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.