Official Insteon/Venstar Thermostat How To Thread

followup to my own post:

i saw that i was one version behind and i have now updated to 2.5.0b19

this latest version adds an option in the device setup for thermostats that will poll automatically. the only difference i can see between this and the date/time action i was using previously seems to be that the built-in polling does not write anything to the logs.

according to the logs, the applescript "status request <device>" for a thermostat seems to cause four separate status requests: mode, temperature, humidity, and setpoint. and NOT fan mode. a few possibilities come to mind:

a) fan mode is a separate piece of status information that indigo would have to request separately. it is not currently requesting it, which explains why fan mode is not currently being tracked within indigo.

b) fan mode somehow is encoded along with mode. indigo is fetching it but just not updating it currently.

c) fan mode is simply not available via the insteon interface so indigo will never be able to query it. this would be a bit odd because it would mean that they provide a way to set something but not get it.

so as things stand right now, i don't see any way to get the fan status, not even from applescript.

to work around this problem, i could possibly just dispense with ever controlling the fan manually (from the thermostat), but i'd really prefer to be able to get the fan state from within indigo.

[matt (support)]

is this an oversight? perhaps not considered important enough to warrant having an action? or should another action be added called "get fan mode"?

The thermostat adapter does not have a command to get the fan status. Instead, if the auto/cool/heat mode is OFF, then when Indigo asks for the mode status it will return if the fan is in the AUTO or ALWAYS ON mode. But there is no way for Indigo to poll out the status unless the mode is OFF. Indigo treats the fan status as an independent state from the auto/cool/heat mode (because it should be), but in this case it is impossible for Indigo to determine the value via polling. I put in a request a while back for this to be changed, but it didn't make it into the first rev of the adapter.

Regards,
Matt

My existing thermometers are 2-wire (Battery operated + Heat only). Is there a simple way to provide the 24 V power locally with a modest 110V transformer - does any one know of an appropriate/approved unit?

If I do have to run new 3+ core wires (which is going to be tricky) is there a standard unit for providing the 24 V centrally?

Thanks, Rick

[matt (support)]

My existing thermometers are 2-wire (Battery operated + Heat only). Is there a simple way to provide the 24 V power locally with a modest 110V transformer - does any one know of an appropriate/approved unit?

I would imagine, but don't know for sure, that a 24VAC sprinkler valve plug-in adapter would work.

Regards,
Matt

I have just taken delivery of a Venstar T1800 (7-day programmable thermostat) plus INSTEON Thermostat Adapter and am having trouble with the installation. I looks like I am one wire short even though I have 5 wires. I have the following wires: Y, G, W1, RC and RH, but there is no common (C) wire.

There is no simple 'R' wire, so I think I have separate 24 VAC lines for heating (RH) and cooling (RC). Is there some way to combine the RH and RC wires to a single wire which will free up a wire to serve as the common? Or do I have to add a sixth wire to serve as a common?

Yea, you need the VenStar Add-A-Wire kit. Basically all the places that sell the Venstar thermostat also sell that part, so it should be easy to find.
There are some pics of that thing on my blog http://blog.x-caiver.com/2008/03/automated-hvac.html.

I had enough wires, but one of them was apparently short-circuited somewhere deep within the wall / attic, so I had to clip it and use the add-a-wire.

Thanks DPattee. In the end I decided to run a new wire, in part because of the lack of a common wire, but also because I have a whole house humidifier and would like to take advantage of the Venstar's remote humidity control. I actually ran a second 5-conduit cable so I now have 3 spare wires for future expansion!

But I still have an installation problem. The Venstar 1800 has a single R terminal, but I have two 24 VAC lines: one from the furnace labelled RH, and the other from the air conditioner labelled RC. The Venstar installation manual does not describe this scenario. Any ideas what do I should do now? Do I connect the two? Doesn't sound prudent, but I have no idea what else to do.

Exactly what lines do you have coming to your thermostat? What are the lines labeled, and where do they go if they don't all go to the same place, and what were the labels that those lines connected to on your old thermostat?

In my house all the lines came from the control circuit that was built in to the heater, including the A/C control line. The control circuit in the heater was then wired up to the A/C, the heater, the fan, and the electric air filter.

When I was getting mine together, I made a little chart like what follows:
Thermo Connector - Wire Color - Controller Connector
G - Green - G
Y1 - Yellow - Y
etc.
Mine was a little more complicated since I had a defective wire in my 5-wire bundle so I had to wire up an Add-A-Wire. I also recorded what the label/color settings for the original thermostat, which were slightly different since it didn't use all 5 wires and had a battery, were so that I had all the info I could possibly need to get things hooked up correctly.

