When you say "Function Lock" I am not sure what you are looking at. If it the Child Lock feature, you should be able to turn the stove off and push the Child Lock button to turn it off. Some of the error codes on Rinnai's look like tempertures,i.e. 60, 68, 11. I am not sure about the 263's but they should be just like a 556F. If you have a owners manual you can find all the codes. The Rinnai web site can help you get a manual if you don't have one.
Answers & Comments
When you say "Function Lock" I am not sure what you are looking at. If it the Child Lock feature, you should be able to turn the stove off and push the Child Lock button to turn it off. Some of the error codes on Rinnai's look like tempertures,i.e. 60, 68, 11. I am not sure about the 263's but they should be just like a 556F. If you have a owners manual you can find all the codes. The Rinnai web site can help you get a manual if you don't have one.
Tom