I recently attempted to install the T3000 on our second floor, which is a heat pump, and ran into an issue where the device would not recognize that there was a G wire connected. In fact, I was doing this setup while I was having my systems check up going on, so the HVAC serviceman even assisted in taking a look at things. During the troubleshooting we attempted to run through the detection with 2 different T3000s (I bought one for each floor), both the wiring plate as well as the devices, and both resulted in the same behavior of detecting all of the other wires but not the G wire. Additionally, I have since installed one of the devices on our first floor which is a traditional system and all of the wiring was detected correctly and is working fine.
So we also were able to confirm that the wiring was not defective (or I should say the service rep did), by touching the G wire to the hot wire and the blower kicked in. This was after the serviceman completed the setup even though the wiring wasn’t properly detected.
In the state that the T3000 was in (not detecting the G wire), everything worked fine when on “heat” as the blower was activated in that cycle without issue. However, when testing the “cool” side, the outside condenser turned on and the system started up but the blower did not activate.
As its warmed up, I have defaulted back to my existing thermostat which is working just fine for heat or cooling. Even the serviceman was stumped as to what the issue could have been.
I am including a couple of images:
Wiring for original thermostat (note the wires in the pic had been loosened before I remembered to take the picture)
That is what is odd, we tried the bypass and configured it the way it should be (heat pump, single stage, etc.) and that’s when we found that while the fan starts with the heat side of things, the fan does not activate for cooling. I think its that part that if we could solve (getting the fan to kick in during the cooling phase) then we are set here.
Oh I see. You need to connect RC and RH. There should be a little jumper in the box you can use to connect them. If not, you can use a short piece of wire.
That’s referring to your old thermostat wiring. You only had an R wire, you didn’t have a separate Rc wire. In fact, when I look closely I can see that on your old thermostat there was a jumper wire connecting R and Rc. Can you use that same jumper to connect RH and RC on the T3000?
Yes, I actually just tried that (using the jumper wire from the old thermostat) and got similar results. G not detected so went into bypass and set it up both using RH only and RH & RC in the settings, and when turning on the cool setting, everything kicks in other than the fan. Interesting enough, if I go into the settings and turn the fan mode from auto to on, the fan does turn on, but that would mean leaving the fan on all of the time, which isn’t a great solution.
Will go back through both boxes (from the 2 T3000s) and see if I find a jumper there.
I think your best bet is to use a jumper between RH and RC. Then go through the set process again, skip/bypass auto wire detection and manually configure the thermostat. If that doesn’t work and you definitely used the correct settings for your system then I’ll need to get input from some other people who aren’t available until tomorrow.
Thanks. I am fairly certain that I done that a bit earlier as far as the bypass and manually configuring the settings. Definitely interested in an other ideas. I suppose I will head up into the attic as well and make sure to grab a shot of the info on the heat pump in case that might be helpful, so if there is anything specific other than the model info, etc. while I am up there let me know.
Given the fact that the T3000 cannot tell that a G wire is connected I would advise trying first to remove the G wire at both ends (air handler and tstat) cut the end of the wire off and strip back the sheath to reveal fresh wire.
It sort of sounds like the relay is not able to provide enough power on the G wire when in cool mode, but that is a guess without being able to see settings in this case.
What model of air handler do you have? That might help.
Where can I find the information on the model of air handler (suppose even the model of the heat pump as well)? I am guessing a trip into the attic will be needed as that’s where the equipment is? Anything specific I need to be on the look out for (so I can take proper pics)?
I can also try to get back to the wire cutting suggestion as well at some point, though I guess what is confusing is that with the traditional tstat installed, everything works just fine, so not sure why it would be a power issue if it works just fine otherwise (we are using the old tstat right now so that the AC works).
All relays have different thresholds and electrical characteristics. The T3000 has some advanced features such as the wiring detection which necessitates some additional sensitivity.
Simpler Tstats are typically not nearly as sensitive to electrical variance. I’m not 100% convinced that is the issue, but it is my best guess in this case currently.
I would say just take photos of the air handler labels, the necessary info will be on there.
Now you can see the green wire in the pic above (1st wiring photo, center of the image), but I did notice a 2nd one in the back that isn’t wired to anything, then again several of the wires from the bundle aren’t wired to anything (see below). Not sure that this means anything though.
I’m not seeing anything striking there in the images that would cause an issue.
If you have the jumper in place on the thermostat, you can control the fan manually, fan engages in heat mode, but does not engage in cool mode, I’m thinking you’ve likely got a malfunctioning t-stat or the power used by the T3000/difference in relay characteristics is dropping the voltage below the fan’s operating range.
There is nothing unique about the wiring at the old Tstat in your image, it is standard heat-pump wiring.
Can you post a screenshot of the advanced and installer settings for your tstat?
So I haven’t been trying both T3000s in the past couple of days, but back before I posted and when I had the HVAC service onsite, we did try both T3000s that I have (both the devices and the backplates, in both combinations), and got the same result, so doubtful that its a malfunctioning t-stat unless I just lucked out with 2 that had the same issue. One of them is now connected to a “normal” system for the downstairs and works just fine.
Here is the pics of how the tstat was manually setup, if that is what you were asking. If you are looking for the settings on the alarm.com side, I can get those pulled. If nothing from here I can try the wiring recommendation (cut and strip) from yesterday
If you are looking for the settings on the alarm.com side, I can get those pulled. If nothing from here I can try the wiring recommendation (cut and strip) from yesterday
Yeah I am more referring to the Alarm.com settings, but most of what I would be looking for is in the images you posted. The setup looks right. The fact that the Tstat does not recognize the green wire is connected and the fan failing to kick on in cool mode strongly makes me suspicious that it is an issue with the electrical.
Cutting and stripping fresh wire is intended to ensure that there is no corrosion or wire damage that might be inhibiting it. The HVAC professional likely looked at this already if you had one out, but it is something to check.
Always be sure to turn off all power to the HVAC before removing wiring.
Beyond that, I spoke with Alarm.com support reps and they recommend having your dealer contact them to troubleshoot.
Do you use Surety for your Alarm.com service? (I don’t see a related account right now)
If not ADC would be able to walk through with your service provider and look at the thermostat’s communication with their system to verify everything is set up as it should be.
I am not a Surety customer, so I will try to work with them. They are much more familiar with the security side of things and have only done a few of the tstat installs, so they aren’t very familiar. They provided me the ADC support number but also said that I likely wouldn’t get much help as its for service providers, so I haven’t tried that yet. I suppose if the wiring part doesn’t work I can try to work with them to at least get me connected with ADC in trying to resolve it. May even try to have our HVAC service provider at the same time since the last time he was helping but didn’t want to get too far into troubleshooting since he didn’t want to charge me for installing the tstat.
Sounds good. At this point consulting ADC would be necessary. for Surety users we would be able to facilitate that.
If your dealer opens a ticket for you Alarm.com reps would be able to view system logs and hopefully help nail down the likely cause. Whether or not they are familiar with the thermostats, your dealer would be able to get targeted support started. Alarm.com should be able to provide troubleshooting steps to an HVAC provider if necessary.
