Hayward H400 heater help

[OCH400help]

My Hayward H400 heater won't allow me to set water temp above 89 degrees. Any suggestions or ideas?

 

[OCH400help]

When the flame is on, Is it normal for the internal side walls of the combustion chamber to glow red in a couple of spots?
Also, the digital temp control panel will not go higher than 89 degrees. help it's a Hayward H400 about 15 years old.

 

[ajw22]

Let’s see what @1poolman1 says.

 

[1poolman1]

When the flame is on, Is it normal for the internal side walls of the combustion chamber to glow red in a couple of spots?
Also, the digital temp control panel will not go higher than 89 degrees. help it's a Hayward H400 about 15 years old.

NO! That glow means that the refractory material (fire brick) that keeps the flame where it belongs in the chamber is cracked/burned out/gone. It is new heater time. It is dangerous to use a heater like that.