Bosch tankless water heater model 125B LP turn hot water on flow is good burner ignates is on NO hot water
There is a rocker arm that positions the flame to heat the water is sticking or misaligned.
all the burners lite up they sit in the middle of the unit it has worked fine for the last 4 years
Yes it lights and the arm is sticking and not aligning.
how would it get misaligned nothing has ever been changed
From usage. Calcium deposits build up. You should actually flush it with vinegar water once a year to clean it. You would fill a bucket with vinegar water, shut off the gas and water, hook the heater to a pump p and flush for about an hour.
is there any other reason this would happen ???????
It is common. Do you have well water? Usually more problems with well water or hard water. You can filter your water and flush your heater once a year.
i have been doing plumbing work for 20 years. lots of work on high end homes along with a lot of service work.
thank you! let me know if you have any other questions and remember me on your next plumbing question, i am online all the time! please leave me some positive feedback? thanks again, mike.