What is this component? Rectifier?

 

Maybe a bridge rectifier?

 

Bridge rectifier.

Converts AC to DC.

You will see four leads underneath marked ~ ~ - +

AC goes in at the two ~ leads
DC comes out of the + and - leads

EDIT: JohnInTx got there first

 

Maybe a bridge rectifier?

Seconded.....

Edit: Make that thirded...

 

That what I thought, apparently when the 120vac. supply voltage is off for 15+ min. it does not function when supply voltage is applied again.
I have found by heating the rectifier it then starts to work again, until supply voltage is off.
Thanks for the info!

 

If you used a hair dryer to heat the rectifier, there is a chance you heated the NTC thermistor (grey round object on the left of the pict). They are used as to limit surge current. It to may be faulty as the resistance is suposed to drop as its heated.

 

That sounds more like the culprit. Thanks for saving me a second guess.

 

If you used a hair dryer to heat the rectifier, there is a chance you heated the PTC thermistor (grey round object on the left of the pict). They are used as to limit surge current. It to may be faulty as the resistance is suposed to drop as its heated.

I'm sure you meant a NTC. A PTC increases its resistance with rising temperature.