Trane XV80 Variable Speed 2-stage Furnace

[GeorgeM]

I have had 3 dealers come out to give me estimates on 2 new systems. I have also called the local Trane distributor ... it seems that I can easily get 4 different answers to most of my question - when in fact ONLY one answer should be correct. So ... I am still in search of the 'correct' answer.

XV80 Furnace ... Thermostat ... Variable Speed .... 2-stage ... XL14i AC

I basically understand how the 2-stage furnace operates when a single stage thermostat is used ... 1st stage heating is used, if the temperature set pont is not obtained within XX minutes, stage 2 kicks in.

Now ... what if I have a 2-stage thermostat (say the Trane one - XL800) ... do I get additional function and features for 2-stage operation??

If I do use a 2-stage thermostat, will my existing 4-wire system handle it? Or is an additional wire needed for the 2nd stage heating in this case.

What about variable speed? Half the answers said that they dont know if the variable speed still works with an existing OLD thermostat ... the other half stated that I would lose the variable speed feature, but they don't know why. Some also said I can use my 4-wire system with the XL800 thermostat and have proper variable speed operation and 2-stage operation.

And another says that I can use the XL800 that has the humidity sensor and have complete humidity via the variable speed fan.

And exactly how does the variable speed work and what does it buy me? One says is is just a marketing gimmick and does nothing. One says I can get total humidity control. One says that it just ramps up the speed and that it only is variable during the ramp-up. The other didn't know.

So ... does anyone REALLY know the answers to the above?

1) 2-stage thermostat needed and what does it buy me
2) Existing 4-wire system for the new thermostat
3) Variable speed feature loss without a new Trane thermostat
4) Variable speed operation
5) Is the XX time for 2nd stage cut-in adjustable

It is amazing that 4 Trane "expert" dealers and distributors do not know how the system works. It sure doesn't give me a lot of confidence in finding a competent installer.

Oh .. and why not ask Trane? I sent them 3 "contact us" emails ... and finally found a phone number where someone will be getting back to me. So far I am still waiting and waiting.

Thanks .... George

[BaldLoonie]

Typical

I have that furnace. I just put on a Vision Pro IAQ. Best possible control for that furnace.

With a 2 stage stat, high & low fire is dictated by how much heat the house needs. Long run periods on quiet low fire are possible with 2 stage stat making for an extremely comfy interior on a cold morning out. If high is needed, the stat ramps it up til it feels low can handle it then drops back down. On some Tranes the timer is adjustable but still far from the control & comfort of a good 2 stage stat.

The other advantage with the VS blower is control of the blower for dehumidfication. Mine is set to run slightly more air than normal when it is not humid. When the IAQ finds humidity above my setpoint, it slows the blower to less than normal speed to really suck out the juice. I can tell just by looking at the water coming out of the drain that it makes a difference. Trane does have Comfort R, a slow ramp up of the blower in cooling mode. 2 drawbacks: slow ramp reduces cooling in dry weather when not needed. Also does nothing to help humidity in hot weather when the unit is running constantly not cycling. Leaving that feature off and using dehumidify on demand is best. The Trane stats can't do this.

The IAQ stat will also control a humidifer, air cleaner, heat/energy recovery ventilator, fresh air control, etc.

[mayguy]

Now ... what if I have a 2-stage thermostat (say the Trane one - XL800) ... do I get additional function and features for 2-stage operation??

If I do use a 2-stage thermostat, will my existing 4-wire system handle it? Or is an additional wire needed for the 2nd stage heating in this case.

4 wires is not going to be enough for a two state t-stat. Two more wire will be needed, or use the Honeywell IAQ t-stat, and that only uses 3 wires.

What about variable speed? Half the answers said that they dont know if the variable speed still works with an existing OLD thermostat ... the other half stated that I would lose the variable speed feature, but they don't know why.

Trane variable speed will work on any t-stat

Some also said I can use my 4-wire system with the XL800 thermostat and have proper variable speed operation and 2-stage operation

You could use the 4 wires, but you are going on timer for 2nd stage heating.

