Bosch AquaStar Indoor Natural Gas Tankless Water Heater with Vent Hood #125 - Answered Questions & Fixed issues

Green can indicate a water leak .you would have to check for a leak to be sure

The problem is excessive down draft or condensation. Air flow is important in combustion appliances. Too much airflow down the chimney can blow the pilot out. This is readily apparent when it gets cold and there is air rushing down the chimney in the winter. There may be an air leak in the room with the water heater. While there should be a combustion air supply that is sufficient, there should not be a place for the air coming down the cold chimney to go. That would eliminate the draft. Another thing is if a furnace is in the same room and does not have enough air to supply the burners. IF it is an older furnace without a combustion exhaust fan or has its own flue, the air being drawn into the furnace burners may be blowing the pilot out. Last but not least is the condensation issue. When cold water enters the tank it can cause water to condensate on the outside and drip down into the burner and put the pilot out.

Slower the flow hotter the water is how it works . Sounds like the water section is blocked and could well need cleaning out . Draw back with this system is you need a good inlet flow and flow will drop when you open other taps . they are good for a small house a family house not that good . Not much you can do put in a bigger water inlet to heater ?

possible faulty pressure switch connected to the water line and that is failing to turn on the main gas tap solenoid best have it checked by an accredited gas fitter or service center for the make

http://www.bosch-climate.us/files/201109162028550.250SX_English.pdf

I would question the Thermo couple. It pretty much runs the whole show. Inexpensive quick fix. It's the small tubing that is connected to the gas valve. The other end is a bulb that sits over the pilot flame.. Remove the old and match it up at the hardware store. Install new coupler ensuring bulb is directly over the pilot flame Common iten. The thermocoupler alks to the gas valve. If the pilot flame extinguishes (goes out) the bulb cools and shuts down the gas valve so the pilot gas feed doesn't permit raw gas to accumulate, avoiding the need emergency Services. . You will not get the heater to fire until the bulb is good and hot. The red push button ,when depressed will allow the pilot flame to be lit. Hold it down until the heater fires, indicating the T-coupler has reached its operating temp.Good Luck-Ned

Hold in your pilot button, then push the spark button repeatedly to light your pilot. Once its lit, hold that pilot button in for 30 seconds to heat your thermocouple. once its heated, release the button, and slide the slider to burner position. Turn on hot water fixtures to get the unit to light

C7 code has to do with your main fan. Either its not working due to it being blocked or having gotten wet/damaged/power surged, or your control unit isn't supplying the correct 120V to the fan. Your control has a ceramic fuse that you can test as well. First, look for 120V to either the left or right pair of wires in the molex plug on the fan. if you have voltage, then the fan is bad. If you dont, its either just a fuse, the board is bad, or the fan is bad causing the fuse to blow. Insert the supplied spare fuse, and power up the unit. If it blows the fuse again, its the fan.

Bosch Aquastar 125B Water Heater Repair Parts Pre January 2003 Bosch Aquastar 125B Repair Parts Selection Grid This web site has Aquastar 125B parts. It appears your unit was manufactured 7/7/02, so that is what I pulled up for you. At least this will be a start for you to locate the part. I hope these links work. Bosch Aquastar 125B Water Heater Repair Parts Post February 2003

sounds like pressure relief valve is stuck closed free of or replace

Kathy, dont mess with it. get an engineer

Copy following links to help identify problem:http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.htmlhttp://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intelliventhttp://www.thetankatwaterheaterrescue.com/forums/forum3/Add a comment and describe product betterGenehhhhhh If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Turn off water:http://waterheatertimer.org/Emergency-steps-for-leaking-water-heater.htmlSave money and fire risk by installing regular tank type gas heater:http://waterheatertimer.org/How-to-install-gas-water-heater.htmlGeneh If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Yes. Tankless computers that heat water can be fire hazard.There is no combustible FV system on tankless, as you find mandated with ordinary tank-type heater. But same with your fireplace.If flammable vapors are drawn into tankless air intake or fireplace, the flame will ignite vapors and cause fire inside home.Always shut down tankless pilot light and burner when using WD40, lacquers, solvents, spray paint, gasoline, etc.Do not store flammables nearby.And do not store or use other chemicals nearby since trace amounts of many household chemicals such as bleach and pool cleaners, craft products, household cleaners, etc will enter burner and corrode parts inside tankless, severely shortening life of tankless burner and sensors.The internal parts on tankless are un-known fire hazard, because I have not read specific reports in news.However most companies today have absolutely locked down news stories that might affect their sales, so these incidents are no longer getting reported if they are happening. So if you voted republican or \'conservative\' in the elections, then you voted to protect companies rights to withhold vital safety issues from you until enough people get killed that someone says something without fear of losing a job. Because the rich need you to protect their right to fire you from your job so they can get more money from you. And somehow they got people to vote for this, under the guise of protecting your job. lolGene If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

is the water temperature dial turned up? or even functioning?

not freezing is it?

Unplug micro switch located on bottom of water heater if it has one

Copy following links to narrow down cause for EA error code:http://waterheatertimer.org/pdf/Bosch_EA_error_code_troubleshooting.pdfhttp://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

The following link has general troubleshoot steps for Bosch A2 errorhttp://waterheatertimer.org/pdf/Bosch_A2_error_code_troubleshooting.pdf If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

This is also known as a flame rectification sensor. It basically is what the computer board uses to detect if the pilot flame is lit. When it makes an attempt to fire is there any evidence of flame ignition? This error does not mean that the sensor is bad for sure. The error could be caused because the water heater is only making three attempts to fire and then shutting down. These water heaters are very complex and have many sensors,valves, ect that are all controlled by a computer board. Some of the basic things to check for are... Make sure that you have plenty of gas pressure. These units have a built-in pressure switch and will have issues if they are starved of gas. Most of these tankless water heaters are up to 400,000 btus and a half inch gas line or undersized connector won't work well. You can also check and make sure there is no pipe dope are debris stuck in the screen inside the gas line where it enters unit. Inspect the pilot assembly for debris or obstructions and try to blow out with compressed air. Also look for any loose electrical connectors on the board or to the sensors...one may have come loose.