A new 2441TH issue

[larryllix]

All connected and working. Heat, AC, and Fan control.

 

The Energy mode hasn't magically turned itself on, yet. It's probably cycled on about 40 times.

 

The surge suppressor is grounded on the same circuit as the furnace and I verified the frame of the furnace is grounded. I'm not sure why I'd add the MOV considering all leads are connected to the surge suppressor which I would assume has an MOV of some flavor.

Excellent news! Here's hoping!

[CompKing]

I am now facing a similar issue on my 2441TH.  It was working fine for the first part of cooling season, but clearly some kind of spike has changed my thermostat permanently [damage?]

 

Symptom:

I don't get "Energy Mode", but I get a mode/temperature change no matter what prior mode I am [Cool Only, Auto, Program Cool] when my AC unit finishes its cycle [causing noise]; my thermostat resets to Auto Mode and sets Heat Setpoint to 3c and Cool Setpoing to 31c.  This happens every time AC unit finishes its cycle.  I can write a program to detect this, but I don't always have a proper value of the previous mode to reset it back to.

 

Diagnosis:

To isolate the issue, I unplugged my ISY-994i and Factory Reset the 2441TH to see if the issue still happens.  Without the ISY and the 2441TH in factory defaults, the symptom still happens.

 

Attempted Solution:

I put in line on each lead on the thermostat a TVS Diode to try to isolate the voltage spikes.  This has not improved the senario, and the thermostat continues to go back to these values.

 

I believe this is not a program or a bad link on my system, but purely due to electrical noise.  I am going to try more isolation steps by doing separate 24VAC to my HVAC system from a separate transformer.  I have not yet been in contact with SmartHome.  My 2441TH unit shows "Rev 1.15" on a sticker on the wiring surface.

 

Based on this forum, I am hesitatnt to call SmartHome due to their lack of good support on this issue, though I would like to know if anyone has a unit with a more current "Rev" number which I could ask Smarthome to update.

 

Likely a replacement unit could work for me, since this problem only surfaced part way through cooling season, and was working fine prevously.

 

Thoughts?

 

http://ca.mouser.com/Search/ProductDetail.aspx?R=P6KE30A-E3/54virtualkey61370000virtualkey625-P6KE30A-E3

Edited July 23, 2014 by CompKing

[larryllix]

...

 

Attempted Solution:

I put in line on each lead on the thermostat a TVS Diode to try to isolate the voltage spikes.  This has not improved the senario, and the thermostat continues to go back to these values.

 

...

 

Likely a replacement unit could work for me, since this problem only surfaced part way through cooling season, and was working fine prevously.

 

Thoughts?

 

http://ca.mouser.com/Search/ProductDetail.aspx?R=P6KE30A-E3/54virtualkey61370000virtualkey625-P6KE30A-E3

Me thinks your TVS diode is way too low a voltage rating. This should clip about 30vdc. Your supply is likely 24vac peaking at 24 x SQRT(2) = 34v !  Yeah I have made  some of my own firecrackers when I got caught with the AC/DC thing (just the electronic portion of that!.   ) 

 

The MOV is likely doing nothing and  blown apart physically or inside.

 

This does look like a tstat hardware defect, now. A replacement should work, IMHO, but I would pass all leads through some toroid to  spike protect it. I have two 2441ZTH and they work OK but are not directly connected to anything. There is a previous thread where others have had big issues with this and IMHO it looks like this unit can't take being connected to the real world.

Edited July 23, 2014 by larryllix

[paulbates]

I appreciate this thread and remain disappointed in SH at the same time. I added a 2441TH to my HA system at about the same time that this thread started. I had random mode changes, or shifting to full on Heat with not stop. WAF went through the floor. I had similar calls with SmartHome trying to "fix" my HVAC system, which continues to have (2) 12 year old RCS X10 stats that work fairly reliably. So this thread is telling to my story.

 

SH needs to better beta market test their products. I bought a Hub 2 years ago, and it had to be replaced with one with new firmware after months. After that it’s been fine.

 

However it looks like that did not happen for the 2441TH. I really appreciate the field engineering and effort in this post, but SM hasn’t resolved the root cause. I don't want to spend this much for 2 stats to have to proceed to 'McGyver" them to get what I already have in my RCS stats plus some new features.

 

Sounds like it’s still not time to buy.  

[pgershon]

Did people ever get this figured out.  I tend to have difficulty in the winter but not the summer.  Just had housekeeper call me to say it was cold in the house - 2441 went from heat to cool mode on its own.  I know it does this.  I too am sure it relates to voltage when the furnace cycles on.

[Teken]

Did people ever get this figured out.  I tend to have difficulty in the winter but not the summer.  Just had housekeeper call me to say it was cold in the house - 2441 went from heat to cool mode on its own.  I know it does this.  I too am sure it relates to voltage when the furnace cycles on.

 

After reading this mile long thread and tracking the efforts over the last year or so. I don't believe this issue has ever been finalized on the SH / Smartlabs side. This is probably the major reason I have never installed the five Venstar TSTATS into my home.

