It might be triggering by the fluctuation in the water pressure.

Maybe there is some sort of adjustment for this?



wrote in message
oups.com...
Howdy ya'll,

My wife and I just built a home and moved in. We're using the Bosch
pro tankless 635 water heater. I notice every time the cold water is
demanded, ex- flushing any toilet or just turn on a cold water faucet,
this dang water heater fires up for about 15 seconds. It shouldn't do
that unless there is a demand for hot water. Is this normal???