Automated thermostat for RV

Hi-

What I am trying to do is turn my LP gas furnace on by a cell phone in our RV, before we get to camp site so RV is warm. I have found a GSM relay that will allow me to do that as long as I buy a prepaid SIM phone card for the GSM relay.

Here is the relay that I believe will work
GSM-RELAY Remote control switch (gsm controller)(relay control switch)

It has 7 sets of Normally open contacts, that close when it gets a phone call or text message. I would like some help on how to wire the GSM relay in with the 2 wire thermostat in the RV. once I get to the RV I want to use the thermostat to control the furnace, just use the relay device to warm it do set temp on thermostat before I get there. Will I need to add external relay or 3 position switch to make this work? If you could supply a wiring diagram that would be great!

 

There really isn't a diagram needed. That module has seven controllable relays. You could use it to control the furnace.

We would need to know how your current thermostat works.
Is it just two wires ?
How do you turn the furnace on and off ?

 

I believe there are web based thermostats commercially available. Have you checked these out?

 

This is in an RV. Can be kind of tough to get reliable internet service.

 

wifi thermostats aren't an option in my situation, like stated no internet service. Right now I am just using a digital 2 wire thermostat ran by AA batteries. I just want to be able to use stat independently of the GSM relay once I get to the camper. I was thinking somehow adding a 3 position switch of another relay. To have a normal operation of thermostat to control furnace, and in other position have the GSM relay turn on heater until it reaches temperature set on thermostat. hope you can understand what Im trying to say.

 

Very basic. You always need the thermostat inline so that when you are away and returning the RV won't overheat.

When the single pole switch is open..... there is no heat until the GSM switch closes.
When the single pole switch is closed.... the GSM switch has no effect on the heat.
The thermostat is always active.