Bosch & Tankless LP Hot Water Heater - Answered Questions & Fixed issues

If the thermocoupler is defective the gas to everything is shut off. The coupler is the bulb that sits ib the pilot flame If it doesn't heat up it will sense no pilot and shut the gas off. They don't cost much and are easy to change. Good Luck, Ned

It sounds like a bad flo switch. If not, then the problem is more likely in the mother board. Call Bosch back and ask for a supervisor right away. The peons sometimes are given advancement according to how many calls they handle, so they have a time crunch. Go right to the supervisor. Good luck!

Look for a water temp control on unit. Otherwise a lower temp can be attained by having a higher water flow to minimize temperature buildup in heating coil.

have a plumber check the installation as it appears that there is a temp control mixer in the kitchen line that should be in the bathroom line Many states and countries now have made it mandatory the full uncontrolled hot water cannot be used in a bath, shower, wash basin but has to limited to a max temp of 70 C to prevent burns to the skin

You either have a weak spark from your ignitor which needs replacing, a bad elec connection to the ignitor, or it needs to be repositioned nearer the burner. Check connections and try repositioning it before you install a new on.

Open following link for Bosch tankless troubleshooting resources, including Bosch contact information, typical manuals, error codes, tech support, parts, fuel-saver calculator, service bulletins, water heater forum, fixya links, disclaimers, and links for finding service technician.
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

Read manual cover to cover, make sure tankless receives yearly maintenance as outline in manual.

Add a comment with your experience so others with same-similar problem can benefit.

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The S 13 BP is a simple unit that does not have a pilot light. It uses electronic ignition on demand, which is what you hear clicking. If there is no gas going through and you've verified there is gas to the inlet, then it has to be the gas control valve.

http://www.ps2netdrivers.net/parts/bosch.gwh.425.hn/

Stupid me but could you be a little bit literate in asking a question.My dog write better questions that I can understand than this scribbling.A GWH 2400 is the little brother of the GWH 2700 much like the 635ES. If you have an LP model be sure to use the overpressure protection valve supplied by Bosch as overpressure in LP (above 10-14" WC) can completely destroy this unit.And you can use a TPR or PRV for 170,000+BTU being sure you get a House Pressure valve of 60-80-100 PSI+ and not the boiler PRV for 30 PSIBeyond that your questions above states nothing recognizable as a technical question

first time heard of a tankless that is round

http://waterheatertimer.org/pdf/Bosch_10P-water-wizard.pdf Gene If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

It's in the Bochum owners manual page 7

Check gas pressures first especially on low setting. Ensure gas burner is clean get unit serviced if over 2 years old. Check or replace water flow sensor & clean inlet filter.

Check or replace diaphragm in the water section also clean the filter fitted at the inlet

Define melts cold line.

the igniter probably did this prior to the adjustment if not check manuel if this not a safety back up to prevent gas from not being burned .

It sounds like there is too much pressure in the hot water pipes. You can try adjusting the pressure. Do it a little at a time to see how much hot water is coming out. The only other thing I can think of is that there is a large delay between the switch and the water flow. meaning you will need to stop the water a while before you actually want the water to stop flowing. Elisa Jed ' http://www.mccreeryhvac.com

need to know what you are resetting

Reset Button.....be nice if you gave us a brand/model to go with. If you mean the small GFCI inside the heater, you'll need to get a Tech Service Call and call Mfrs Tech Support as something is short to ground. This can't be done remotely as you have to track currents and voltages and resistances with a multimeter. Tankless usually draw less than 2A even when fully on so doubtful you're overloading a general house circuit. Might even be the small interior GFCI that's bad. That's why you need Tech Support.

Question is how am I to know what model this is? And as stated the question answers itself.....Plumber removed...did he reinstall? of course but as stated the issue is unanswerable. Does the Pilot light? or if this is an electronic unit than something in the feedback ignition sensor is amuck. Is this a 125VP, 125B, 125H. 38B or a 240FX, 250SX or 2400/2700 or newer?