My main burner will not light. After the hot water heater power cycles three times, the hot water heater shuts down and the following error code is displayed:

100110 which the owner's manual says is System Lockout

Things I have tried:

Repositioned the igniter assembly several times
Replaced the igniter assembly
Tried starting using different temperature settings

Every now and then the burner will light but only for a few seconds.

Can anyone help?

I am having the same problem with my heater. Any chance you got yours resolved?

Try replacing the thermocoupling.. It's a cheap fix- probably less than $10.00. Sounds like it is failing. JG