Bosch and minimum water flow

by Ernie Guevara
(St. Paul MN USA.)

Had a Bosch heater for 15 years. In the last 10 years, keep getting error code A2 - flue gas temperature too high. Sometimes I have to reset several times before it actually works. Then it will work for several months with no problems.

My main problem is that this heater works on the principle of water flow. It needs a minimum of 2 gal per minute water flow and if less than 2 gal/min. it shuts off. This means you either get hot water or cold water, no chance of Luke warm water because by turning down the hot it reduces the water going thru the water heater to less than 2 gal/min.

Just waiting for some cash reserves to build up so I can get back to a regular water 40 gal tank water heater.

Comments for Bosch and minimum water flow

Average Rating starstarstarstarstar

Click here to add your own comments

Apr 15, 2018
Bosch water heater FIXED!
by: Ernie

A2 - flue gas temperature too high.

Short answer: it works perfectly now.

Called Bosch tech support and was told to replace the temperature sensor that wraps around the top of the heater (thick white wire). The replacement sensor is a small square sensor (about an inch square) and mounts differently than the old wrap-around type.

Now we get hot water all the time, no interruptions, even lukewarm water.

Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Bosch.

Find Trusted Plumbers & Get Free Quotes