20 Most Recent Bosch AquaStar 125FXKIT-LP 125FX Liquid Propane Gas Tankless Water Heater w/ Hood Questions & Answers

Consult manufacturer.

I know from you info that you don't want to work on it any more but this will help if you decide to try again.

Troubleshoot
Q. No Spark At Pilot? Q. Spark Appears When Hot Water Is Turned On, But Pilot And Burners Will Not Ignite? Q. Pilot Sparks Continuously With No Water Running? Q. Pilot Lights But Burners Will Not Come On? Q. Main Burners Go Out During Hot Water Use? Q. Hot Water Temperature Fluctuates At Tap? Q. Water Is Too Hot? Q. Water Is Not Hot Enough? Q. Burners Do Not Burn Cleanly; Yellow Flames When Operating? Q. Burners ignite without water flow? Q. Low hot water pressure? Q. Noise when the heater is running?

remove from the wall.... donate to charity and purchase a quality tankless water heater!!!

Rinnai, Takagi, Noritz are the only brands I will install. I refuse to even work on Bosch "Aquastar", complete garbage!

Before calling service tech, open following links for Bosch troubleshoot resources including phone support, error codes, possible manual.
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

No error code can mean PC board failure, or plumbing problem
http://waterheatertimer.org/pdf/No-Error-Code.pdf

There is likely an onboard relay stuck in the open position.

This is a gas appliance and should be serviced by an authorized BOSCH repair center to avoid potential catastrophe.


Thanks!!
2

Likely causes are low water pressure, dirty inlet filter, dirty screen on faucet. If this does not correct the issue, contact Bosch for instructions on adjusting the micro-switch. You will need a very small screwdriver when you call.

Hello,
I understand totally where you are coming from and honestly you have done good to get three years out of it. I installed a couple of the Bosch units and the stopped because of just the issue that you have. The gas valve and pilot combo in those units is junk. Even the distributor that I use has switched to the Noritz tankless water heater because of issues with the Bosch.
There probably is dirt in the pilot orfice that is very difficult to fix. Cleaning is very difficult and does not always seem to work.
Sorry but your best option is probably to get a new heater...
This thing will nickel and dime you forever now...

Heatman101

Rick, if the tank is normally plumbed for a horizontal position, and you have it standing vertically, then you are feeding liquid propane to your pilot light, hence the frosted hose etc., and a tendency for the pilot light to go out as it has too rich of a fuel to burn. There should be no vent to allow air in as propane is pressurized, and only attains zero pressure at 40 below zero farenheit. The valve you speak of should have been the liquid vent valve which is used during filling only, and is closed during any other use. Your supply valve should be in the wide open position. The pressure relief valve is only operational when the tank has been overfilled or overheated. You should have a pressure regulator between the tank and the appliance you are trying operate. Hope this helped. Marvin

it sounds like you pilot lite is to far away from the burner, make sure that the burner is sitting in it;s purch, look thru the site glass it can be moved by hitting or bumping into the out side of the gas tubes on the outside of water heater, if not, the burner assembly may have soot on it. you might also want to make sure the filters are not clogged on the shut offs that will give it less pressure then it needs to make the unit come on,, write me , [email protected]

May be That we have something we can try. first, what doesn't work most of the time? Blowing with all you mite or jumping out of the way before your hair gets singed?
I think it sounds like you might have a maladjusted ignitor. Mispositioned. Its not in the gas path. Sometimes this happens as the tungsten ignitor wears down. That can be adjusted by repositioning the ignitor so it is in the pat of the gas. Just don't test as you go. Set the ignitor so the arc is about 1/4 inch long and about 1/4 inch away from where the gass comes out. Keep clear of the access hole. The longer it takes to ignite, the more gas build up there is. Have your exhaust vent checked. restriction keeps it from drafting and drawing enought air to balance the air gas mixed to ignitable.

Be careful and be safe

The tankless water heaters require larger gas supply lines because of the on-demand consumption. While I don't know your units rating, most Propane Tankless Waterheaters require 2" supply lines. Moreover, pressure is directly related to temperature which sounds like your problem entirely; consider the run of the gas pipe from the tank and the ambient temperature. Now you see why plumbing is a hard profession to fake... =)

Sounds like you're dealing with a pesky issue. It could be a technical glitch or just a setting hiccup. Have you tried resetting the timer or checking the settings? If that doesn't do the trick, it might be worth getting a professional to take a look.U can also check some info about alphamechanicals. They got my air conditioning installation in Orangevale, CA https://alphamechanicals.com/service-area/orangevale-hvac-service/ and as I know they has to know something about bosch devices

Losing pendant displays on cool to cold mornings with your Bosch Highflow 25 EC hot water heater could be caused by temperature-related issues affecting the display module. Cold temperatures can affect electronic components, causing them to malfunction. It's possible that there could be a loose connection, moisture buildup, or a fault in the display module itself. I'd recommend contacting Bosch customer support or a qualified technician to diagnose and fix the issue.