Remote thermostat for older Amana PTAC?

kiwanda

I have a late 90s Amana PTAC (model #PTC093A35AB) in a guest room that I would like to control with a remote thermostat. I have an extra Honeywell manual thermostat (model #LC1620/T87F) with separate heat/cool controls. What I can't determine is if these units are compatible. The PTAC manual is vague on this and I can't find any literature on the T87F that answers my questions either.



Anyone have any advice on this?  I was going to replace the PTAC this summer but we've decided to keep it another year, so I'm hoping better controls will make it more useable in the space.



Thanks,



Kiwanda

kiwanda

Question about fan control still-- help?

Tracking down help from the manufacturer was a bit of a challenge. I finally spoke with a tech that confirmed this old Honeywell t-stat will be fine with the PTAC. I've got it installed and it worked fine for cooling, but sending a call for heat triggers a "faulty thermostat" diagnostic code from the PTAC board.  I worked on this for a while and think the problem is that while the t-stat turns on the fan with a call for cooling (it appears to close both Y and G for cooling) it does not on a call for heat (only closes W2 and not G). The PTAC board reads that as a failure and won't turn on the heat, since it expects the fan to be on also.



This was verified by sending a call for heat with the fan switch on the t-stat set to "on" rather than "auto." PTAC heat came on under those conditions.



So I need some way to get the Honeywell T87F (manual here http://customer.honeywell.com/techlit/pdf/69-0000s/69-0579.pdf) to close G when there's a call for heat.  It would seem a simple task, but the manual only has examples for three-wire hookups and this PTAC requires four.



thanks,



kiwanda

JStar

...

Relays can change the world.



Have the T-stat energize a relay coil that sends R to both W and G.

JStar

Picture

Hope this makes sense. USE FUSES!!!