My Pittway Class 2 plug in transformer for my home alarm system was warm and turned brown. Today I replaced it with a new transformer(exact same type) and within a few hours it has starting getting warm again. Is that normal? When I unplugged the old one I notice that the outlet cover was a little dark. Is that a sign that the outlet needs to be replaced or a result of the old transformer? This is an Ademco alarm system that is around 10 years old. The battery was replaced a little over a year ago. Should I be concerned with the new transformer getting warm so soon after being plugged in. 120V 0.3A 16.5VAC 25VA

Mike

Transformers operate on inductance and as such create heat when drawing power.

An alarm system should not draw enough power to cause a transformer to be warm. Suggest you have the system checked for a possible short to ground.

Or possible faulty battery charger circuit.

You might want to get it checked, like hkstroud mentions. However, I have seen a similar situation twice, one in a residence and one in a business. These transformers have a tendency to get pretty warm. I would get it checked just to be safe.