Insteon Thermostat Does Not Engage Auxillary Heat

[Tango]

I have a two floor house we just finished building in September.  It has a heat pump for both the upstairs and downstairs and, originally, had a Honeywell thermostat for each floor.  I ordered two Insteon thermostats for heat pumps (https://www.smarthome.com/insteon-2732-242-thermostat-for-heat-pump.html) from Smarthome and installed them.  They worked fine and they worked fine when I changed the setpoints through my ISY.
 

Now that we're in this cold wave, I'm finding out the auxiliary heat is not kicking in.  There are days when it won't warm up over 62° in this house now.  I talked with the HVAC contractor who installed the system with the original Honeywell thermostats.  I sent him a photo of my wiring connections to the Insteon thermostat (see attached photo) and he said it was wired properly.  Then he had the guy who did the actual work call me.  He asked if I minded swapping out the Insteon and replacing it with one of the old Honeywell thermostats.  It saw the temperature difference (between actual and set temperatures) was over 2° and engaged the auxiliary heat.  There can be a difference of 10° and the Insteon thermostats still do not turn on the auxiliary heat.

This tells me the heat pump and HVAC system is working properly, since it works with the Honeywell thermostat.  The problem is the Insteon thermostats are not turning on the aux heat.  My wiring work is in the attached photo, in case that helps.

How do I make the Insteon thermostat activate the auxiliary heat when needed?

 

[apostolakisl]

You could test the thermostat by disconectin the aux heat wire (the white wire) and running a jumper wire out from the aux terminal and the common terminal.  Close the thermostat and turn it on to heat at 90 or something.   Put a volt meter acrss the two leads and see if it is outputting 24vac.  If not, then the thermostat is not turning on aux heat.

 

You would have to call Insteon since I don't believe there is any use configuration for aux heat.

 

I suppose you could try doing a full reset on the thermostat as well.  It is in the manual.  But since there is no configuration for aux heat, I kind of doubt it would change anything.

[bipto]

If I recall correctly Insteon heat pump-capable tstats do not support dual fuel / aux source systems...

[Tango]

You could test the thermostat by disconectin the aux heat wire (the white wire) and running a jumper wire out from the aux terminal and the common terminal.  Close the thermostat and turn it on to heat at 90 or something.   Put a volt meter acrss the two leads and see if it is outputting 24vac.  If not, then the thermostat is not turning on aux heat.

 

You would have to call Insteon since I don't believe there is any use configuration for aux heat.

 

I suppose you could try doing a full reset on the thermostat as well.  It is in the manual.  But since there is no configuration for aux heat, I kind of doubt it would change anything.

 

Wouldn't the fact that the aux heat comes on with the other thermostat and not with the Insteon pretty much prove that it works if it's getting a signal?

 

I'll check this, though, and see what happens.  I'm pretty sure, though, that it's not sending any signal out.   If it is, aux heat should be on.

[Tango]

If I recall correctly Insteon heat pump-capable tstats do not support dual fuel / aux source systems...

Doesn't this pretty much make them worthless?  They're automated and you can control them - but if it goes below freezing, they're worthless?

 

Do you have any idea where I could verify this?  They do have an aux wire on them, so if they can't do aux, that connection serves no purpose.

[bipto]

Doesn't this pretty much make them worthless?  They're automated and you can control them - but if it goes below freezing, they're worthless?

 

Do you have any idea where I could verify this?  They do have an aux wire on them, so if they can't do aux, that connection serves no purpose.

Being "heat pump" compatible and "dual fuel" compatible are two different things. I scanned the manual for the Insteon and couldn't any references to dual fuel, auxiliary sources, etc...  I'm not familiar with your system, but when shopping for automated tstats for our new heat pump / propane system I considered the Insteon and had to disqualify it for this reason...

[TrojanHorse]

Tango,

Page 15 of the manual appears to show a way to test the auxiliary heat function?

In my experience insteon thermostats are not reliable. I have the 2441TH in my garage and it will occasionally indicate it is heating when it has not actually turned on the heater. Apparently due to voltage spike. Not sure if your thermostat has the same problem. I’ve created some programs to work around this but they’re really only suitable for my garage where I don’t mind temperature drops say 5°F

 

Might be worthwhile to put the Honeywell back in as a test and also to likely keep you warm!

 

 

Sent from my iPhone using Tapatalk

[Tango]

Thanks for the answers!