 

Even though the very last Insteon adapter resolved all the on going traffic.

 

I am not prepared to integrate the TSTAT into my Insteon network until such time as I am 100% its rock solid. I have been testing the five units for more than two years and so far it appears solid. So, maybe next summer I will get one of the T1800 Venstars hooked up so I can finally close the HVAC loop of my integration. 

[paulbates]

The 2441TH is not a venstar designed or manufactured device. This is a case of a consumer electronics company, smartlabs, trying to back into the hvac business. The 2441THs work for many, but not for all.

 

My older hvac units triggered the same 2441TH issues noted by others... locking up and random mode changes. I sent the 2441THs back.

 

Venstar has been in the hvac business a while and makes about 25% of the stats in the us.

 

I recently installed 2 venstar t5900 wifi thermostats on the same hvac system, and they function perfectly. I since upgraded hvac systems and venstars drive the new units well too.

 

Paul

 

Sent from my iPad using Tapatalk HD

[Teken]

The 2441TH is not a venstar designed or manufactured device. This is a case of a consumer electronics company, smartlabs, trying to back into the hvac business. The 2441THs work for many, but not for all.

 

My older hvac units triggered the same 2441TH issues noted by others... locking up and random mode changes. I sent the 2441THs back.

 

Venstar has been in the hvac business a while and makes about 25% of the stats in the us.

 

I recently installed 2 venstar t5900 wifi thermostats on the same hvac system, and they function perfectly. I since upgraded hvac systems and venstars drive the new units well too.

 

Paul

 

Sent from my iPad using Tapatalk HD

 

Understood about the Venstar, the point I was making was the Insteon adapter in the past caused untold grief and massive COM issues. With the last revision of the adapter it appears this issue has been resolved.

 

For me even though it has worked correctly in an (isolated) environment not integrated into my HVAC. I am still going to be cautious about making the final hook up until my testing is all done. 

[paulbates]

Did people ever get this figured out. I tend to have difficulty in the winter but not the summer. Just had housekeeper call me to say it was cold in the house - 2441 went from heat to cool mode on its own. I know it does this. I too am sure it relates to voltage when the furnace cycles on.

Yep, most likely spikes from the gas ignitors traveling to the stat and interfering with its non filtered main board.

 

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[pgershon]

Yep, most likely spikes from the gas ignitors traveling to the stat and interfering with its non filtered main board.

 

Sent from my iPad using Tapatalk HD

So is there a working way to filter out the spikes?

[paulbates]

If you back up to post 91 in this thread, its discussed and documented. Electronics knowledge and experience is needed.

[pgershon]

If you back up to post 91 in this thread, its discussed and documented. Electronics knowledge and experience is needed.

 

I read thread 91.  Looks like he is using some kind of surge suppressor,, but no make and model is specified - just that he connects to/from it through RJ45

[pgershon]

Follow-up question- how much power is too much for the thermostat?  is a 50W 24V transformer OK

[stusviews]

Power supplies are rated for the amount of power available. That doesn't mean that any device connected to it will use that much power. So, no, a 50 watt supply is not too much and yes, it's OK to use a power supply with the rating you specified for the thermostat.

 

BTW, it's unusual for a power supply to be rated in watts. The usual rating is amperes. Is it an LED supply?

Edited November 26, 2014 by stusviews

[Brian H]

The output of the transformer could be higher than 24 volts. If it is lightly loaded.

[shannong]

I was the one who posted the workaround. It was effective but I ended up returning them and adding Zwave to my ISY. I'm now using the Zwave Tstats from 2Gig. It works but I'm not overly pleased with them.

 

If you use a surge suppressor that also has protected RJ45 "data ports" you can put it inline between your 2441TH and your HVAC control board. That was 100% effective for me in filtering out the voltage spikes on my gas heater from making the 2441TH changes modes and other issues. You could buy a dedicated Ethernet line filter but it costs just as much as the consumer grade surge protector with the data ports without any additional benefits except using up less space.

 

See the attached diagram.

 

You either need to cut up a Ethernet cable to have two ends of cable with RJ45 plugs for pigtails or be able to crimp your own plugs onto your cables. You'll have to make pigtails for the connections since the wires used for tstats is too thick to be crimped into an RJ45 plug directly.If cutting up a Ethernet cable, I'd try to get one that is at least 24AWG. Most shorties are only braided 26AWG. Your best bet is 22AWG which is usually solid strand cable, which is what I used.

 

One of my three surge suppressors wouldn't work for this. Most tstat connections need five wires. I had an older surge suppressor that was only passing four of the eight wires through the protected data ports. It was made when Fast Ethernet (100MB) was the standard for home networking stuff, and FE only uses four of the eight wires so apparently they only passed the four connections necessary for FE to save a few bucks.  Gigabit Ethernet (1000MB/1GB) uses all eight of the wires. As long as it's a recent surge suppressor you should be fine.

