Armstrong furnace lockout

The Armstrong Furnace will not work if it is locked out, so the unit can no longer turn on. When a furnace locks out, it’s typically because the thermostat has been set to its maximum temperature and there’s no need for the furnace to keep running while the home remains heated.

When a homeowner experiences an Armstrong furnace lockout due to an open limit, they should first reset their thermostat so that the furnace can resume cycling and heating up their home.

Armstrong has put in place a limit on the number of times you can open the door of your furnace after the initial startup. This is for safety purposes to avoid carbon monoxide build-up in the furnace chamber. It is important that customers understand what this means and are able to contact us for assistance if a lockout occurs as soon as possible.

1) Customers should not open the door more than 3 times, total, after the initial startup.

2) If a customer opens more than 3 times and their furnace will not light back up, they need to shut off power at the breaker panel or call our 24/7 emergency line

3) There are two reasons that can cause a lockout – in order to determine what action needs to be taken, it is necessary to contact customer service or an authorized service technician

In order to avoid the risk that the furnace will unexpectedly shut off as a result of the lockout, it is important to be vigilant.

Armstrong furnaces can malfunction and stop working if they are not monitored carefully. One of the most common ways a furnace can stop working prematurely is because of an open limit lockout.


“Inspections, Installations, Repairs & Maintenance”