Wire below
1-Power
2-Heating 1st stage
3-Cooling
4-Fan

Will need 5th wire for 2nd stage heating.
Should have 6th wire for Common, if you don't want to use battery on the t-stat all the time.
7th wire is suggested if you upgrade to 2 stage cooling.

But if you/they are not able to pull new wire, that's where the IAQ comes into the game.

And another says that I can use the XL800 that has the humidity sensor and have complete humidity via the variable speed fan.

That t-stat does have a humidity control, but has NO control of the blower's speed. it just "Overcools" the space up to 3˚. IAQ t-stat will slow down the blower if the home is over set point of % humidity, and the IAQ will then overcool the home if the humidity is 5% over set point.

And exactly how does the variable speed work and what does it buy me? One says is is just a marketing gimmick and does nothing. One says I can get total humidity control. One says that it just ramps up the speed and that it only is variable during the ramp-up. The other didn't know.

Variable speed got a few things that you can gain.
- Fan "ON" mode, the blower is very quiet, and soft air flow for winter time comfort, also if up have media air filter system. the air is being filtered all times.

- Blower will be easy matched with your cooling Tonnage of system, and moves the right amount of air.

- Blower can be slowed down when it's tied to a humidistat to help dry out the home in the summer.

- Quiet ramping up to speed, and slow down to speed or off.

- Uses less power.

1) 2-stage thermostat needed and what does it buy me

Comfort! Longer run times lead to comfort in the home.

2) Existing 4-wire system for the new thermostat

You will only get single stage heating, and use timer for 2nd stage.

3) Variable speed feature loss without a new Trane thermostat

Kinda, just loose the slower blower for humidity control

4) Variable speed operation

Quiet, comfort and lower power bill.

5) Is the XX time for 2nd stage cut-in adjustable

Yes, up to 15 min max.

[GeorgeM]

Well thank you for your responses. I will check out your recommendations and see if I have any other questions. I really do thank you for taking the time to respond.

Now ... can you fix the DSS problem on my downstairs 11 year old A/C that just started 1 month ago?

George

[Mstrav]

1) I have this unit in my house and its great (not installed by me, but I made a few changes to the system )

2) anybody selling you a new system sure as hell better include a new stat, and yes with 2-stages even if they need to pull in a new wire.

3) have you thought about american standard? its has a little dif warranty and a dif top on the condensor, but it is another option for you and no, you can not buy it at home depot!!

4) variable speed is the only way to go


if you tell me the tonages I can cross the model numbers for you, also would need furnace btu and what refrigerant r-22 or 410a

matt

[allstar08]

4 wires is not going to be enough for a two state t-stat. Two more wire will be needed, or use the Honeywell IAQ t-stat, and that only uses 3 wires.




Trane variable speed will work on any t-stat

You could use the 4 wires, but you are going on timer for 2nd stage heating.

Wire below
1-Power
2-Heating 1st stage
3-Cooling
4-Fan

Will need 5th wire for 2nd stage heating.
Should have 6th wire for Common, if you don't want to use battery on the t-stat all the time.
7th wire is suggested if you upgrade to 2 stage cooling.

But if you/they are not able to pull new wire, that's where the IAQ comes into the game.


That t-stat does have a humidity control, but has NO control of the blower's speed. it just "Overcools" the space up to 3?. IAQ t-stat will slow down the blower if the home is over set point of % humidity, and the IAQ will then overcool the home if the humidity is 5% over set point.



Variable speed got a few things that you can gain.
- Fan "ON" mode, the blower is very quiet, and soft air flow for winter time comfort, also if up have media air filter system. the air is being filtered all times.

- Blower will be easy matched with your cooling Tonnage of system, and moves the right amount of air.

- Blower can be slowed down when it's tied to a humidistat to help dry out the home in the summer.

- Quiet ramping up to speed, and slow down to speed or off.

- Uses less power.




Comfort! Longer run times lead to comfort in the home.


You will only get single stage heating, and use timer for 2nd stage.


Kinda, just loose the slower blower for humidity control


Quiet, comfort and lower power bill.


Yes, up to 15 min max.

This is probably the best explanation I have ever seen. Awesome

Ditto! that

[GeorgeM]

1) I have this unit in my house and its great (not installed by me, but I made a few changes to the system )

2) anybody selling you a new system sure as hell better include a new stat, and yes with 2-stages even if they need to pull in a new wire.