 

 

 

 

 

[pgershon]

Thanks for the response.  I finally hooked in a separate transformer.  I had to cut the cable from the thermostat to the HVAC.  It was a six wire cable, with 5 active for the stat.  The red was power and blue was common.  I hooked these two to the transformer but the HVAC did not seem to go on (the 2441 stat powered up fine but the heat and cool setting were not powering up the HVAC).  I phoned Smarthome, who suggested I run only the power to the transformer and run the common just to the HVAC unit.  That produced no power, and somehow, the power from the HVAC terminated.  I could not get the 2441TH to turn on connecting the wires as they had been.  I checked with a voltmeter and there was no power getting there.  Somehow either my power or common got shot as I was working on this.  I reconnected the transformer, so the red lead connects to transformer, 2441 and the HVAC red, and the blue lead connects to transformer, 2441 and the HVAC blue.  That seems to have the system running.

 

I will wait a few days and see if energy mode and/or cool cycle kicks in on its own (tends to happen infrequently, not regularly, and when it is colder than it is right now).  I have no idea what happened to the power from the HVAC itself.  I see no evidence of a wire coming loose.  

 

I am going to try this:

http://www.apc.com/resource/include/techspec_index.cfm?base_sku=pnet1gb&tab=features

Edited November 27, 2014 by pgershon

[pgershon]

So I installed the APCC surge protector, but it did not help.  I cut the cord with the 5 HVAC wires running to thermostat and spliced each end to Cat3 wire, installed an RJ-45 clip at each end, and ran through APCC surge protector.  This morning, I went back into energy mode when the ignitor went on.

 

I should add that I ran my transformer into the 24VAC return (red) and 24VAC common (blue) lines.  I needed to make a 3 way connection of the transformer to the thermostat and HVAC for both the red and blue.  In theory I should only have needed to do for the blue, but the fan was not turning on/off with the heat when the red from transformer not connected.  I think I may have blown the HVAC transformer power in the process because my system no longer works without my external transformer.

 

Anyway, I still go in/out of energy mode.

[shannong]

 

 

I should add that I ran my transformer into the 24VAC return (red) and 24VAC common (blue) lines.  I needed to make a 3 way connection of the transformer to the thermostat and HVAC for both the red and blue.  In theory I should only have needed to do for the blue, but the fan was not turning on/off with the heat when the red from transformer not connected.  I think I may have blown the HVAC transformer power in the process because my system no longer works without my external transformer.

 

Anyway, I still go in/out of energy mode.

 

That's quite surprising. Perhaps the surge suppressor in that APC isn't handling the massive spikes coming from your unit. What is the exact model of the APC suppressor?

[pgershon]

That's quite surprising. Perhaps the surge suppressor in that APC isn't handling the massive spikes coming from your unit. What is the exact model of the APC suppressor?

It is an APC PNET1GB (Personal Surge ProtectNet 1Gb Ethernet 60 V)

 

 

• Peak Current Normal Mode: 6.50 kAmps
• Peak Current Common Mode: 0.25 kAmps
• NM Surge Response Time (ns): 1 ns
• Data Line Protection: RJ45 10/100/1000 Base-T Ethernet protection
• Data Lines Protected(multi-line only): 1-8

Edited December 5, 2014 by pgershon

[pgershon]

To add to the above - and maybe success now.  

 

Made 2 changes:

 

1) There is a grounding wire on the surge protector that I had left loose.  I attached to the vent (with tape).

 

2) I changed the transformer I was using to a less powerful one (using 2 wire  1.67A output now, had been using 3 wire 2450 transformer that was rated for 50W and I believe 2 amps.

 

In any case, HVAC has cycled on and off 8 or more times in last 18 hours and no energy mode.  Had been going in and out of energy mode 3 or every 4 cycles.

 

Would love to hear people's thoughts as to what made the difference?

[Teken]

To add to the above - and maybe success now.  

 

Made 2 changes:

 

1) There is a grounding wire on the surge protector that I had left loose.  I attached to the vent (with tape).

 

2) I changed the transformer I was using to a less powerful one (using 2 wire  1.67A output now, had been using 3 wire 2450 transformer that was rated for 50W and I believe 2 amps.

 

In any case, HVAC has cycled on and off 8 or more times in last 18 hours and no energy mode.  Had been going in and out of energy mode 3 or every 4 cycles.

 

Would love to hear people's thoughts as to what made the difference?

 

Grounding is critical in any electrical system. I would have to gather this was your problem. A PSU will only provide what ever the load requires it doesn't matter how big it is.

 

That simply allows you to provide more current to the device should it require it.

[shannong]

 

 

Would love to hear people's thoughts as to what made the difference?

 

Definitely the grounding. I didn't think to ask about whether the circuit and/or our surge suppressor were properly grounded.

 

Unless the transformer was faulty, changing it wouldn't make a difference and surely not because of providing "too much" power. Under powered would be a different issue.

 

Do some more testing and let us know the results. Good luck!

[Brian H]

Transformers can also have a higher output voltage. If not loaded close to its rated current.

[stusviews]

The difference between 1.67 and 2 amps is not great enough to cause that discrepancy. But a 3-wire transformer has me wondering--which winding was used and what were the two possible voltages?