Trane 803 & XL16i Heat Pump staging

[skunkiechris]

I'm getting an XV95, XL16i heat pump, and the 803 thermostat. I understand how staging works with either the heat pump or the furnace, but not both. How does the thermostat handle what is really like four stages of heat, without being able to control four stages? (In my mind -- HP stage 1, HP stage 2, furnace stage 1, and furnace stage 2)

Will the thermostat call for stage 1 and stage 2 heat pump and never call for the furnace if the outdoor temperature is above the lock out point? And then once it goes below that point it switches to furnace? Or, if it's above the lockout point and it's running HP stage 2 and not satisfying the heat call, does it somehow know to switch to the furnace?

Thanks!

[second opinion]

I'm getting an XV95, XL16i heat pump, and the 803 thermostat. I understand how staging works with either the heat pump or the furnace, but not both. How does the thermostat handle what is really like four stages of heat, without being able to control four stages? (In my mind -- HP stage 1, HP stage 2, furnace stage 1, and furnace stage 2)

Will the thermostat call for stage 1 and stage 2 heat pump and never call for the furnace if the outdoor temperature is above the lock out point? And then once it goes below that point it switches to furnace? Or, if it's above the lockout point and it's running HP stage 2 and not satisfying the heat call, does it somehow know to switch to the furnace?

Thanks!

Your Tstat will give you 3 stages and the furnace control board will be 4th stage if needed.

[mayguy]

I would upgrade the t-stat to the Honeywell IAQ or Trane's 900 series t-stat. With that stat, you'll get a true staging for your gas heat rather than timer for 2nd stage gas.

[cmajerus]

I would upgrade the t-stat to the Honeywell IAQ or Trane's 900 series t-stat. With that stat, you'll get a true staging for your gas heat rather than timer for 2nd stage gas.

plus the IAQ is a better alternative for the installer as he doesn't need a fossil fuel kit. But if he insists on the fossil fuel kit, give him my email, I have 2 I will never install again.

[skunkiechris]

Okay -- so is this correct: With the 803, it will control switching between HP stage 1, HP stage 2, and Furnace. On a furnace call, the furnace will start out at stage 1, then, based on a timer on the furnace control board, it will jump to stage 2 if x minutes are exceeded?

If that's correct, I definitely don't like that. It would seem like if furnace stage 1 is just satisfying the heat call, and therefore staying on....after x minutes it would go to stage 2 even though it's not really required, and give a blast of hot air then shut off!

I'll talk to my installer today about switching to the 900 or IAQ...my concern is that they will never have done this before -- HP's are pretty rare around here. Is it difficult to correctly wire the 900/IAQ vs. the 803? I have read that the 900 works with the new XC95 directly, I wasn't sure how difficult it would be to make it work with the XV. Is there something else that's required to make it work? I'd like to have that information in hand just in case my installer says "Oh that's only for the new XC (or XL19i)." Does Trane provide instructions for wiring the 900 with the XV95 & XL16i heat pumps?

Thanks!

[mayguy]

If you went with the 803, then yes, the 2nd stage on the gas furnace will fire off after X amount of time on the board. The IAQ/900 will only fire it if needed.

Also with the IAQ/900, you can lock out the back up heat when you really don't need it since heat pump itself can do it by itself with a little more time.

They may seem complex, but really not hard to do as long the installer follows the install manual step by step.

[cmajerus]

I hooked up the IAQ to the 16i HP system very easily, not a very difficult job IF they read the install manual wiring diagram FROM THE CONDENSER and the IAQ. They will have issues if they follow the furnace wiring diagram for 2 stage hookup. Unless Trane has updated the wiring in the furnace install manual, it doesn't have a diagram for 1 compressor 2 stage, just 2 compressor 2 stage.

[skunkiechris]

I know the 900/IAQ are the same stat, but I need to stick with the Trane branded version due to the system rebate (which requires one Trane thermostat in each install.) I've read elsewhere on here that the XC95 has EIM built in. Is the 900 intended only for the XC? As in, will it not include the EIM necessary to hook to an XV95? And does anyone know if the Trane install guide covers this application? I'm just anticipating the confused look from my dealer and trying to be prepared for the possible "Oh no, that's for a different furnace." response!

Also, a question on the humidifier control on the 900/IAQ. Does it allow the humidity setting to be manually adjusted during heating? If so, does it place limits on it based on outside temp as not to end up with condensation in the house, like the standalone Trane automatic humidifier control?

Thanks again for all the help!

[mayguy]

I've read elsewhere on here that the XC95 has EIM built in. Is the 900 intended only for the XC? As in, will it not include the EIM necessary to hook to an XV95?

The XC95 will come with it's own t-stat with a built in EIM, for the XL900, that is the stat, and EIM.

Also, a question on the humidifier control on the 900/IAQ. Does it allow the humidity setting to be manually adjusted during heating? If so, does it place limits on it based on outside temp as not to end up with condensation in the house, like the standalone Trane automatic humidifier control?

You can have it wired with an outdoor sensor with frost guard on or off. I would suggest have that on to prevent any moister issues with wood/windows. I have it on mine and you can bump up the frost guard if you feel you need a little bit more humidity.

[skunkiechris]

Great, that answers all of my questions for today...I'm sure there will be more when this install gets rolling

Thanks!!!!