3) have you thought about american standard? its has a little dif warranty and a dif top on the condensor, but it is another option for you and no, you can not buy it at home depot!!

4) variable speed is the only way to go


if you tell me the tonages I can cross the model numbers for you, also would need furnace btu and what refrigerant r-22 or 410a

matt

I have thought about American Standard ... I'll probably get a quote or two from some of their dealers too. But I like the 10 year parts warranty that comes standard with the Trane ... gotta figure that is worth some extra $$$.

I am potentially looking at two systems ... a 3T for upstairs (originally was 2.5T and not cutting it), and a 2T for downstairs. The downstairs unit works fine, except for the recent DSS ... and I am hesistant to put a lot of money into an 11 year old Janitrol. My electric bills have gone up considerably (in kwHour usage) over the past 2 years, and to me it is obvious that the upstairs unit is the one sucking up the power. I was holding off on replacing it (it was checked out thoroughly 2 years ago and given a good bill of health -- but weakening) since I was not all that hot on R410a a couple of years ago. Upstairs is 1600 square feet and downstairs 1200. Downstairs always was cool and upstairs always felt much warmer. Between the hot attic, the 2-1/2 car garage under the upstairs bedroom, the many window with full sun exposure, and the rising heat from the 1st floor, those hot Austin Texas days were a challenge for the upstairs unit.

Amana is another option (high-end Goodman), but I am leaning heavily towards the Trane or American Standard.

I am not 100% behind R410a, but at this time it appears to be a better option than R-22. I was hoping by now a direct drop in replacement for R-22 would have hit the market, but alas it hasn't.

The matching furnace was the 060 for the 2T unit and 080 for the 3T.

Re:the theromstat ... the 2nd floor one is easy to pull a new wire .... the downstairs one will be quite a challenge. I'll definitely go for a new thermostat for the upstairs.

Thanks for the feedback.

[mayguy]

This is probably the best explanation I have ever seen. Awesome

Ditto! that

Glad to hear that it was the best! :-)

[mayguy]

But I like the 10 year parts warranty that comes standard with the Trane ... gotta figure that is worth some extra $$$.

Don't be afraid to get the 10 year labor warranity on any equipment.. These equipment are higher tech, main the board and motor.

The matching furnace was the 060 for the 2T unit and 080 for the 3T.

The 060 can take up to 3ton. No point of having a higher BTU furnace for upstairs.

Re:the theromstat ... the 2nd floor one is easy to pull a new wire .... the downstairs one will be quite a challenge. I'll definitely go for a new thermostat for the upstairs.

Do the IAQ, then you got the best of everything, and no new wire will be needed, and you got the humidity control to slow down the blower if the humidity rises in the home.

Thanks for the feedback.[/QUOTE]

[Mstrav]

if you get american standard just get the 10 year p&l warranty, the control boards are not cheap and you are covered for 10 years, a little preventive maintenace and filters and the rest cost you nothing and you have comfort, better air quality and the main thing, lower bills which saves you $$$ every month in cooling and heating season.

get them both with new t-stats, heck they can put a remote sensor downstairs that only needs 2 wires, and add another new wire by the t-stat upstairs where you program it, it wont read temp upstairs, that is just where you program it, and it will work perfect for you and wont have to cut up the drywall for a wire. You can also have them add a sensor outside in the eves which will display outside temp at the t-stat, this is good for the wife and kids so they no what the day is looking like for clothes to wear before walking outside.

check with your power, gas and city for rebates which is free $$$ back to you.

make sure they evaluate the ductwork as well, you mentioned up sizing one of your systems, so make sure the return size is adressed by them and put in writing what it needs!

as for r-22 or 410a it is still flip a coin in the 14 seer equipment. if the price is the same and lin-sets are good, then go 410a.


good luck,

matt

[GeorgeM]

Just as a follow-up on Trane's official response ...

"Oh .. and why not ask Trane? I sent them 3 "contact us" emails ... and finally found a phone number where someone will be getting back to me. So far I am still waiting and waiting."

