20 Most Recent Bosch AquaStar Indoor Natural Gas Tankless Water Heater with Vent Hood #125 - Page 8 Questions & Answers

try looking at this. might be a thermostat problem, usually a cheap fix and found on feebay. https://www.bosch-climate.us/files/201009031229480.635ES_English_11.2007.pdf

Not sure but check the inlet water at the heater, the filter may be clog up a little that restrict the flow. Did u use the heater at all during the winter? If not, the heat exchanger may be clogged with built up in there. U need to descale it. Good luck. Chinhcu

Sounds like the thermocouple is not holding and dropping the pilot out , so its could be the thermocouple or the valve it connects in to . But you can always contact bosch tech help line they are on line

It may well be a honey well which you can just change the motor . The top cover should come off 1 screw holding it and lift off you should see the motor there . Most plumbing and heating shops will stock replacement motors .

Sounds like a flow sensor may be bad. It may be registering flow when there is none and it sending signal to ignitor and gas solenoid that there is.

Hot water sensor defective

Error Codes and Troubleshooting Bosch Tankless

Check for water leaks on the system also check pressure relief it may be passing water .

Have you bled the rads of air

Contact the local distributor of the product for the exact information you need about installation. If you are on city water you should be fine.

Can someone please help me fine a link to a Bosch highflow 18e hot water system manual to set the temperature or send it to my email [email protected]

Attached is a link to the pdf format user manual. http://www.bosch-climate.com.au/files/201207160640570.Hydro%20V2.PDF

Before calling service technician, open following link for Bosch troubleshooting resources including parts, contact, possible manual, possible service bulletin covering replacement:
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

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Davey, look in your manual, I believe it may be auto pilot when unit is switched on. Check the attached links,instruction and guides, Good luck "I hope this helped you out, if so let me know by pressing the helpful button. Check out some of my other posts if you need more tips and info." Electronic Highflow http://www.bosch-climate.com.au/files/201208020158440.201207160720590.70R_UserManual1023V2_AU.pdf Bosch Installation Manuals

Could be one of three things first the dip tube on the cold side of your water heater could be broken off which would cause the cold water took to come out of the outlet side of the water heater to soon before being heated all the way which can be replced second your water heater could be full of sediment to the point where you're not getting the full amount of hot water so you would need a new water heater and third it could be a bad cartridge in Your Shower depending on the type of valve you have which could cause the water to mix. third one is least likely

before you condemn the tank, you may want someone to check the venting, if the condensate trap wasn't installed correctly, or at all then this could very well be the source of your moisture!