Thermostat for variable speed blower

bobk

Greetings. In my new house I have an Amana (AMVC950905DXAB) gas furnace and Goodman A/C. I installed an ecobee thermostat last year, and since I only have 4 wires, I used the G wire for C, since the ecobee needed a C wire. The heating/cooling in the house seems uneven, so I thought I'd try leaving the fan on all the time, but of course, that means I need the G wire. I bought a cheap Honeywell thermostat and hooked it up, but "fan on" doesn't work. I think it's because I have a variable speed blower, two-stage furnace, and it needs some other kind of voltage. Is this right? If so, can anyone recommend a thermostat that will work? and doesn't need a C wire?
And what about the uneven temp in the house? Is leaving the fan on the right thing to do? Honeywell sells sensors for other rooms that communicate with the t-stat -- does anyone have experience with those?
Thanks!

mattmia2

Did you try adjusting the balancing dampers in the ductwork?

HVACNUT

Well, run a new 8 conductor thermostat wire. Why have a 2 stage furnace if you're not going to take advantage of it? Does the ecobee have W1, W2? Is it 2 stage A/C?
Or a Honeywell Pro9000WF with RedLink gateway and EIM (equipment interface module). You only need 2 wires at the thermostat. R and C. 

bobk

Thanks for your suggestions. I've done some reading and realized I'm in over my head. doesn't take much. The manual for the furnace recommends a ComfortNet CTK01A communicating thermostat. If you don't have one of those, You can select single stage thermostat with a dip switch on the motherboard, and then stage transition is on a delay -- you can select auto, or set the delays with dip switches. The blower speed should be 30% of max if continuous fan is set on the thermostat. So it should work the way I have it, with the single stage thermostat, but the continuous fan setting doesn't work. I'm beginning to think my new thermostat is defective.
Any more suggestions?
Thanks.

HVACNUT

You removed the Ecobee and replaced it with a cheap Honeywell? So now there's no Common but no need. Battery powered. If you jump R and G at the thermostat sub base, the fan should come on at 30%. If not, try the same thing at the board. 
Put the 2nd stage dip switch on auto.

bobk

Ok, thanks. I can try that. I was kinda hoping I could select fan on with the thermostat switch. that's why I replaced the ecobee -- to get back the G wire I had used for C.

unclejohn

Use the tstat that the manufacture recommends. Some variable speed fans require a "G" and a "Y" input to work properly in the cooling mode. You will also get cool to dehumidify with the right tstat.

bobk

Thanks. That sounds like the right thing to do. Unfortunately, the dang thing is pricey. The CTK04, the most recent version, is $500!

ratio

True, but if it's the communicating stat, it only needs 4 wires to operate; & the communicating stat the only way to get the highest performance out of the system…