Well ... it is Monday PM and I still have yet to hear from them on 3 'contact us" emails and a promised call back. The gal on the phone assured me that someone from Trane would call me back within 24 hours (last Friday AM).

I am very thankful for the info that I received from this forum ... I did receive answers to just about all of the questions that I had. But now I have such a bad taste in my mouth from Trane's complete lack of promised response that I serously doubt any response from them when and if it is really needed.

To me it seems like another company not caring about customers anymore. The company doesn't care and the Trane dealers are ignorant on Trane's products. Simply unbelievable.

Trane may have good products, but their customer service group is dismal with nothing but false promises. What a way to lose potential sales.

[jefferyb]

4 wires is not going to be enough for a two state t-stat. Two more wire will be needed, or use the Honeywell IAQ t-stat, and that only uses 3 wires.




Trane variable speed will work on any t-stat

You could use the 4 wires, but you are going on timer for 2nd stage heating.

Wire below
1-Power
2-Heating 1st stage
3-Cooling
4-Fan

Will need 5th wire for 2nd stage heating.
Should have 6th wire for Common, if you don't want to use battery on the t-stat all the time.
7th wire is suggested if you upgrade to 2 stage cooling.

But if you/they are not able to pull new wire, that's where the IAQ comes into the game.


That t-stat does have a humidity control, but has NO control of the blower's speed. it just "Overcools" the space up to 3˚. IAQ t-stat will slow down the blower if the home is over set point of % humidity, and the IAQ will then overcool the home if the humidity is 5% over set point.



Variable speed got a few things that you can gain.
- Fan "ON" mode, the blower is very quiet, and soft air flow for winter time comfort, also if up have media air filter system. the air is being filtered all times.

- Blower will be easy matched with your cooling Tonnage of system, and moves the right amount of air.

- Blower can be slowed down when it's tied to a humidistat to help dry out the home in the summer.

- Quiet ramping up to speed, and slow down to speed or off.

- Uses less power.




Comfort! Longer run times lead to comfort in the home.


You will only get single stage heating, and use timer for 2nd stage.


Kinda, just loose the slower blower for humidity control


Quiet, comfort and lower power bill.


Yes, up to 15 min max.

I have an older outside AC unit (Trane XE 1000 2.5 ton), so I assume it is only a 1-stager. Does the TCONT802 get me anything extra in cooling mode, or is the Comfort R settings on the board controlling the blower speeds, ramp-ups, etc..?? Can I "over-ride" or optimize the Comfort R settings thru the stat, in a way that the board can't do (more humidity control thru fan speed)??

Also, the question was asked IF the time for 2nd stage was cut-in adjustable, and you said "Yes, up to 15 minutes max". Are you saying that there is a board setting that will allow 2nd-stage to come on after 15 minutes instead of 10 minutes, in Heating Mode??

thanks again.

[cmajerus]

I have an older outside AC unit (Trane XE 1000 2.5 ton), so I assume it is only a 1-stager. Does the TCONT802 get me anything extra in cooling mode, or is the Comfort R settings on the board controlling the blower speeds, ramp-ups, etc..?? Can I "over-ride" or optimize the Comfort R settings thru the stat, in a way that the board can't do (more humidity control thru fan speed)??

Also, the question was asked IF the time for 2nd stage was cut-in adjustable, and you said "Yes, up to 15 minutes max". Are you saying that there is a board setting that will allow 2nd-stage to come on after 15 minutes instead of 10 minutes, in Heating Mode??

thanks again.

depends how old the unit is they switched boards a couple yrs ago to include a diswitch setting that does 30sec,5min.10min,15min. I think these are the positions.

[jefferyb]

depends how old the unit is they switched boards a couple yrs ago to include a diswitch setting that does 30sec,5min.10min,15min. I think these are the positions.

The furnace (xv80) was just installed two weeks ago..

[cmajerus]

then it can be set that way, but is best to use a 2 stage tstat and switch to 2nd stage by temp need instead.

[mayguy]

I agree with C, Get yourself a two stage. You'll be glad you got it for the best comfort you get.

When my parents had their house built 3 years ago, the electrction only put in the single t-stage t-stat, I changed it out to a VP two stage, and the family room in the basement was not as cold as it was before when the furnace was running on the timer.