Okay, from what I see on Page 15 of the manual, I have to manually turn on, and off, the aux heat mode.  I'm just stunned any thermostat today would be so - well, primitive.  That's like a grad student saying, "Duh - I can't handle the coursework for this 100 level class."

Looks like I'm going to have to shell out the money for a Z-Wave - anyone have suggestions or links to good comparisons of Z-Wave thermostats?

(Meanwhile, I'm wondering if I can get Smarthome to take these two back on the grounds that lacking this feature makes them seriously outdated.)

[apostolakisl]

If you read what it says, it seems to be saying that it "instantly" activates aux heat mode.  To me, that reads as though it normally uses aux heat, it just doesn't do it "instantly'. 

 

Certainly testing that mode to see if it turns on aux heat would be a worthy endeavor, but I wouls till call Insteon support to find out if that means it otherwise doesnt use it all.

[Tango]

If you read what it says, it seems to be saying that it "instantly" activates aux heat mode.  To me, that reads as though it normally uses aux heat, it just doesn't do it "instantly'. 

 

Certainly testing that mode to see if it turns on aux heat would be a worthy endeavor, but I wouls till call Insteon support to find out if that means it otherwise doesnt use it all.

 

That's a good point.  And that's also the only reference (other than the aux wire) to aux or emergency heat anywhere in the manual.  (I searched it.)   But I will check on it.  I think two thermostats both not being able to activate the aux heat, though, indicates it's not a feature or, at least, not a default feature.

 

I'll call Insteon tomorrow - just hope I get a rep who knows enough to understand what the issue is.  Lately the Insteon reps tend to be rather ignorant of their products.

[LFMc]

Might be a bit of a jury rig, but you could use your ISY to turn on the aux heat thru an insteon switch.

 

Sent from my XT1575 using Tapatalk

[apostolakisl]

I was thinking about this.  My house has heat pumps and is controlled by these fancy proprietery Carrier Infinity thermostats.  They use a data com between all the components, not the standard 24vac on/off wires.  The main thing that puts the heat pumps into aux heat mode is the outside temp.  But a standard thermostat has no idea what the outside temp is.

 

After all, a heat pump works just fine all by itself unless the outside temp is too low, typically around freezing.

 

I suppose that a standard indoor only thermostat decides to use aux heat when after a certain period of continuous heating it fails to raise the temp.  But even in the best case scenario, you would have to wait whatever period of time it is that the algorithm uses as the cutoff.

 

A relatively simple and perhaps the best solution would be to use an outdoor thermostat that closes a switch combining the standard heat mode wire with the aux mode wire.  So, for example, if it is below 32 degrees outside, as soon as the compressor turns on, the aux heat also turns on.  Above 32, only the heat pump turns on.

 

Unfortunately, it does not appear that turning on Aux heat is a command that can be sent via Insteon/ISY.  Otherwise, you could just program your ISY to do it for you (assuming you have the weather module).

 

EDIT:  I have read that a common thermostat protocol is to use aux heat when the set temp is more than 2 degrees from actual.  That seems like a very poor choice.  Anyone who switches back and forth between an occupied setting and an unoccupied would have the aux heat come on every single time it switches from unoccupied to occupied regardless of the ability of the heat pump to do the job by itself.  That very much defeats the efficiency of a heat pump and the efficiency of having an unoccupied/occupied setting.

 

EDIT 2:  Something like this https://www.newegg.com/Product/Product.aspx?Item=9SIA2SX38G4233&ignorebbr=1&nm_mc=KNC-GoogleMKP-PC&cm_mmc=KNC-GoogleMKP-PC-_-pla-_-HVAC+Controls-_-9SIA2SX38G4233&gclid=Cj0KCQiAvrfSBRC2ARIsAFumcm82D0AC39lEWkRsAcpykWBcLbaMYQFEe9SL5KvL8276IkBUNRHj0_EaAoy_EALw_wcB&gclsrc=aw.ds installed with the temp sensor run outside could be used to close a connection between the standard heat wire and the aux heat wire.  With this installed, you would disconnect the aux heat wire from the thermostat so that aux heat would instantly and only turn on when calling for heat and outdoor temp is below your preset number.

 

EDIT 3:  This is a descent article on aux heat.  https://nest.com/support/article/What-is-Heat-Pump-Balance It seems that Nest has really put in some fancy algorithms for deciding when to use aux heat.  Still, if it is in the 20's outside, you are pretty much going to need aux heat no matter what.

