Hi,
Having some problems with our heat, while I am away on travel so I am traying to help my wife over the phone. The thermostat is set at 68 but the house is only heating to 65. The furnace is kicking on but seems to be turning off too soon. Some of the time the thermostat indicates the system is running, but it really is not. If I reset any of the safety switches or turn it off an then back on, the system kicks back on.

We recently replaced the filter, and also had someone out to look at it because the ducts were made some bad vibration noises... when he was out he restriced the airflow to several of the vents to help heat the house more evenly.

The air filter was replaced about 1 month ago and the service guy was out about 2 weeks ago so I don't know that either of those would have an affect now.

Thoughts?
Thanks.

Post brand & model #. What safety switches are you resetting?

Furnace is an armstrong, therostat is a honeywell.

On my unit if I take one of the bottom of the 2 covers off there is a button that turns the unit if it is not pushed in, also there is a 'light' switch that turns off my unit.

It seems like the correlation is that when I turn it off, and back on-it gets the heat to start back on.

The interlock switch (button behind the access panel) and the "light switch" interrupt power to the unit, and this action is probably cancelling a timed "lockout" imposed by the self-diagnostics of the circuit board control. You had a service visit 2 weeks ago - was this because of the problems you are experiencing, or did the problem develop subsequently? Without a model # I am limited in offering suggestions, but the unit may be equipped with a diagnostic LED that would help in identifying the problem.

The unit is a armstrong air untra V advantage 93 45650-001