Problem and flashing display on AO Smith GAHH 50
I have the tank-type gas water heater from AO Smith manufacturer, model Effex GAHH-50. This is the high efficiency unit with the atmospheric venting and air intake chamber.
The problem is that the water heater is not working. There are "heating" and "open" flashing lights on the electronic control display, and I am having hard time figuring out the meaning, so I will try to troubleshoot it by myself and avoid calling the plumber or technician.