[Tango]

I called Insteon customer service today.  In all honesty, that's a waste of time.  At one point you could call and talk to people who knew the components of Insteon systems and could answer most questions easily.  What I got is what I'm used to getting now: People who do not fully understand the situation and need background to the issues explained to them.  Then they put you on hold and look up information and come back and essentially give you scripted or otherwise limited answers.  In short, they're pretty sure that the Insteon thermostat can NOT activate the aux heat automatically.  It must be done manually.  Basically I find I'm talking to people who have a poorer understanding of any particular product than I do and yet they're supposed to know enough to answer my questions - rather than me explaining everything to them.

 

In short, they're pretty sure that the Insteon thermostats can't automatically engage aux heat.  It has to be done manually - but he's going to check and call me back in a few days with a more definitive answer.

 

So I called Smarthome.  My position is that pretty much any thermostat in 2017 (when I bought my two) can turn on the aux heat as needed, without the need to activate or deactivate it manually.  This is the kind of feature needed in a heat pump thermostat to make it dependable and useable.  (What if, for instance, you're caring for an elderly or ill person in the house and need the temperature to be kept up above, say, 70°?)  I asked about returning my two thermostats.  They said it had been 95 or more days and they could not do that.  I pointed out that the thermostats are defective by design.  This issue is not the kind of thing you check in research now days because it's included in pretty much every thermostat on the market and it has the "AUX HEAT" wire, which implies it can handle it.  I pointed out this is like going to buy a new car, seeing 'R' on the gear shift and thinking, "Okay, it has all the gears," and not feeling a need to test it because that's a market expectation that a new car can go in reverse.  This is essentially a feature standard in today's thermostats, so Insteon leaving it out is less than competent.  It means the thermostat is less than adequate.

 

I also pointed out that if I had bought it just before this extreme cold wave, I'd know, quickly, it was an issue, but it took this long to find the problem because it didn't show until the system is in extreme conditions.  The guy on the phone said he'd see what he could do in talking to the next level up about this.  Of course, neither Insteon or Smarthome support (are they both the same?) let me talk to someone the next level up.

 

This weakness, and having to fight to return it because of this has really soured me on Insteon.  While I have a number of Insteon light controllers I'm planning on installing that I can't return at this point, in the future I am extremely unlikely to use Insteon.  If they refuse the return, I can say I will definitely avoid Insteon in the future - unless they are the only company making a particular type of product.

[bipto]

Not to imply defense of either the product or the company, but I'm afraid the extent of their responsibility here is that the specs do not explicitly state, contrary to consumer expectations, that this device is NOT dual fuel capable.  It's a weak argument, but it may be your best angle, IMO.

 

Heat pump support implies only that the thermostat is capable of controlling the compressor reversing valve to switch between heating and cooling modes; engaging a secondary heat source at a specified temp where the compressor is no longer efficient is usually a separate feature over and above. Many manufacturers offer heat pump-only models, reserving dual fuel capability for higher-end offerings.  This is true with my choice of Venstar, where some research was required to select a model (T1900) that was both heat pump and dual fuel capable... 

 

Just my $ .02 offered for your consideration.  Best of luck.

[paulbates]

I went through something similar 4 years ago with the non heat pump version. It was fine when there were only a few cycles a day, but then in the cold of winter, tt wouldn't function right with my furnace (locked up from igniters, long story).

 

I nicely, but firmly, said "I know its past the 30 days, but there was no way for me to know this", then asked how do I get an RMA for that?  I got the party line: "you have to wait till after we receive it back before we refund" blah-blah-blah, but I did get everything refunded. 

 

Another thing that works is "if you were me in this situation what you want". Hard to wiggle out of that one

 

Paul

[apostolakisl]

Again, thinking about this, it sure would be nice if the thermostat had the aux heat activation as a "mode" that you could set through ISY.  Then you could write algorithms in your programs to only use aux heat when it made most sense.

 

However, there is a way to do it using an iolinc.

 

Disconnect your aux heat wire from the thermostat.  Connect that wire to one pole of the iolinc NO relay.  Then connect a jumper wire from the stage one compressor lead to the other pole of the NO relay (leaving that wire attached to the thermostat).

 

With that wiring setup, if the iolinc is on, then aux heat will engage simultaneous to the compressor.

 

Then you have to also have the weather module (or some other thing that sets a variable on your ISY to the outside temp).

