Bosch Aquastar 2400E LP Does Not Heat Water

Call a qualified service tech immediately.
Gas explosion indicates dirty combustion parts, and gas is not fully igniting when tankless turns on the gas. So gas builds up and then explodes causing serious damage to tankless, and serious risk to homeowner.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Before calling service technician, open following links for Bosch troubleshooting resources:
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html
Resources at Bosch
http://www.boschhotwater.com/HelpfulResources/TechnicalSupport/BoschAquaStarModels/tabid/370/Default.aspx
Typical Bosch Aquastar manual:
http://waterheatertimer.org/pdf/Bosch-aquastar-170vp-manual.pdf

All tankless and tank-type gas water heaters require regular cleaning and maintenance.
It is unknown if your unit needs maintenance or repair parts, but catching up on maintenance using information from manual is good place to start.
Gas appliances are increasingly complicated and experienced technician is good resource to have in local area before installing tankless.

See the distributor ,they should be able to supply the required regulator.
I have an earlier model Bosch tankless water heater. my instruction says mine can.
I would assume that yours should be also.
Good Luck.

http://www.tankless-water-heaters.com/troubleshooting.htm

remove from the wall.... donate to charity and purchase a quality tankless water heater!!!

Rinnai, Takagi, Noritz are the only brands I will install. I refuse to even work on Bosch "Aquastar", complete garbage!

I have an AquaStar tankless and it has started making that high pitched sound when in use. I wonder if that means I have clean the heat exchanger. I called Bosch but they won't help since it is installed in a bathroom--in violation.

The 250 MUST have the condensate line connected. EC comes from gas supply problems and CO2 levels not being adjusted. LP units require 3/4" smooth gas pipe or 1" corrugated pipe minimum size. The LP regulator needs to be turned up to about 13 inches of water column and with all the gas appliances on, measure no less than 11 inches of water column. The CO2 levels must be measured by a qualified gas technician with a calibrated (with in 6 months) CO2 analyzer.

This is a great heater. It is however crucial that it be installed to every detail of the manual. If there is trouble send pictures to Bosch tankless you can call 1-800-283-3787 ask for Bosch Tech support or go to boschhotwater.com click find a contractor and call the closest Bosch Service Provider most will travel.

Aquastar 1600H NG Natural Gas Tankless Water Heater Bosch AquaStar Model 1600H NG Natural Gas Whole house tankless gas water heater, 117,000 Btu input, natural draft with hydro-generated ignition. Provides endless hot water for one major application at a time . Can replace 40-gallon storage tank water heater. Optional Accessory: Model AQ1- Power vent with built-in... More freeze protection when venting horizontally. Capacity: 1 to 2 Bathrooms Dimensions: 8.75D x 18.25 W x 29.75H Weight: 40 Max GPM @ 45F Rise: 4.2 Energy Factor: NG .80 LP .84 Minimum Input: 28,000 Maximum Input: 117,000 Vent Size: 5 Gas Connection: 3/4 Water Connections: 1/2 Warranty: 12-year warranty on heat exchanger, 2-year on parts Features: Endless hot water Can save up to 50% off utility costs annually Perfect for one major application at a time No standing pilot, hydro generated

did you check to see if your temp regulater is working properly? also you have a thermocoupler that senses the heat of the water and works in conjunction with the regulator. have either one or both replaced and the problem will be solved. please rate this thanks