Magnetic door switch/sensor not reliable

phareous

Member
I installed a recessed magnetic door sensor on my front door. Because it is a double door, it is located on the hinge side. It will only trigger if the door is 100% open. If the door is just half opened (still enough for someone to enter), it never triggers.
 
So I am wondering if the sensor is defective and I should replace it, or if this is just a limitation on having it on the hinge side. Any thoughts?
 

pete_c

Guru
So I am wondering if the sensor is defective and I should replace it, or if this is just a limitation on having it on the hinge side. Any thoughts?
 
The sensor is doing it's job.  It's just that the magnet is too close to the switch.  This will happen with the proximity of the sensor to the magnet on the hinge side.  Moving the magnet or switch can be a bit difficult.  Here have some switches under the thresold of the door frame probably 1" or more away from the magnet.
 
One of these might work better for the hinge side of the door.  Typically a door sensor is inside a hole 3/8" in diameter.  This contact sensor will require a larger hole (not sure on the size).
 
contactsensor.jpg
 

phareous

Member
Thanks that confirms what I was thinking about it being due to the hinge side. I'm going to go with the plunger one you suggested (although I've read these tend to be less reliable than the magnetic ones).
 
The other thoughts I had were to put the magnetic ones at the top of the door (much more work with having to take the molding off), or switching to the Elk wireless ones that mount on the door face (much more expensive)
 

pete_c

Guru
Yeah here never used the plunger types here.  Today they might be better built.  Personally didn't like the mechanical aspects of said types of sensors.
 
On one new home build I had the alarm wires predone during contraction. 
 
Front door was a double door mostly glass with a wood frame.  Alarm company put the wires over the doors and I was able to terminate them fine.  (none of the wires were terminated and I DIY'd the OmniPro 2 installation baby step wise and it works fine).
 
The top wood frame was hollow and the wires went inside of the wood.
 
I have been able to install / wire up top sensors removing the door trim on my current home.  Removing the trim slowly I didn't damage it.  Just lift up either top or bottom and go slow.  Here had 2-3" staple gun nails (no heads).  I just used finishing nails to replace the trim and used a small drill bit to make starter holes.  Note this is with wood trim. 
 
Lots of space between the wood frame and shims and insulation.  Not sure though how easy it will be to pull the wire back such that you can reroute to the top of the door.  you may need to solder an extension wire there (22/2) just a few feet.  Personally have always soldered and used heat shrink tubing (with EOL resistors) on the ends of my sensors.  I find this way uses up less space than using the crimped ends.
 
Plungers are no less reliable than recessed magnetic reeds....their downfall is paint or drying out and their actuators breaking/sticking. Actually, the guts are magnets and reeds in proximity.
 
You'd be surprised at how many poorly located recessed reeds are out there.
 

pete_c

Guru
Thank you Del.  I assumed that all of these plunger sensors were mechanical.
 
So basically the fix for the OP is to relocate the same sensor (plunger) or install a new one.
 
Here have always had the recessed sensors on the top, side or bottom of the door.
 
@ Pete
A lot of guys, especially inexperienced or lazy (electricians are notorious) will either use 3/8" recessed EVERYWHERE, even when not appropriate, like the butt of the door.  The favorite is when they drill odd sized holes (1/2" is a personal favorite....or the 3/16" hole near the edge).
 
Usually I've seen guys that don't understand the basics use rollers everywhere....and that gets them into problems. Butt side of door only. Not sliders, not top of door or in windows. Actually, they can be used at the top of the door, although they take a load of abuse from the door hitting them before they force upwards to close the circuit. I've done it a handful of times when dropping the door to install a magnet wasn't going to happen by myself and there wasn't enough headroom in door/ceiling to drill.
 

upstatemike

Senior Member
I wonder if you could use a right angle drill like is used to drill wall studs combined with a mirror stuck to the side so you can see the top of the door? Don't know if that would work... just thinking out loud.
 
Regular drill with a stubby paddle and get the magnet in at an angle. Doesn't matter if the magnet is aligned or flat, as long as it's not a T shaped install. Did that hundreds of times in the field. Don't really need to see what is being drilled...and a lot of times a twist drill isn't the best tool. Exception being a hole saw in a steel faced door.
 
R

Rickiqpf

Guest
Is anyone aware of a single pole double throw switch that works with Zwave?

We have a exterior roll shutter on our sliding door and I'd love to be able to control it via Zwave.
 
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