My doorbell stopped working. I tried replacing the transformer, but noticed it got very hot when I connected the wires that go to the chime.

I even bought a second transformer and it is also getting very hot.

The wires at the chime and to the door bell ringer are disconnected and hangling loose, so I know that there can't be a problem on that end.

Is it normal for a doorbell transformer to get hot? I am talking hot enough that I can't hold it. I am afraid of starting a fire.

What could be wrong?

Transformers usually get warm but not HOT. Are you sure your not hooking in high voltage on the secondary side? I would check that first.

Sounds to me like you have two wires touching somewhere along the wiring system.
Take the door chime off the wall use a short piece of wire and touch the two terminals that make the chime work. The best way to do this is to connect the wires to the transformer, Cut one of the wires and strip it so that you have two exposed wires. Connect the other ends of the wire to the chimes. Touch the to stripped wires together for a second and see if the chime rings as strong as it should. Leave the system alone for a few minutes and see if the transformer gets hot.
If your chime is not as loud as it was with the old transformer you may have about a transformer that does not have enough power. Look at your's and see if it says 40 VA on it, if so that is plenty.
If every thing works connecting it this way then the thing to do is disconnect all wires in the real doorbell system, I am not talking about the one you made to test with. Use an OHM meter to see if your wires are shorted together anywhere.
You can also use this to check your wires to make sure that you are connecting the wires to the right terminals.

With door bell NOT pressed, disconnect wire from secondary, and look for spark, touch to transformer, should not be sparking or have load on it until button pressed.
Verify Voltage and VA rating. Can increase VA but not voltage.

I am experiencing the same problem, I believe. When I first hooked up my new doorbell chime and new doorbell button, I noticed that the button was quite hot. However, I assumed that was normal and left it connected. After about two weeks, the doorbell button light went out and my wife noticed a buzzing coming from where the doorbell chime and transformer were located. When I took everything apart, the first thing I noticed was that the transformer was VERY HOT. Also, the door bell button was a closed/shorted circuit (like it was permanently pressed down) and the doorbell chime was a closed/shorted circuit. Also, upon closer inspection, the doorbell chime showed some melting in some places.

I was extremely alarmed by the temperature of the transformer. It easily could have started a fire if it was close to anything flammable. I've determined that the buzzing sound that was happening periodically was the sound of the transformer as it was heating up and then entering its thermal safety shutoff mode. First of all, it should have shut off at a temperature much lower than it did. But, I began trying to understand why it was heating up in the first place. When I measured the voltage connected to the transformer, it was 120 Volts A/C. But, the voltage coming out of the transformer is 21.2 Volts even though it was supposed to produce 16 Volts. So my theory is that the 21.2 Volts overheated the cheap light in the doorbell (since it is expecting 16 volts) and eventually caused it to short out. Once that happened it was like putting a wire directly across the terminals of the transformer and it got overheated and melted the doorbell chime which was mounted directly in front of the transformer.

So, to fix this problem I either have to find a transformer that produces the appropriate voltage (16 V) or a doorbell button that won't fry itself if it gets more than 16 V. Personally, I think a doorbell button should be designed to handle a wide range of voltages before it frys itself and further that it should have a fusible element that creates an open circuit before shorting out. I am currently looking for a doorbell button that is not lighted. It's just a switch; I don't need a light that puts my whole house at risk.

So, to answer your question, I would check the voltage being produced by your transformer. If it is higher than 16 Volts, you may have the same problem I just described above and you can consider the options I've mentioned.

James

The screws are so close they can short and be the same as holding button down.
The voltage on tranformer will be high without a load, this is normal.
I have had some doorbell or intercomm systems that have to have a non lighted pushbutton, or remove the bulb. To do that:
Untwist little aluminum retainers on back of pushbutton, separate, remove bulb, reassemble.

HVAC, thanks, everythings OK down here. Good to hear from you. Take Care.

Recently My door bell rings for no reason... could this cause a fire?

Remove the door bell switch, and see the screws are not touching. If doorbell doesn't sound with pushbutton removed, problem is at the button.

The door bell is about 9 years old so I wouldn't think that the screws wound just now start touching. Thanks, my concern is, could this cause a fire?