20 Most Recent Bosch & Tankless LP Hot Water Heater - Page 2 Questions & Answers

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 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?

Sounds like you have a hydro-generator on this unit. Check the output on the hydro-generator it should be about 1.5V DC. If not clean the inlet screen and check your water pressure. Water pressure less than 30 PSI will cause issues. If you have 1.2V-1.5V DC make sure the power switch is on. If the power switch is on replace the control unit. I sell parts for Bosch units only!

I do not know how old this unit is or what model but many water heaters are not sophisticated enough to measure the temperature, but heat based on water flow and temperature rise. To start, tankless water heaters turn off every time you turn the hot water off. Lets use an example. You use the facilities, wash your hands then turned off the water and take a shower. You will bring the already heated water (from washing your hands) from the pipe up to the shower. Then the cold water that comes into the pipe from the reactivation of the water heater comes up the hot water pipe with warm then hot water just behind. If this is not your problem, keep reading. Every unit I have been called to see were installed wrong. Check your installation manual to see if the problem with the system started with the contractor. First, check the temperature of the water from the heater. If it is too hot and you are mixing too much cold water in, the unit will turn off because there is not enough water flow to keep it running. Second, turn off the valve at the water heater and turn on the hot water at a faucet. If the water does not stop running, there is a "plumbing cross over" usually caused by a failing pressure balance valve in a shower. Third, if the unit has not been serviced, go to bosch-climate.us to find a tankless water heating professional in your area. Totally Tankless LLC

C7 is a fan code, either blown fuse on the board, bad board, or bad fan. Fan needs 24VDC, if you get voltage to your fan and still have C7, the fan needs to be replaced. If no voltage to the fan, its either the fuse or the board.

whats the problem? Make sure you have rebuilt your watervalve(gets done every 3-5 years) if it doesnt get done, the unit will probably not light, or light intermittently, and you'll have wild temperature fluctuations

I'm assuming this is a 240FX. Sounds like a control board issue. Since this was such a rare machine, the board cost 3/4 the cost of a new unit, and was not something recommended to replace.

Sounds like the watervalve was never serviced. It will stick if its not serviced every 3-5 years according to the manual. If it sticks, it can keep your burners on after waterflow, and overheat the water still in the exchanger. This can cause plastic/pvc/pex to swell and burst. Thats why any machine says to have only metal lines connected for min of 3 feet. Since it got wet, you may have to replace your control box as well, but at least maintain your watervalve and recalibrate your microswitch. Those last 2 may be your only issues.

H2 wasnt an error code on those machines... could you check the display and ask again?

pilot fault not giving enough power to thermal couple or replace thermal couple