What kind of bell is it? A Ding Dong Bell?
When it works well, does it make sound like a Ding/ Dong, When pressing the switch make "Ding" and release make "Dong"?
Open up the door bell. check the solenoid coil, (see the picture from the link) you may have the coil melt, and the plunger is sticky.
if it is melted, you may need to replace it, or put a drop of cooking oil to lub it. but not too much oil. the following site very helpful..... Post What you see and result. so every one can learn.
http://home.howstuffworks.com/doorbell3.htm
good luck,
When it works well, does it make sound like a Ding/ Dong, When pressing the switch make "Ding" and release make "Dong"?
Open up the door bell. check the solenoid coil, (see the picture from the link) you may have the coil melt, and the plunger is sticky.
if it is melted, you may need to replace it, or put a drop of cooking oil to lub it. but not too much oil. the following site very helpful..... Post What you see and result. so every one can learn.
http://home.howstuffworks.com/doorbell3.htm
good luck,