Question about Bosch AquaStar Indoor Natural Gas Tankless Water Heater with Vent Hood #125

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Bosch sx250ng tankess water heater

I have same problem , bosch said 300.00 dollar to replace control panel my unit has been doing this sinces installation over 4yrs. If you call bosch be prepaired to be put on hold a long.......long.... time.

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A2 error code.

Posted on Jan 04, 2010

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1/ check overheat stat 2/ check fan esp the little flexie hose rear fan area for pinhole 3/check diaphrapm valve 4/ check micro switch best of luck

Posted on Oct 31, 2009


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1 Answer

Error code 12

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.

Nov 02, 2013 | Bosch & Tankless LP Hot Water Heater

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I have a PowerStar tankless electric water heater, model #44-557710 and it was replaced about 3 months ago. This morning I had hot water and this afternoon I do not. When I call for hot water a red light...

Call Bosch. And exercise your 10 year parts warranty rights.
Copy following link for Bosch power star manuals:
Check circuit breakers, fully off and then fully back on. Test if voltage is at least 80% rating plate on unit. Check that temperature dial is set correctly. Call for service again.
Don't install tankless computer that heats water. You cannot fix this computer yourself, and they are problematic for owners.
Go to Lowes right now, spend $285 and buy tank-type electric water heater, roll it into your house, and save money, since the electric tankless computer heater costs average $100 more per year to operate than tank-type heater for average family of 4.
Tank type heater can be repaired by homeowner same day for $25 using off-the-shelf parts from hardware store. And that empowers the regular guy, and gets you off the junk tankless treadmill.

Aug 03, 2013 | Powerstar Water Heaters

2 Answers

A2 code appears and there is no hot water in the house. what should i do?

Problem with overheat cutoff. Press reset button on the control panel.
Before calling service technician, open following link for Bosch troubleshoot resources.
Recommend that people not install tankless water heaters, or heaters they cannot repair themselves since all costs are energy.

Aug 04, 2012 | Bosch Water Heaters

1 Answer

Water temp flucuates from hot to cold, esspedially on very rainy days.

Gas water heater problem based on weather could imply atmospheric interference, which might indicate venting problem. Check vent specs for that model. Make sure roof or side wall vent are installed correctly, and lenghts do not exceed maximum.
Problem might also be associated with elevation setting, since water heaters are sold to match expected conditions at that elevation.
If rain is associated with cooler temperatures, and more gas appliances run at same time, then unit might be starved for gas or home does not have enough ventilation.
Problem could also indicate that tankless unit needs to catch up on yearly maintenance, including clean burner and combustion parts, check loose wiring, test ignition system, clean air intake, bleed gas line, check gas pressure and check for correct vent, etc.
Before calling service technician, open following link for Bosch troubleshooting resources including Bosch contact, typical manuals, etc.

Aug 09, 2011 | Bosch GWH 425 EF L Water Heater

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Hi my Bosch 18 e highflow instantaneous hot water service, turns water cold after a minute or so then stays cold. When you turn the water off the pressure valve keeps pulsating for about 5 seconds. The...

Open following link for Bosch troubleshooting resources, including contact phone numbers and possible manuals.

If the conversion was made 3 years ago without a problem since, it might not be a factor.

May 05, 2011 | Water Heaters

2 Answers

Bosch 22e ys2439r fault 14 , (pcb 1 long flash and 4 short flashes ) cannot get unit to work , i've tryied replacing the pcb,gas valve w. solinoids ,thermistors...etc the fan will kick in for a second but...

No I cannot help fix your tankless.
There are just too many things that affect the operation to offer clear solution.
Before calling service technician, open following link for Bosch troubleshooting resources, including contact information for Bosch.

Repair most tankless water heater problems yourself, same day, any brand, for $320

Add a comment for more free help, and to share your tankless solution.

Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

May 02, 2011 | Bosch Water Heaters

1 Answer

250 sxo out door model water got in to control unit I need new control unit do you have replacement and how much is it

Less than 3yrs old? contact Bosch Gas Products Technical Support: 800-642-3111.



Dec 02, 2009 | Bosch AquaStar 2400ES-NG

2 Answers

Our second unit just failed and needs a new controller more money

The only Bosch tankless I have ever touched have been the 3 I have taken out and replaced with Rinnai. I think Bosch/Paloma/etc. have two problems:

1. They do not properly certify technicians before allowing them to install these units.

2. Their product is mediocre at best.

The biggest problem I've seen is that people don't vent them properly. The last one I pulled out had a combined vent length of 55'. 55 FEET! Absurd!
The units was condensing so much inside the vent that it washed out 2 gas control valves in ONE YEAR.

Buy Rinnai, buy Takagi, buy Noritz....maybe even a Navien (new player...time will tell)
Factory certified technicians, preferably equipped to do the gas & plumbing without having to sub it out.
Years of trouble-free hot water.

Good Luck.

Jun 30, 2009 | Bosch PowerStar AE125 AE125 Whole House...

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