I am also in the same situation as others when trying to install the Venstar T1700 and finding out that you need a Common Wire to complete the installation. This is something that is not noted in the manual (that I could find anyway). I contacted Venstar directly and was told about using the Add-A-Wire but if you look at the instructions for Add-A-Wire it specifically states that you CAN'T USE Add-A-Wire for either the Power or the Common wire. I am a bit concerned because of this official disclaimer, should a fire start or equipment get damaged, that disclaimer could put me on the hook. I have pasted the information directly below. I am interested in anybody's thoughts on this issue...

Additional Specifications

* Includes Yellow, Green, Blue wire splice (directionally sensitive)
* Includes 4 wire nuts
* Wires running from Add-A-Wire accessory are 9" long
* Maximum distance for Add-A-Wire using 18-gauge wire is 100ft
* Makes one wire work like two
* Mounts inside equipment (not for outdoor use)
* For use with 24-volt HVAC systems
* Cannot be used as "R" power or "C" common wire "

geoff

Should I consider running a new wire so that I can add the COMMON wire, where would it go? In my house, I have an air handler in the attic through which blows both the AC and Hot air, in the basement is the boiler. I presume it would go to the air handler since it operates regardless of using heat or AC but I don't know for sure.. also, what kind of wire would you use? Any information will be appreciated...

Thanks for taking the time to read this...

Geoff

I contacted Venstar directly and was told about using the Add-A-Wire but if you look at the instructions for Add-A-Wire it specifically states that you CAN'T USE Add-A-Wire for either the Power or the Common wire.

That's right. You use hte Add-A-Wire to add an extra signal path. For example if you have:
1) Power
2) Heater
3) A/C

You would use the Add-A-Wire to run the Heater & A/C over the same line. Then you would use the old wire to the heater as your new common.
(which is one of the reasons I suggest making a little chart of connector/color/connector, because as soon as you use the Add-A-Wire some of your wire color information gets lost since you aren't using the wires for their original purpose)

Smarthome has a Thermostat Power Supply Module http://www.smarthome.com/110807.html

"Use this Thermostat Power Supply Module for thermostat retrofits where a 5th "common" wire is needed, but not available. It increases current to thermostat using existing wires."

Has anyone used this?

Smarthome has a Thermostat Power Supply Module http://www.smarthome.com/110807.html

"Use this Thermostat Power Supply Module for thermostat retrofits where a 5th "common" wire is needed, but not available. It increases current to thermostat using existing wires."

Has anyone used this?

That's not a generic 'add-a-wire' solution. That is specific for HAI devices that have the ability to run by stealing power from the existing control lines. It makes sure that the power going down the lines is sufficient to keep the thermostat powered up, even when some of that power is being redirected to the active heater/A/C terminal. It wires up only at the control circuit (i.e. the heater), while a generic 'add-a-wire' would actually need parts on both the control and thermostat sides.

Exactly what lines do you have coming to your thermostat? What are the lines labeled, and where do they go if they don't all go to the same place, and what were the labels that those lines connected to on your old thermostat?

System description: I have a Lennox G8Q3-80-3 forced air gas furnace, built in 1991, and a Kenmore central air conditioning unit (model unknown), which is no older than the furnace, and possibly newer.

Thermostat: I have 6 wires including the new common wire that I have just pulled. The original 5 as they were labelled on the old thermostat are: G (green), RH (red), RC (black), Y (orange), W (white). The new C wire I installed is red, but I labelled it C to avoid confusion.

At the furnace: Mounted to the side of the furnace is a blue Honeywell box with a terminal strip which I believe is a transformer. Here is a photo:



In the photo you will notice there are three brown conduits. The one on the left is a new one that I installed. It has only one red wire connected to the C terminal on the transformer, and the other end is sticking out of the wall upstairs waiting to be connected to the new Venstar 1800 thermostat. The remaining 4 wires are unused spares.

The second brown conduit has two wires:
1. a black wire connected to the C terminal.
2. a white wire connected to Y.
These both lead out of the house and disappear into the air conditioning unit.

The final brown conduit has three wires:
1. a green wire connected to the G terminal, which runs up to the thermostat; so this is the wire labelled G at the thermostat.
2. a black wire connected to the R terminal, which also runs up to the thermostat; so this is the wire labelled RC at the thermostat.
3. a red wire connected to Y, which is connected to an orange wire inside the furnace, which in turn runs up to the thermostat. So this is the wire labelled Y at the thermostat.
You can see where the red and orange wires are connected inside the furnace in the bottom right corner of this photo:



The remaining two wires that come down from the thermostat are the red and white ones. The red one (RH at the thermostat) is connected to a red wire inside the furnace, and the white one (W at the thermostat) is connected to a blue wire inside the furnace. You can see those connections in this photo:

As a follow-up to my post, here is a wiring diagram for connecting a Venstar thermostat to a dual transformer system: