Water heater burner question

[MichaelG]

I’m replacing the thermocouple on my water heater, when I removed the door the seal was brittle and broke into pieces (see image). There is another pad/gasket on the outside of the door that looks like it helps but it’s not the inner seal. I thought the door blocked all air/gas from getting in/out but as I was taking off the old thermocouple I noticed the 3 wires that were near it were all held in place with a metal block and not any type of rubber seal. So my question... is the door okay to go back on? That block couldn’t have made a good seal so wouldn’t some amount of air be getting in? There are 3 picture to look at. Two are of the door and one is of the block that had the 3 wires

 

[Terry]

 

[Sponsor]

 

[MichaelG]

Thank you! Having that visual was really helpful

 

[Dj2]

The door is there to protect against burner fire. In the old days, there have been many burn accidents from an open burner.
If the grommet is damaged, you can just stuff the opening with some aluminum foil, but a better idea is to call the mfg, and if you are under warranty you will get new parts. You can also buy parts to fit your model on line.
While you have the burner out, clean the burning chamber - dust, dead insects, whatever you find - get it out. Make sure the vents are clear of dust and obstructions, all around the water heater. Believe it or not, the burner needs oxygen to burn.

A word about the thermocouple - it has to sit in exactly the same position as the old one - same distance from the pilot light, to operate correctly.