Top 20 Bosch PowerStar AE125 AE125 Whole House Electric Tankless Water Heater... Questions & Answers

It should be producing hot water at the temp it was set at such as 120-140 degrees. If it is exceeding this one of the safety devices maybe disconnecting it. Thermal control might need some servicing. See what temp it's set at then put a thermometer on a near water outlet to see what's going on. Good luck.

http://waterheatertimer.org/pdf/Bosch-AE115-AE125_manual.pdf Bottom page 10 troubleshoot Add tempering tank to pre-heat cold incoming water http://waterheatertimer.org/Tempering-tank.html Call service technician Delime heat exchanger. http://waterheatertimer.org/How-to-delime-tankless-water-heater.html Replace with tank type? http://waterheatertimer.org/How-to-install-electric-water-heater.html Gene If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Replace heater? Do not install tankless. Call for service? Manual does not show troubleshoot or repairs Bosch site does not show the AE125 series water heater any longer http://waterheatertimer.org/pdf/Bosch-AE115-AE125_manual.pdf Gene If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Hey Andy. Do you have your owners manual? There should be a section near the back that will break down the diagnostic code the flashing light is giving you. If not remove the front cover and look inside should be a wiring diagram and light legend.

I just tried to replace one of the o-rings on an AE125. The old original one came out distorted do to the fact that there's no groove to hold the o-ring in a uniform position. Even though I was careful and evenly tightened the cap screws, the new o-ring started leaking an hour after I had left the job. My opinion is the mounting of the metal lid to the plastic tank is a bad design. Good luck on your repairs.

Flashing light means bad control unit..or your flow is too low. If you have a couple fixtures on, and its still blinking, the board needs to be replaced.

Light flashing while water is flowing means you have a bad control board. Needs to be replaced. They can be purchased online

there are no valves in the unit. You can only regulate waterflow through this machine with self-supplied ball/gate valves

Turn circuit breakers fully off and then back on.Use nose to smell for burning inside main panel.Make sure you are getting 240Volt and not just 120V from one leg of the breaker.Do stress test on breaker panel.http://waterheatertimer.org/Troubleshoot-household-electricity.html#stressLeast expensive solution: Replace tankless computer for $285 buying tank-type electric water heater from local box store.If tankless computer is new, then call installer.If you installed it yourself, call professional installer.http://waterheatertimer.org/How-to-wire-Tankless-electric-water-heater.htmlGeneh If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Turn of leave for 2 minits then try again

Do you have 3-phase water heater? Is this balanced or unbalanced 3-phase unit. Add comment and describe product in detail, including brand since i have some service resources for both types.Or do you have ordinary residential split-phase 240Volt Bosch tankless computer that heats water, and has 2 or 3 separate elements, and a separate circuit breaker supplying power to each element? And testing across both hot leads coming from each breaker yields 238Volt?Copy following link for Bosch tankless manuals, with brief troubleshoot section that does not provide detailed service procedures for repairing tankless computer:http://waterheatertimer.org/How-to-wire-Tankless-electric-water-heater.html#manualIf this is new water heater, then call installer. If you installed yourself, then remove tankless and return to seller for refund.Tankless computers require certain amount of water flow to activate computer sensors. Turn on Hot tap and listen to pipe to hear if water if flowing through hot pipe. Check for crossover:http://waterheatertimer.org/Crossover.htmlClean water filter usually located just above where cold water connects to unit.Delime tankless ... and use water softener. Tankless cannot be exposed to more than 11 grains hardness in water, or parts will fail within 2-3 years. Simply deliming tankless heat exchanger each year will not maintain full efficiency... although for typical family of 4, tankless comper water heater costs $100 more to operate than tank-type heater according to manufacturer's promo literature and independent studies.Call local technician who specializes in fixing tankless computers. For plumbing problems call local plumber. These are two different things.If tankless computer is older, then cut losses, and buy tank-type electric water heater at Lowes for $285 and make quick changeover and have hot water same day. Sell old tankless on ebay and cheat next guy, or sell at scrapyard for $3 per 100.Geneh If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Control unit or flow transducer. If the transducer(impeller in the clear tube) is spinning freely with waterflow, then the circuit board needs to be replaced.

