Thermostat Not Communicating

[S Garman]

I've had the TXB16 thermostat working on HS flawlessly for several years now. Then suddenly the thermostat no longer communicates with HS, neither sending status nor responding to commands. Manually setting the thermostat still works.

I've checked the wiring and all seems in order.

Does anyone have a short list of troubleshooting ideas that I can step through to see if I can get it all back on line?

Thanks

[Msekelsky]

Are you sure that your TW-523 is still good? Have you tried unplugging the control box for 30" or so and then reapplying power?

[Wadenut]

I haven't run downstairs to check, but isn't there a LED on the TXB-16 that indicates comm activity? Also on the TW-523.

[S Garman]

I've unplugged both the TXB-16 and the TW-523 for a minute and plugged in and checked again. Same result. There is an LED on the TW-523 (red) that is constantly on, but I don't see any external LED on the TXB-16.

[Msekelsky]

I believe the LED on the TXB-16 is on the inside of the control box. Does the light on the TW-523 flash when it sees any x10 traffic? Can you test the TW with anything else to rule it out as the problem?

[S Garman]

I don't have anything to test the TW-523 with, but I can see it blinking when HS tries to communicate with it. I've also opened the control box of the TXB-16 and see no lights flashing at all. Wondering now if my transformer is fried and if I need another one? Probably this is the cheapest test solution. What do you think?

[Msekelsky]

I have two TXB-15s and I can't believe they would be too awful different than what you have. In my case the status LED flashed (slowly). If you are not getting that then I think your idea of trying the transformer is a good one. Or maybe put a meter on the transformer.

[S Garman]

I took removed the transformer with the intetion of taking it to buy a replacement. Some hours later I noted that the wall unit (manual) was completely blank (no power). So I plugged in again the transformer which restored the power to the wall unit, but still no reactions from the control box. This makes me think that the transformer is fine and the control box is bad. Your opinion?

Thanks,

S Garman

[Msekelsky]

Sure sounds like it is not the transformer, but that doesn't necessarily mean the controller is bad. If you don't have it, here is a link to the manual. It has a couple of tests in there you could try. Or, on the main RCS page they have a contact link. I would try asking them what they think may be wrong.

[Wadenut]

- If the wall display backlight lights up but no LED's on on the controller, it's not the transformer. One of those LEDs is a communication indicator. It seems to me the controller must have gone south on you in that case. Are there any numbers on the display? The only other thing would be the connection between the TStat controller and the TW-523, including inside the TW itself. These can be had on Ebay for about $10. Perhaps an email to RCX for advice might also be in order. I'd had problems with my TXB-16 initially and they were very good about helping out.
- Another thought. I don't quite remember but the controller LEDs may not actually light until the stat has been initiallized by HS. Has the stat house code maybe reverted to "A" ? This needs to be configured from the wall unit.
- According to the manual there's an X10 sequence you can use to totally reset a hung txb unit: P4 On, L3 OFF, H2 ON, D1 OFF. This will set the unit to factory settings, so if it works you'll have to reconfigure the stat.

Hope something here helps.

[S Garman]

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The wall display lights up and there are no LED's on the controller. There are numbers on the display. Strangely this weekend it seems to randomly pick new set point for the AC. Sometimes 71 degrees, sometimes 80? Weird. Noticed a loose wire in wall display that I've tightened.

I manually reset the X-10 house code to J, to no effect.

With respect to your suggestion

"According to the manual there's an X10 sequence you can use to totally reset a hung txb unit: P4 On, L3 OFF, H2 ON, D1 OFF. This will set the unit to factory settings, so if it works you'll have to reconfigure the stat."

You'll have to forgive me, but I'm a bit of a novice and for me to implement that sequence, I would need a bit more guidance.

I'll take your advice and e-mail RCS to see if they have any suggestions.

Thanks for your help.

S Garman

[Msekelsky]

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"According to the manual there's an X10 sequence you can use to totally reset a hung txb unit: P4 On, L3 OFF, H2 ON, D1 OFF. This will set the unit to factory settings, so if it works you'll have to reconfigure the stat."

I think that is more to reset the wall unit, which does not seem to be your issue. OTOH it can't hurt. Got to HS, try http://homeseer:81/ctrl if you do not have a link (use your port number) and you manually send those codes. But if the controller is not sending/receiving I don't think that will work.

[S Garman]

Last night after rechecking everyting, I found a loose wire on the lower right of the wall unit. I re-attached it and checked the system again. No luck. Following advice I e-mailed RCS who has already on this weekend sent a fine and friendly reply. But by midnight, once my regular status e-mails on temperature were scheduleded to start again, it seemed that all was back in order! HomeSeer and the thermostat are now communiating find again.

So I think here the loose wire was the problem. I'll monitor it over the next weeks to see that it performs as expected. Thanks for all the support on this forum. I know that all of you are far more advanced than I am with respect to HomeSeer, and I appreciate all the ideas and feedback provided.

Kind regards,

S Garman

[Msekelsky]

I hope it was that simple or that the problem never returns!