 

If

outside temp is <25

Then

turn iolinc on

Else

turn iolinc off

 

You can get more complicated with it as well, combining various outdoor temps with acutal indoor temps and desired indoor temps.  Basically, create an algorithm like Nest uses.

[Brian H]

It looks like that model maybe discontinued.

As it is marked "Product Is Unavailable"

https://www.smarthome.com/insteon-2732-242-thermostat-for-heat-pump.html

[apostolakisl]

It looks like that model maybe discontinued.

As it is marked "Product Is Unavailable"

https://www.smarthome.com/insteon-2732-242-thermostat-for-heat-pump.html

If you look at review number 2, there is also the same exact concern with the aux heat.

[Tango]

A few more thoughts:

1. It looks like there are two packs of the item still there.  And "Unavailable" may simply mean they don't have any in stock.  It's still advertised on the Insteon page.

 

2. Using an I/O linc to work with a thermostat is possible, yes, but that also means a big box on the wall near the thermostat and the need for an AC plug or an extension wire to power it.  We've gone out of our way to create a look and feel and atmosphere for our house and the technology is hidden wherever possible (other than in the garage).  By the time I pay for an IO linc for two thermostats, I might as well just buy Z-Wave and have a good thermostat.  True, it's more than just two IO Lincs, but when you consider the extra effort in setting them up and finding a way to make them look decent, I'm going for the Z-Wave thermostats.  The question is whether Smarthome will let me return them for a full refund or not.  (If they give me a full refund, I'll buy the Z-Wave thermostats from them, if not, I'll keep pissing and moaning to them and buy the Z-Wave elsewhere.)

3. Here's a point that bugs me, and most on this forum will get this, since, if you're here, you can do enough programming to understand simple if...then logic.  You can turn on aux heat manually by pressing two buttons simultaneously.  That means somewhere in the firmware is code that has an if statement saying:
 

if (button_1 pressed) and (button_2 pressed):
   activate (aux_heat)
endif

The buttons are not hardwired to the aux heat line.  That means that in the firmware's main loop, it would be easy to have something like this:
 

if (heat is on):
   if (use_aux_heat == true):
      if (actual_temp < set_temp -2):
         activate(aux_heat)
      else:
         deactivate(aux_heat)
      endif
   endif
endif

That would allow a mode, as apostolakisl suggests (did I tag him properly?) that would let the ISY (or any other device) to specify to use or not use the aux heat.

I'm just stunned this isn't in the code.  I'm sure the product has been out long enough for them to have had other complaints about it.  Hell, if they gave me an NDA to sign and the code base, I'd add it myself.  (Assuming I had whatever it needs to compile whatever language they're using.) 

I keep wondering if overlooking this issue is related to Insteon being based in Irvine, CA, in sunny SoCal, where temperatures more than 40° or 50° below the desired house temperature are unheard of.  Is it possible the entire staff is so used to sun and warmth that they just never thought about dealing with winter?

[apostolakisl]

A few more thoughts:

 

1. It looks like there are two packs of the item still there.  And "Unavailable" may simply mean they don't have any in stock.  It's still advertised on the Insteon page.

 

2. Using an I/O linc to work with a thermostat is possible, yes, but that also means a big box on the wall near the thermostat and the need for an AC plug or an extension wire to power it.  We've gone out of our way to create a look and feel and atmosphere for our house and the technology is hidden wherever possible (other than in the garage).  By the time I pay for an IO linc for two thermostats, I might as well just buy Z-Wave and have a good thermostat.  True, it's more than just two IO Lincs, but when you consider the extra effort in setting them up and finding a way to make them look decent, I'm going for the Z-Wave thermostats.  The question is whether Smarthome will let me return them for a full refund or not.  (If they give me a full refund, I'll buy the Z-Wave thermostats from them, if not, I'll keep pissing and moaning to them and buy the Z-Wave elsewhere.)

 

3. Here's a point that bugs me, and most on this forum will get this, since, if you're here, you can do enough programming to understand simple if...then logic.  You can turn on aux heat manually by pressing two buttons simultaneously.  That means somewhere in the firmware is code that has an if statement saying:

 

if (button_1 pressed) and (button_2 pressed):
   activate (aux_heat)
endif

The buttons are not hardwired to the aux heat line.  That means that in the firmware's main loop, it would be easy to have something like this:

 

if (heat is on):
   if (use_aux_heat == true):
      if (actual_temp < set_temp -2):
         activate(aux_heat)
      else:
         deactivate(aux_heat)
      endif
   endif
endif

That would allow a mode, as apostolakisl suggests (did I tag him properly?) that would let the ISY (or any other device) to specify to use or not use the aux heat.

