5 Button Comfort Control Wiring to Bedroom

[Bill Brown]

We have a problem in that the 5 button Comfort Control unit in the bedroom will not go to the "Furnace" mode.  It used to.  I have reset the control, but still no furnace mode from the rear controller.  I have switched controllers with the one from the living room, and it too will not go to the furnace mode.  So I assume there is a problem with the wiring to the bedroom Comfort Control Unit.  Any suggestions on where to look so I can trace the wiring?  I did contact Roger Burke regarding the Hydro-Hot as I thought there may be a problem from there, however, he indicated it is not something he  has encountered.
Thanks.
Bill & Nova Brown
06 Monterey, Laguna IV
02 GMC Envoy

[Ken Buck]

Is it possible that you have a 3 heat pump system and you're on the wrong unit? My rear thermostat has units 2 and 3 controlled by the one thermostat and one number, (I don't remember which) has no furnace control. It has Fan Only, Cool, Heat Pump and Off. Incidentally that is also the roof heat pump unit that doesn't operate when the dryer is on to avoid power overload.

Ken

[JimDyer]

If the control unit is not displaying the furnace option it generally means that there is a problem with the control board in the AC unit. You can pull the board and trade it with the front one - if the problem follows the control board you can then either repair or replace the control board.  

You only need to pull the offending board and then hand-carry it to the front and connect it where the one that controls your front thermostat is-- you don't actually need to pull out the front one.  There is one of the control boards for each zone, but if you only have two thermostats, you need to get to the one that controls the front thermostat. You can Google and get a downloadable manual for the Comfort Control unit, it explains the system very well.

[Edward Buker]

The heat control is usually a make or break contact (physical or electrical) so once you figure out which two wires are involved you should be able to manually contact them together. Using the color code for the wires you should be able check to verify that the same color code exists at the furnace. I am thinking that the thermostat wiring would go to the Hydro Hot and the Hydo Hot would control the firing of the zone and fan control. Sometimes the wiring is non stranded and prone to break at the connection point. Not sure if Beaver used stranded wire. You could take an ohm meter and connect one probe to the thermostat wire and one to the other end at the Hydro Hot using a long extension wire to verify continuity to rule that problem in or out. You should be able to fire up the zone at the Hydro Hot by jumpering the thermostat input wiring there. The Hydro Hot service manual should tell you how to test a zone at the unit itself. Hope this helps.

Later Ed

[Bill Brown]

We have a two heat pump/hydrohot system.  So will down load the comfort control manual, then check the control boards and hope that solves the problem.  The first time I encountered this problem, I reset the thermostat by disconnecting the cable from the back of the stat and plugged it back in.  The stat seemed to work, once.  Have not been able to get it to recognize the 3rd zone or furnace since.  
Thanks for suggestions.  
WM
06 Monterey