Venstar T1700 with Insteon 2441V Dongle wont go into ISY

[barryH]

I did an installation in a home with 65 switches all Dual Band. We had talked about Thermostats at that time and got around to it this summer. they have 4 separate air handelers for the AC system. with a separate heat pumps for heat.for the 4 thermostats and a heat only thermostat for the basement.

i replaced 4 thermostats, at a clients, with the venstar T1700. one of them i had tested prior to installing and it had recognized the 2441V insteon adapter. the 3 others now after insatlling, give me " cannot determine insteon engine" and i tried it both auto recognize and selecting 2441V. the whole house is dual band switches. there is one more stat to install and that is the one that is supposed to be linked to the I/O linc fo heat only. i dont understand how 3 stat in 3 different areas of the house wont recognize the 2441V adapter? any thoughts and advice would be greatly appreciated. i am using the venstar add a wire kits to free up one of the wires to use as common. i worked with a HVAC person.
on the one that did recognize the 2441V if you query it, sometimes gives you a com error and you get Bangs but if you change the cool set point  it takes it and the bangs clear up.
i am at a loss here please help

[stusviews]

Is the thermostat (any one) always lit? Does the thermostat correctly control both heat and cooling?

 

What is the result if you insert the "working" 2441V into a different thermostat? Can you control that thermostat from the ISY?

[hart2hart]

The adapters can be very hard to add yet work fine once linked. I have resorted to plugging an access point into an extension cord and holding it directly next to the thermostat. This works both for adding and determine if you got comm issues for regular usage.

 

Also remove from ISY if added. factory reset and re add was an old go to method. Finally link them while they are in off mode.

 

The rf from those units always appeared very weak to me so I placed an accesspoint or lamplinc within a few feet to get reliable results.