 

I'm just stunned this isn't in the code.  I'm sure the product has been out long enough for them to have had other complaints about it.  Hell, if they gave me an NDA to sign and the code base, I'd add it myself.  (Assuming I had whatever it needs to compile whatever language they're using.) 

 

I keep wondering if overlooking this issue is related to Insteon being based in Irvine, CA, in sunny SoCal, where temperatures more than 40° or 50° below the desired house temperature are unheard of.  Is it possible the entire staff is so used to sun and warmth that they just never thought about dealing with winter?

I agree, it shoudl be quite easy for them to include an algorithm for triggering aux heat.

 

Regarding IOlinc.  It wouldn't be mounted next to the thermostat, it would be mounted next to the hvac unit iteslf.  By code, their should be a 120vac outlet there and all the thermostat wires are of course right there.  I would expect a 5 minute install.

 

If I were to put the logic into the thermostat and didn't have ext temp available, I would use the following.

 

IF

mode = heat

and

actual temp more than 2 degrees lower than set temp

and

current run time > 30 minutes

 

Then 

activate aux heat

 

The point being, you don't want aux heat to kick on with just a 2 degree less than set.  That would trigger aux heat every single time you go from unoccupied to occupied (assuming your occupied is more than 2 degrees higher than unoccupied).

 

Personally, I would prefer to have ISY control aux heat over any algorithm built into the thermostat (unless the thermostat has access to ext temp).  Nest algorithm does this because it knows where you are on the planet and it gets the weather forecast.

[Tango]

I agree, it shoudl be quite easy for them to include an algorithm for triggering aux heat.

 

Regarding IOlinc.  It wouldn't be mounted next to the thermostat, it would be mounted next to the hvac unit iteslf.  By code, their should be a 120vac outlet there and all the thermostat wires are of course right there.  I would expect a 5 minute install.

 

If I were to put the logic into the thermostat and didn't have ext temp available, I would use the following.

 

IF

mode = heat

and

actual temp more than 2 degrees lower than set temp

and

current run time > 30 minutes

 

Then 

activate aux heat

 

The point being, you don't want aux heat to kick on with just a 2 degree less than set.  That would trigger aux heat every single time you go from unoccupied to occupied (assuming your occupied is more than 2 degrees higher than unoccupied).

 

Personally, I would prefer to have ISY control aux heat over any algorithm built into the thermostat (unless the thermostat has access to ext temp).  Nest algorithm does this because it knows where you are on the planet and it gets the weather forecast.

 

Some very good points.  I had not thought of putting it by the system itself.  (If you said to do so in your first post, I must have missed it while thinking about other details.)

 

The normal 2° limit is why I was bringing my thermostats up one degree at a time in the mornings so it wouldn't need aux heat.  I can see your reasoning to check for run time.  I've had to disconnect my Insteon thermostats for now just so we can stay warm, so I can't access them.  Do they have a way to determine how long they've been heating?  That would work well.  At that point it's a choice between fewer components or the extra level of control that provides.

 

I'm rather disappointed in the IO Linc, too, I must say.  It seems to me it wouldn't cost much to make a link that has inputs for more than one sensor and more than one relay output.  I have Arduino and Raspberrry Pi kits here that I ordered when on sale in the summer.  I have not been able to spend much time hacking or working on electronics in a long time and I'm really looking foward to using these two devices.  I am already thinking that I'd like to make an Arduino system that works with either Insteon or Z-Wave that would have multiple outputs and sensor inputs.  It's likely someone's already done that, though.  If so, that makes it easier for me!

[apostolakisl]

Some very good points.  I had not thought of putting it by the system itself.  (If you said to do so in your first post, I must have missed it while thinking about other details.)

 

The normal 2° limit is why I was bringing my thermostats up one degree at a time in the mornings so it wouldn't need aux heat.  I can see your reasoning to check for run time.  I've had to disconnect my Insteon thermostats for now just so we can stay warm, so I can't access them.  Do they have a way to determine how long they've been heating?  That would work well.  At that point it's a choice between fewer components or the extra level of control that provides.

