The simplest approach I’ve seen, which is what I implemented.

  1. monoprice contact sensor (these have a screw terminal terminal for external switch)
  2. external reed sensor (I got a pile of these from ebay
  3. double sided sticky tape

connect the external reed switch, then tape it to the doorbell coil.
It was literally a 5 minute job, for under 30 bucks.

Is there anyway I could ask for photo of your setup? I understand the parts, I am just not fully picturing your setup.

sure, check back around 4PM PST, I’ll add a picture to the above post.

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@malthus86 @Mike_Maxwell

A connection diagram would also be very useful.
If only I have waited a month for this thread … burnt a Everspring sensor last month after connecting it without a relay :frowning:

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well that’s the beauty of this setup, nothing connects electrically to the doorbell.
there’s two spare screw terminals (and only two) inside the monoprice sensor. These connect to the reed switch leads, of which there’s only two. The reed switch is nothing more than your typical dumb magnetic door/window contact. The doorbell coil develops a magnetic flux field when the button is pushed, this is what makes it go ding dong. The reed switch is placed near the doorbells solenoid coil, so when the coil fires, the reed contact is closed.


I am assuming that the reed switch goes at either end of the solenoid - can we please get a photograph of this if possible?

Nope, goes on the side, I’ll post pics in about an hour.
Remember your HS metal filing experiments?, the flux from a solenoid forms a closed circuit loop.

So placing the reed switch on the side still includes the switch in the flux field.
Granted they’re not as dense, but it’s more than enough to trigger the switch.


In my case the doorbell cover is able to enclose the monoprice contact sensor.

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I put a ST Multi on one of the two chimes to detect vibration. Works great but that chime does not really ring anymore. . . I wonder if you could fit the contact sensor where the read sensor is that you would not even need the read sensor?

If it fits, then yes, wouldn’t fit in my case.
That also makes changing the battery a bit more interesting.

I inspected my doorbell and this is not possible from behind anyway. Maybe i could mount it to the cover in the front but since I managed to relocate the ST muti and now both chimes sound so I may wait for another day to try that.

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I don’t suppose you’d be willing to sell any extra would you?

Sure, they’re like a buck each, pm me info and quantity, I’ll sell you 1 or up to 5.

I just used this same setup after experimenting with a few other options. I slightly modified the device type and kabam! It works! Thanks for the idea.

I just set up my doorbell chime like what @malthus86 did, except I used an Ecolink sensor with one of those relays. Works perfectly. I tweaked one of my other device types to use for the doorbell, as well as using the Notify Me When app for notifications. I was using a MIMOLite, but I needed to re-purpose it to control a water valve. This solution works better in my opinion.

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Any EE gurus able to help me figure out how to rig this without the actual chime, but with a lighted doorbell? I’m thinking I could put a couple of resistors in the circuit to simulate the chime, but I think there is more going on. Trying to wire the relay in like @malthus86 with a lighted button, but without a bell allows enough current through to constantly trigger the relay. Sure I could just wire the button straight through to the z-wave try contract sensor, but then I would loose the lighted button, and in fact the button light might even make the contact sensor think it is closed on its own.

Do you have a voltmeter? You can test the voltage of the wires into the bulb and wire in an appropriate voltage relay.

More than likely the relay being used requires less current to operate than the light. Door belt coils are pretty large, requiring a fair chunk of current to trip. Personally, I would pull the ding song stuff out of the existing doorbell, then position a small reed contact on the exterior of the doorbell coil, this would then wire to the aux contact input of the contact sensor.
When the doorbell button is pushed, the (now silent) doorbell coil will energize, tripping the read sensor. This is the exact setup I (and many others) have used, except my ding-dong bits are still in place…, pun intended…

@malthus86, I’m using the same relay you linked above at Amazon. I have one of those tri-volt transformers (8v,16v,24v), unfortunately the button won’t light at 8v and, at 16v whatever current the button light leaks through is enough to trigger that relay. I’ll try measuring the current, looking up the specs of that relay and throwing some resistors in. Bummer that Radio Shack has been shuttered.

@Mike_Maxwell, I’d go that route, but never had a door chime to begin with. I think the previous owners of my house drywalled over during a kitchen remodel. The transformer and the wire run to the door were still in place though.

I’m using a custom device type and having a hell of a time getting the doorbell to “release” after the dry contact opens. I think this has something to do with some throttling ST is doing, but could be my code is shit too. Anyone have any suggestions?

    // "Push" the button when the contact closes
def sensorValueEvent(value) {
	log.debug "Pushing button"
    if (device.currentValue("contact") != "closed") 
		sendEvent( name : "contact", value : "closed", descriptionText: "$device.displayName was Pressed", unit : "" )
		def fireTime = new Date(new Date().time + 7000)
        runOnce(fireTime, "releaseButton")

// "Release" the button
void releaseButton() {
	log.debug("Releasing button")
	sendEvent( name : "contact", value: "open", descriptionText: "$device.displayName is Waiting")