You need three #8 wires for AE125. Two #8 wires for AE115.1) Copy following link for wiring information:http://waterheatertimer.org/How-to-wire-Tankless-electric-water-heater.html2) The AE125 has 3 elements, and requires 3 wires.Each wire is sized #8 copper, and is connected to 40 amp breaker, up to 100 feet. Over 100 feet, use 50 amp breaker and #6 wire. Oversizing breaker and wire is smarted and more efficient than undersizing.3) Often a separate subpanel is installed to provide 3 extra spaces.http://waterheatertimer.org/images/Main-subpanel-Tankless-600.jpg4) Makes sure main breaker panel can accept additional 120 amps of draw without overampping panel ... and starving other appliances of full power.... that will damage appliances, overheat motors, and damage main panel and overheat main breaker. You want to oversize, not undersize electric service when installing tankless electric, which is why I do not recommend tankless electric installation, including issues of costing more to operate, and expensive repairs, and general money risk-nuisance of owning tankless vrs tank-type heater.http://waterheatertimer.org/Troubleshoot-household-electricity.html#stress If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Product manual shows electro-mechanical thermal cutout page 9 but offers no troubleshoot steps except to say that overheating is cause.http://waterheatertimer.org/pdf/Bosch-AE115-AE125_manual.pdfhttp://www.bosch-climate.us/files/201009211859150.EP-23_Removing_and_replacing_element_assembly.pdfTest elements:Remove both wires off element.Set multimeter to read ohms.Watt and volt rating appear on side of each element.Ohm = Volts squared divided by wattage.For example:Assume 240Volt circuit (240 Volts squared = 57600) Assume 9000 watt element > check side of element for rating.So 57600 divided by 9000 watt element = 6.4 ohmshttp://waterheatertimer.org/images/ohm-reading-for-emements.jpgHave you de-limed this unit?Is there a check valve causing closed system in the plumbing, that might also cause decreased water flow?Are there reduced-flow faucets or clogged aerators?What happens when suspect cut-out element is no longer connected? The unit should continue heating. If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Question posted under Bosch tankless.Question says 'tank'Brand, model, and type heater unknown.Elements mean electric.'Thermal cutout pops when taking shower produces cold water' indicates tankless, since tank-type would maintain some hot water.No error code might indicate tank-type.Add a comment with type, brand and model number of heater for possible assistance. If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Contact Bosch 800-283-3787, or service technician.http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.htmlProduct has 10 year limited warranty against defects in workmanship, failed parts, failed heat exchanger for original homeowner with receipt. But does not cover neglect, failure to follow maintenance, installation etc. Pg 23 example manualYou generally have to pay for service call to verify installation, then send tankless into factory, or have service technician repair unit, at your expense minus cost of partshttp://waterheatertimer.org/pdf/Bosch-AE115-AE125_manual.pdfTo double check wiring:http://waterheatertimer.org/How-to-wire-Tankless-electric-water-heater.html If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Heating water can peculate chemicals out of water, such as metals and organics. Especially above 138 degrees.Have well water tested.Turn down thermostat temperature.Or reasonably harmless well-water bacteria can react with anode rod, or other reaction in softener, to produce colored water, and smells.Different water can produce different sludges, brown, red, gray, black, yellow.The sludge can also combine with deteriorating pipe flakes to clog water flow.Sludge can accumulate over years in low spots in pipes, or at elbows and constrictions.Have plumber flush pipes.Or run new pipes.Also delime tankless yearly, and flush with white vinegar as shown in product manual, and treat bacteria with H2O2 hydrogen peroxide.http://waterheatertimer.org/pdf/Bosch_Descaling-heat-exchanger.pdf If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

If you smell it - look fer it. It may be a bad connection on the AC supply line all the way back to the service panel or inside the heater connection panel. Bad connections cause high heat and discoloration of wires or connectors and a serious voltage drop to the appliance.

What happened to the screws from the old terminal strip?If it is a different size you need to drill new small holes in the box (not the tank or pipes) and attach it with self tapping screws. Make sure each wire of the unit matches the same wire being connected as the original connections.

There are a lot of other things that eat electricity. Like space heater and using ovens for heat. Heat pump.Central heat fan running all the time. House lights left on. Outside flood lights. Clothes washer using HOT water. Look around real good. It all adds up. Also the power co. may be charging more for "fuel" costs surcharges. Here in GA I'm paying a bit more now to pay for a nuclear power plant.