 

I'm rather disappointed in the IO Linc, too, I must say.  It seems to me it wouldn't cost much to make a link that has inputs for more than one sensor and more than one relay output.  I have Arduino and Raspberrry Pi kits here that I ordered when on sale in the summer.  I have not been able to spend much time hacking or working on electronics in a long time and I'm really looking foward to using these two devices.  I am already thinking that I'd like to make an Arduino system that works with either Insteon or Z-Wave that would have multiple outputs and sensor inputs.  It's likely someone's already done that, though.  If so, that makes it easier for me!

 

You didn't miss it, I never posted it that you would install it next to the air handler.

 

Using ISY programs to do run time would be

 

If

control hvac heat switched on

and

control hvac heat not switched off

Then

repeat every 1 minute

$hvac.heat.runtime  =+1

Else

$hvac.heat.runtime  = 0

 

Then you use that variable in your program at >30 or whatever you want.

 

 

Regarding IO linc alternatives.  I use CAI webcontrol board and an 8 relay board add on.  io_guy wrote a node server for webcontrol board so it can work natively in ISY, though you can also use the network module to control it.  It would cost only about $50 to have 8 relays.  Though you also need an ethernet connection for the webcontrol board which may or may not be easy.  If it is hard, you can get a wifi to ethernet adapter.

[Tango]

apostolakisl:

 

I'm giving this extra consideration.  Alternatives to IO Linc is a good idea, I'm going to look into those.  Also, I'm thinking, now, of looking into a parallel solution.  I would think it would be possible to have two devices connected to the aux heat line (it may require a diode or two or a few other components), so each one can pull that line high if needed.  Then I could use a thermostat that is set up to do all it should, but the IO Linc (or equivalent) would be a backup and would also watch the time.  That way, for instance, if the temp drops 2° and the system is just not bringing it back up (like now, when it's 10° outside!), the IO Linc could still kick in with aux heat - kind of like a failsafe.

 

At this point the one thing I am sure of is that unless Insteon publishes a firmware update to fix this issue, I will not be using Insteon thermostats and will likely never use them again.  (And, considering how often my Insteon thermostats apparently missed communications to change the thermostat set temp, I'm thinking of gradually moving as far from Insteon as I can.)

[apostolakisl]

apostolakisl:

 

I'm giving this extra consideration.  Alternatives to IO Linc is a good idea, I'm going to look into those.  Also, I'm thinking, now, of looking into a parallel solution.  I would think it would be possible to have two devices connected to the aux heat line (it may require a diode or two or a few other components), so each one can pull that line high if needed.  Then I could use a thermostat that is set up to do all it should, but the IO Linc (or equivalent) would be a backup and would also watch the time.  That way, for instance, if the temp drops 2° and the system is just not bringing it back up (like now, when it's 10° outside!), the IO Linc could still kick in with aux heat - kind of like a failsafe.

 

At this point the one thing I am sure of is that unless Insteon publishes a firmware update to fix this issue, I will not be using Insteon thermostats and will likely never use them again.  (And, considering how often my Insteon thermostats apparently missed communications to change the thermostat set temp, I'm thinking of gradually moving as far from Insteon as I can.)

 

I was just looking at wifi relays.  Started another thread.  If indeed those are what I think they are, then it would be very cheap and easy to have ISY (with network module) control your aux heat.

 

If it were me, I would have algorithms like this.  $hvac.het.runtime would be a state variable.

 

If

($hvac.heat.runtime >30

and

outsidetemp < 40)

or

($hvac.heat.runtime >20

and

outsidetemp < 30)

or

($hvac.heat.runtime >10

and

outsidetemp < 20)

or

($hvac.heat.runtime >0

and

outsidetemp < 10)

 

Then

turn on aux heat

 

Else 

turn off aux heat

 

 

I'm a bit surprised you thermostats are missing commands.  Do you have a dual band device nearby?  That has not been a problem for me.

[Tango]

At first I had the Insteon modem on a power strip, but I moved it so it was on a breaker where I didn't have anything like a computer or TV or anything - commands are still being missed.  What's odd is it seems like it's commands sent in the morning.  In the evening I step down the set temp by a degree every hour or two over time.  In the morning I step it up in the same way.  Late at night, before I go to bed (I'm a night person), I check and things are set where they should be.

But in the morning, every morning when I get up, either the cool setpoint or heat setpoint is not where it should be.  It's always missing at least one if not more commands each morning - but never at night!