20 Most Recent Bosch AquaStar 2400ES-NG - Page 8 Questions & Answers

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!

check that the flue fan is working and that the plastic air tubes from and to it are connected

People often think it is EO, but it is EC. Depending on the age and instalation, ithe may be a very simple repair. EC is a failure to ignite.

Can you get the manual online? You have the Manufacturer info so you probably have the model number too. I found a manual on Manuals.com for my boiler so they may have yours too which will hopefully have some information on filling boiler although I realize each installation is somewhat different but that's why it's difficult to answer you question. Usually there is a manual pressure valve that regulates the water pressure in the boiler which is usually pretty low...like less than 20 lbs. The manual should tell you the pressure as well. But this pressure valve has a flip handle that comes off the cold water line to the boiler to do just what you want to do...refill it with water. When refilling the boiler (if you find the valve, you may have to purge the air out of the lines which there is a whole other process for. But you shouldn't allow cold water into a hot boiler...it could crack it when the cold water hits the hot cast iron. So make sure the boiler is cool when filling it up. Now go try to find that manual!

Having problem finding one. Is there a model #? Also what are you trying to find out? as sometime googling the problem finds a solution faster than googling manual.

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Your electronic ignition unit is not rectifying through the gas flame, it is a sensitive piece of equipment and has failed.

I believe they are under the unit by the pump.