Door switch for thermostat?

[GR8Dane]

Hey guys.

I've got a dedicated central A/C and furnace setup in my garage all running off of a programmable thermostat. Does anyone know of a slick way to tie a door switch to my garage door and to the thermostat to tell it to turn of when that door is open? Either that or a built-in shocker that will zap my wife and kids when the leave the garage door wide open while I have the system turned on!

I've found some commercial applications but they are very expensive or just operate a series of dampers to shut-off the air flow.

I think it would need to be smart enough to actually tell the thermostat to turn the system off so that it can deal with any rapid open/close situations. For example, if I manually turn off my A/C for a moment and then back on, the thermostat always waits a few minutes before kicking back in to let the compressor adjust. I'd be happy to deal with that delay over having it just run when the door is open. Obviously the ideal solution is one that shuts off the system only after the door has been open for a few minutes.

Thanks!

 

[Travis E.]

If you have knowledge of wiring you could put a limit switch on the door tied into the stat. You can also put a timer on it as well.

 

[GR8Dane]

Thanks Travis.

I think I can wire up the thermostat to a radio shack door switch easy enough. I'm just not sure where to tie it in to the thermostat. Is there a particular wire I should be looking for?

 

[nehog]

This should be trivial, a micro-switch on the track that when the door is closed the switch is closed too. Then wire the switch in series with the thermostat.

They make (try Grainger) switches already setup and ready to use with a roller end. A pre-made switch might be more expensive, but that's not a big issue.

Another alternative is a unit that automatically closes the door if left open. I think Northern Tool has one in their catalog.

 

[Cast Iron Nuts]

Try mounting an end switch to the rail of the over head door and run your red 24 volt wire so when the overhead door opens it pushes the end switch open and breaks the 24 volts to the air-handler.

 

[Cast Iron Nuts]

ffs cant type fast enough around here. BTW Good sound advice nehog

 

[GR8Dane]

Sounds easy enough. I'll get a door switch and mount it to the garage door to sense when it is open. It sounds like I need to connect it to break the circuit on the red wire.

I'm assuming if I break the circuit on the red wire the thermostat will deal with shutting everything down appropriately in the air handler.

The auto-closer is something I've considered too. Mainly due to theft concerns, but it would help with this also. I just need to get my remote keypad working again.

Thanks guys. I'll let you know how it turns out.

 

[rickairmedic]

Yes the red wire is the one you want to break with the switch it is the 24V positive wire that comes from your furnace to the thermostat . This in turn through the thermostat powers the AC or Heat depending on how you have the thermostat set. the white wire is heat the yellow wire is AC and the ghreen wire is for the fan .



Rick

 

[Eggman]

Might want to turn the power off to the furnace before messing with the thermostat wires. Otherwise you may have to replace a 3 or a 5 amp fuse on the board or worse yet, a burned up transformer.

HTH,

Eggman

 

[GR8Dane]

Thanks Rick and Eggman. At least now I know I'm messing with the right wire.

I'll be sure to hit the breaker on the HVAC before I do any work.

Thanks again.

Dane

 

[rickairmedic]

I would get a length of 18/2 thermostat wire long enough to make the run from the thermostat to run to your switch. You can get this at homey desperate or Lowered expectations.


Rick

 

[GR8Dane]

I would get a length of 18/2 thermostat wire long enough to make the run from the thermostat to run to your switch. You can get this at homey desperate or Lowered expectations.

Rick

That's a good idea. I still haven't mounted the thermostat on the wall. The installers left a spool of the wire attached to it so I can probably locate it close by. Thanks!

 

[Byron]

What about the blower door switch ? Just add one to your garage door .