulator has not been properly regulated. See Page 2 for recommended correct gas pressure. To unlock a regulator, consult your gas supplier or call CEC.

3. Pilot orifice clogged or gas valve is dirty

Clogging of the pilot burner can be caused by dust in the air or dirt in the gas. The pilot orifice or gas filter may need to be cleaned or replaced. See Fig. 14.

4. Water valve assembly needs to be checked

If the pilot orifice is clean, the water valve assembly should be checked. The adjustment screw on the water valve micro- switch may not be tight enough (fig. 15). Remove central cap beneath micro-switch assembly, carefully loosen the adjustment screw until the pilot light ignites. At that point retighten the screw one and a half turns. See Fig 15.

5.Pilot electrovalve switch may need to be replaced (See Fig 10).

Call CEC.

6.Electronic Control Box may need to be replaced (See Fig 10).

Call CEC.

PILOT SPARKS CONTINUOUSLY WITH NO WATER RUNNING

1. Microswitch needs adjustment

If no water is running, but pilot electrode continuously sparks, the microswitch screw to the water valve needs adjustment. See Figure 15.

PILOT LIGHTS BUT BURNERS WILL NOT COME ON

1.Confirm the flame sensor is in its proper position. (see Fig. 13).

2.Sensors for exhaust gases may be loose.

The burners will not come on if the powered fan exhaust is not working. Check that the unit is plugged in and that the sensors for the flue gases are secure.

3.Confirm the ECO connections are secure.

4.The Electronic Control Box (Fig 10) may need to be replaced.

5.Burner electrovalve switch may need to be replaced (see Fig. 10).

MAIN BURNERS GO OUT DURING HOT WATER USE

1. Deficient exhaustion of flue gases

Check that vent is correct and clear of any obstructions, that sensors for flue gases are secure and that electrical connection has been made. If the heater will not come back on, it will be necessary to turn the electrical supply to the heater off and then on again.

2. Flow rate diminished below activation rate

Be certain that water flow is not less than required amount to activate heater.

3. Unbalanced pressure in waterlines

The added restriction caused by the Aquastar in the hot water system can result in uneven pressures between the cold and the hot. In such cases when mixing cold water at the tap, the lower hot water pressure may be overpowered by a much higher cold water pressure, which may cause the Aquastar burners to shut down (deactivate). Make sure faucet aerators or shower heads are free of minerals.

Do not add any flow restrictor to the shower head. Typically this deactivation symptom is a result of the hot water being too hot to use comfortably. Warm inlet water generally causes this. Lowering the control knob setting and/or reducing the inlet gas supply to the heater should correct this deactivation symptom.

4.ECO (overheat sensor) tripped due to overheating Do not feed preheated water to this water heater.

5.Minimum inlet pressure on well pressure tank is inadequate

Check the inlet water pressure. On a private well, raise the minimum pressure setting to 30 psi. Confirm that the pressure tank is not water logged.

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