My Laars Endurance boiler (or water heater, not sure about the right terminology) is stuck on L.O. My super tells me that means it's on Lock Out. This has happened a number of times before, and I believe as a result he once replaced the ignitor.
I have attempted powering the unit on and off, and when I power it back on it goes to Lockout immediately.
We recently had a power outage in my area, so I'm not sure if that could be part of the problem...my super said it is but that sounds too convenient.
I'm tired of hearing my super's excuses, and would like to possess some knowledge so I can help myself now or in the future.
LO does mean Lock Out. It comes up from a variety of things. If it comes up immediately after hitting reset I would say it's more than likely a control or wiring problem. You can do an internet search for Laars Endurance Manual and walk thru the steps to find the fault.