Question about Bosch & Tankless LP Hot Water Heater

1 Answer

AquaStar 125B NG continues heating water when no demand

My AquaStart 125B NG continues heating the water when all the hot water facets are turned off in my house. It is like the value gets stuck on. I do not have a circulating pump. I have to manually turn the switch off on the unit to stop it from heating the water to reset it.

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

I found the manufactures website and read this specific tech bulletin. I will be replacing or repairing my water value soon.

http://www.boschhotwater.com/Portals/7/TechBulletins/TWH-G1-25_Water_valve_rebuild_B.pdf

The bulletin said the following:
If the burners fail to go off immediately when the
water is turned off, usually due to mineralization in
the water valve on older heaters. To test for this
possiblilty, run hot water at a faucet, then shut off
the cold inlet supply and observe if the burners go
off immediately. If they do not the Aquastar will
overheat and shut down on safety depending on
the delay.

Posted on Jan 12, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

On demand hot water heater gets cold for a short while during showers.


Check for crossover.
Bad single-handle faucet cartridge causes cold water to enter hot pipe, so hot never arrives and tankless does not run consistAntly
http://waterheatertimer.org/Crossover.html

Apr 13, 2013 | Bosch AquaStar 2400ES-NG

1 Answer

Bosch aquastar wont get hot


1) If tankless is not showing error code, the problem might be single-handled faucet cartridge:
http://waterheatertimer.org/Crossover.html
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

2) Catch up on maintenance, such as cleaning combustion parts, have gas pressure checked, etc.

Feb 20, 2013 | Bosch AquaStar Natural Gas Tankless Water...

1 Answer

Bosch 125b-ng water heather has low flame only


Did you check to make sure the shut off handle is on the on position?

Dec 19, 2012 | Bosch AquaStar Natural Gas Tankless Water...

1 Answer

Hi there, I have a bosch aquastar 125b waterless tank. My problem is that i am not getting hot water at all. The water runs during the shower and it stays warm. HELP!!


This should run two showers at once with no problem. If you have a shut off valve on the cold side of the heater, try closing about halfway. This will slow the water flow and the water will have more time to heat up as it pases through the tank. If you dont have a shut off valve, just cut back the hot water valve on your shower and do not use any cold water. If it gets too hot then turn on a little cold water. The object is to slow the speed of the water going through the tank. Tankless heater take a little getting use to but they work great when you know how to treat them. On my shower I turn the hot all the way on until it gets hot and then add a little cold water to bring the temp down. You may have too much water going through too fast to be able to heat it up to what you need. Try this and see how it works.

Mar 26, 2011 | Bosch AquaStar 2400ES-NG

1 Answer

I have a aqua star 125 bng-l ser 9650617 the only way i can get water hot is by turning on the shower annd the bathroom tap on?


These type of heaters require a minimum amount of water flow. If your showerhead is the most common flow-restricting type then perhaps it is not permitting the minimum amout of gallons per minute to flow through the unit for it to remain engaged. You might have to try removing the flow restrictor :(

Feb 04, 2011 | Bosch AquaStar Natural Gas Tankless Water...

1 Answer

Aquastar 125b ng: after 2 years of use water is not hot enough


Sounds like hard water. Service the water valve. Parts are available from your local Bosch Service Provider (Contact Bosch if you don't know who the service provider is).

Feb 03, 2010 | Bosch AquaStar 125FXKIT-NG 125FX Natural...

2 Answers

Bosch AquaStar 125b ng suddenly goes cold during shower


Does it happen to any other fixture? If not, it's most likely your shower valve and not heater.

Sep 01, 2009 | Bosch AquaStar 2400ES-NG

1 Answer

No hot water


Aquastar 1600H NG Natural Gas Tankless Water Heater Bosch AquaStar Model 1600H NG Natural Gas Whole house tankless gas water heater, 117,000 Btu input, natural draft with hydro-generated ignition. Provides endless hot water for one major application at a time . Can replace 40-gallon storage tank water heater. Optional Accessory: Model AQ1- Power vent with built-in... More freeze protection when venting horizontally. Capacity: 1 to 2 Bathrooms Dimensions: 8.75D x 18.25 W x 29.75H Weight: 40 Max GPM @ 45F Rise: 4.2 Energy Factor: NG .80 LP .84 Minimum Input: 28,000 Maximum Input: 117,000 Vent Size: 5 Gas Connection: 3/4 Water Connections: 1/2 Warranty: 12-year warranty on heat exchanger, 2-year on parts Features: Endless hot water Can save up to 50% off utility costs annually Perfect for one major application at a time No standing pilot, hydro generated

Mar 01, 2009 | Bosch 1600H-NG Natural Gas AquaStar...

2 Answers

Bosch aquastar 125b ng


Replace the thermocouple.

Thats the flame sensor.

If the gas valve is not sensing flame it will not stay lit.

T-couple's are about 9 bucks.

Nov 06, 2008 | Bosch AquaStar 2400ES-NG

Not finding what you are looking for?
Bosch & Tankless LP Hot Water Heater  Logo

230 people viewed this question

Ask a Question

Usually answered in minutes!

Top Bosch Water Heaters Experts

Colin Stickland
Colin Stickland

Level 3 Expert

22082 Answers

Donni Steen

Level 3 Expert

659 Answers

john h

Level 3 Expert

10036 Answers

Are you a Bosch Water Heater Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...