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. Contact a gas service person to clean the remove and clean the burners.
Mineral Scale Build-up: The AquaStars heater, when operated at lower temperatures settings, do not accumulate mineral build-up. If however, the water has a high mineral content, periodic descaling may be necessary. The heating coils should be flushed with a descaling solution. Consult your service person.
TROUBLE SHOOTING (see maintenance table)
Introduction
The AquaStar 125 B “S” 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.
Problems are stated in upper case, bold face. Most common causes for the problems follow in order of likelihood. The suggested solutions require that the cover be taken off. To do this, remove incandescent particle tray and unscrew the central screw located at the bottom of the front cover. Pull main cover out toward you and lift up and out.
PILOT LIGHT WILL NOT LIGHT
1. No gas to the AquaStar
A.Gas cock on gas line may not be open.
B.Gas valve button has not been pushed in on “PILOT” position ( 
).
C.Gas regulator may be shut or damaged.
2.In-line AquaStar gas regulator jammed (usually on LP gas)
Replace or unlock the regulator. Note: The regulator furnished with the heater is designed for low gas pressure. Excessive pressure will lock it up (propane only). Locking usually happens if the gas pressure between the gas tank (propane) and the water heater’s gas regulator has not been reduced. See page 2 for recommended correct gas pressure. To unlock a regulator, consult your gas supplier.
3.Pilot orifice clogged and/or air screen dirty, or pilot gas filter is dirty.
Clogging of the pilot burner can be caused by dust and any suspended matter contained in the ambient air.
Although the filters can lengthen the cleaning intervals, they can never completely prevent such clogging. In consequence the gas jet issuing from the pilot orifice is reduced and or the air mixture is reduced. The pilot flame is weak and thus can no longer heat the thermocouple sufficiently. For cleaning purposes, the air filter screen is pulled off, washed and blown out. The pilot orifice has likewise to be cleaned or exchanged. Consult a gas service person to clean the pilot.
4. 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. Because of the very small pilot orifice (especially on LP gas models), bleeding out all the air could take several minutes. Depress the pilot button ( 
) and depress this button until all the air has escaped, and the gas has arrived. During this process, press repeatedely on the piezo ignition button until the pilot flame has ignited.
PILOT LIGHTS BUT FLAME GOES OUT WHEN BUTTON IS RELEASED
1.Pilot push button was not pushed in far enough or was not held in long enough
Depress the pilot button. Hold it pushed in for at least 15 seconds to give time for the pilot flame to properly heat the tip of the thermocouple.
2.Pilot flame improperly aimed or is too weak so it is not properly heating the tip of the thermocouple.
The Pilot flame should be a sharp blue flame and aimed at the tip of the thermocouple so that it envelops 10 mm (3/8 “) of the thermocouple tip. Pilot flame has to be properly aimed at the thermocouple. See Fig 8.
3.Poor thermocouple connection at the electromagnet Note: Electromagnet is part #8707201094 located on the right side of the gas valve behind the piezo pushbutton assembly. Check the tightness of the thermocouple connection nut at the electromagnet: The Electro-magnet connection is a large aluminum 17mm hex head nut. The thermocouple end is a 5 mm brass nut which screws into the 17 mm nut. Tighten the thermocouple nut snugly but not too tight.
4.Poor circuit connections at the ECO. (Energy Cut- Off overheat protection)
Oxidation or looseness of the ECO terminal connections can result in millivolt current loss through the thermocouple safety circuit. Clean terminals with very fine sand paper or an eraser and reconnect ECO leads.
5. Faulty ECO (part #8707206017)
If cleaning the terminals attached to the ECO did not fix the problem, connect a jumper wire between the two wires and try to relight the pilot. If the pilot flame now remains on, replace the ECO. If the flame still goes out when the button is released, the ECO is not defective. Go to next step.
6.Faulty thermocouple (part #8747202083) or electromagnet) Unless these 2 parts are at least 8 to 10 years old, it is very unlikely that they are faulty. Before testing, reconfirm that #2 is absolutely correct, and that all connections are clean and tight.
