My hw heater keeps going to vacation mode. When I reset it, it fires up but shuts off after a second or two. I cleaned the igniter/sensor and the problem went away for about 6 months but now it's doing the same thing again. Do I need to replace the igniter/senser?

Need to know the name brand and model number on plate at front center of heater... no need to post the serial number.

Also, how old is the heater? If unknown, do you have an open combustion chamber (remove door and you can reach into the combustion chamber) or a closed combustion chamber (can remove door but can't get access to the combustion chamber without removing another metal plate with a glass window in it?

Let me know...

Mark