Door bells: two chimes versus three

[Brian Elfert]

When I wired my new house six years ago, I wired for three door bell chime units. I only hooked up two chime units originally because the basement was unfinished.

I hooked up the third chime unit yesterday and now the chimes all just go "ding" instead of "ding-dong" like they should. I unhooked the third unit and everything works again.

Do I just need more power from the transformer or could it be something else? I put in the largest transformer (15 watt) Home Depot sells when I originally wired the house. I noticed Menards has a 20 watt model.

Could it be a wiring issue? My dad was over and hooked up the third chime and I noticed he wired it in parallel. (He used to be an electrician so he should know.)

[Jim O'Dell]

I'd guess not enough power to run all 3. Could you add another transformer in for the 3rd bell, and still use the single button at the door? Last door bell I hooked up was a RF unit that had no wires, ran off batteries. Jim.

[David G Baker]

Brian,
Some door bells have a diode in the button, don't know if that could cause the problem. I don't think that another transformer would do anything because the buttons are just switches that form a loop that is closed when the button is pushed.

[Brian Elfert]

I'd guess not enough power to run all 3. Could you add another transformer in for the 3rd bell, and still use the single button at the door? Last door bell I hooked up was a RF unit that had no wires, ran off batteries. Jim.

I think my dad somehow added a second transformer at his house for a similiar situation.

If I have to buy a another transformer I will get the 20 watt instead of the 15 watt and try that by itself before I wire them together.

Brian Elfert

[Josiah Bartlett]

You don't have a big enough transformer-

The "bing bong" doorbells work by solenoid action- energizing the coil with the button pushes the armature out, striking one of the gongs. That gives you the "bing". Letting go of the button releases the armature and the spring makes it overshoot through the solenoid coil and hits the other gong, giving you the "bong". Since you now have added 1/3 more load, the transformer doesn't have enough voltage to drive the armatures all the way out to hit the "bing". A bigger transformer will fix it.