20 Most Recent Bosch PowerStar AE115 Tankless Water Heater... - Page 9 Questions & Answers

Clean your orfice...it sits at the bottom of your pilot burner, where the brass pilot tube screws in to. Its a small stamped piece of stainless, about the size of a pencil eraser. You can also buy new ones online for only a couple bucks

E2 is a cold water inlet temp sensor. Has your unit experienced any freezing conditions? If it senses below 36 degrees or above 90 degrees it will show this error. If its normal temp, and you still get this error...check your sensor. Its an 8(kohm) sensor. Make sure its not open. If it reads ok and your temp is not an issue, then you probably have a bad control board

Watervalve needs to be replaced....part number is 87070063440, and can be found online. Its only held in by the water connections and 2 Phillips head set screws(about 1 inch apart) directly underneath the junction of the plastic watervalve and the grey metal gas valve

Triac devices are not restive. They are like back to back SCRs. Once gated they will not turn off until the power crosses zero. It will do that 50 or 60 times a second then needed to be re-gated.

It may not be possible, you are at 122C which is just above the recommended max. In 1988, the Consumer Product Safety Commission recommended that water heater manufacturers preset the maximum temperature at 120 degrees Fahrenheit to prevent burns. Since several states have mandated this maximum temperature.

Does the unit have a flame sensor? Check manual. Flame sensors get corroded and need cleaned or replaced. I have had success cleaning them but when you can buy a new flame sensor

Ignoring the pressure drop which often is normal when the burner goes out, note that the pressure may also go up when burner is lit. After 1 min. - suggest the flame detector needs cleaning. It's situate in the combustion chamber, usually at the rear, and looks like a right angled 1 inch pin above the gas jets. Clean with 240 grit emery cloth and also clean the nearby gas jets with a tooth brush

Remove the pilot injector from old unit and fit into new unit

Call BOSCH 800-798-8161 tech support. If it is not too old even out of warranty they will help diagnose. You can get parts for free in warranty and buy parts at www.houseneeds.com out of warranty. from: http://www.fixya.com/tags/45_557701/water_heaters

call Bosh ------------They can tell you exactly