TMR Rudy Posted January 8, 2015 Share Posted January 8, 2015 I have just installed the second (shipped under warranty) Insteon Thermostat. I have a question, does the grey display disappear during heating cycles of the furnace. I find that when the furnace is heating and then runs the fan, the thermostat goes blank after about 30 seconds, and then once the furnace blows out heat, the thermostat turns back onto the blue screen and acts as normal. This is happening on each cycle when the temperature falls and the furnace needs to run to bring back the set temperature. Is this by design? Do you think I have another faulty thermostat? Possible temperature gauge issue with the actual furnace? Trying to figure this one out. Wiring configuration attached. Link to comment
larryllix Posted January 8, 2015 Share Posted January 8, 2015 (edited) I can't be sure as I can't see the terminal designations but it looks like you have the red and black wires reversed. Also the black wire has a "Y" label on it which indicates "Yellow" for cooling. This needs to be verified at your furnace end and wiring corrected or the Y taken off or wiring corrected. You must also have the other half of the 4 to 5 wire adapter at the furnace end connected properly. Edited January 8, 2015 by larryllix Link to comment
TMR Rudy Posted January 8, 2015 Author Share Posted January 8, 2015 Sorry the labels should not be there. Interesting about the black and red wires? Link to comment
larryllix Posted January 8, 2015 Share Posted January 8, 2015 (edited) Sorry the labels should not be there. Interesting about the black and red wires? Make a diagram of each end of the cable connections and the terminal label at each end should be approximately the same. You have a 4 to 5 wire adapter in each end that makes double function usage of a single wire, just to complicate things but the end terminals should have the same colour wires. Black is usually common power = ground, but is stolen for thermostats to get a fan control wire where common is not needed for battery carryover thermostats that can steal power from the other wires to charge a carryover battery or capacitor. That is most likely why your black wire has a Y label on it and it was never removed hen the 4 to 5 wire adapter was installed. Reviewing your photo again I see the black and red are probably wired correctly but the thermostat has some odd labelling on the terminals. The top terminal appears to have "COM" on it and would be black. The second terminal has "RH" (Red for heat) but also "..HVAC Return" which seems self contradictory to it's own terminal nomenclature. Perhaps others with the 2441TH thermostat can help more. By your symptoms I would check the furnace end of the black wire closely. I believe if not connected your thermostat would display this behaviour. Do you have an AC voltmeter? Edited January 8, 2015 by larryllix Link to comment
stusviews Posted January 8, 2015 Share Posted January 8, 2015 Thermostat terminology is different. Common is actually considered the source. From there to the devices (i.e,., furnace, compressor, fan), then to thermostat and finally return (red) back to the source. Link to comment
larryllix Posted January 8, 2015 Share Posted January 8, 2015 (edited) Thermostat terminology is different. Common is actually considered the source. From there to the devices (i.e,., furnace, compressor, fan), then to thermostat and finally return (red) back to the source. The contacts in the dozen or so thermostats I have wired all have contacts from the Red wire (R, Rh, Rc) to the outputs (W,W1,W2,G,G1.G2.Y.Y1,Y2) switching the ungrounded 24vac (Live R). Switching grounded wires would be a non-standard practice and would also violate some North American electrical safety codes. The common, almost always labelled C is always the return to the 24vac transformer common and is the return to the source. The common is typically grounded at the source in the furnace to avoid stray induction and leakage voltages. Wikipedia lists the usual standards on a nice chart that match anything I have witnessed. http://en.wikipedia.org/wiki/Thermostat Here is a very nice website with descriptions, diagrams and some animations showing power flow in a thermostat system with A/C and heating contactors. http://www.how-to-wire-it.com/wire-a-thermostat.html Edited January 8, 2015 by larryllix Link to comment
stusviews Posted January 8, 2015 Share Posted January 8, 2015 I never said anything about switching the wires. It does matter which wire is connected to C and which to R. My reference was to using the term "return" for the red wire. Each "system" uses colors and words differently. For example, in line voltage, white is considered neutral and the line is black, but in DC circuits black is the common or ground. And in thermostats, the common wire is usually blue. But it's not the same common as line voltage where the neutral is also referred to as "common." It comes down to common usage Link to comment
larryllix Posted January 8, 2015 Share Posted January 8, 2015 I have just installed the second (shipped under warranty) Insteon Thermostat. I have a question, does the grey display disappear during heating cycles of the furnace. I find that when the furnace is heating and then runs the fan, the thermostat goes blank after about 30 seconds, and then once the furnace blows out heat, the thermostat turns back onto the blue screen and acts as normal. This is happening on each cycle when the temperature falls and the furnace needs to run to bring back the set temperature. Is this by design? Do you think I have another faulty thermostat? Possible temperature gauge issue with the actual furnace? Trying to figure this one out. Wiring configuration attached. These thermostats do have reputations for being sensitive to switching the relays and/or solenoids in HVAC equipment. This sounds the thermostat firmware "blows up" and then reboots itself. A voltmeter (or better, a scope) to measure the power supply R-Bk while this is happening may show you if power remains across the thermostat. if it does you have some suppression circuitry to experiment with or send the thing back. The Insteon thermostats have a reputation for this behaviour from read other users. Link to comment
stusviews Posted January 8, 2015 Share Posted January 8, 2015 Correct wiring has not yet been verified at both ends. Link to comment
paulbates Posted January 9, 2015 Share Posted January 9, 2015 (edited) Looks like an 'add a wire' device on the left providing the green and yellow wires. Have you confirmed how they are connected on the furnace side?And to Stu's point, pull the furnace cover and provide a pic of the terminals on that side including a shot of the add a wire. We're only seeing half of the equation. Edit: ....You must also have the other half of the 4 to 5 wire adapter at the furnace end connected properly. Larry covered the add-a-wire concern, Sorry Larry, missed that. I'm suspicious that the add-a-wire is at least part of the problem. I believe the answer to this is on the furnace side, nothing more can be done at the stat. If you're not comfortable opening the furnace, I would get an HVAC guy to work through this with you Edited January 9, 2015 by paulbates Link to comment
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