New Construction Install S9x2 paired with XL18i

so I am stuck in between a rock and a hard spot and hopefully I am not beyond the rules with in this website. Ihired a contractor to install the above, first go around they install a 60k btu furnace when it was supposed to be a 80k btu. Now that this is corrected, I feel like I have a under educated contractor. They would not set up my ecobee stat as they were not familiar with it etc. everything is all installed and operating but I have yet to see 2 stage of heat pump, have yet to see stage 1 and stage 2 of Aux heat and have yet to see stage 1 or stage 2 of cooling. I paid these guys a lot of money and I feel like something is not right. I have a couple questions:

1. It appears that the heat pump only runs in 1 stage and I know it is a 2 stage compressor, so is this a wiring function at the unit or a set up function at the ecobee

2. what should the compressor minimum outdoor temperature be set at with in the ecobee ( what is the safer operational range for the compressor)

You should have had them put in the 824 thermostat and you would have better control of the system as it is designed for that system.

You said they put in a 60k instead of an 80k furnace who did the load calc to determine equipment size, duct size, etc?

As far as the minimum temp to run the heat pump at that comes down to heat pump out put and house load as the temp falls. The other side of that coin is do you want it set for efficiency or comfort.

The heat pump will put out heat below the temp where it will no longer keep up with the heat loss of the house. If the heat pump is more efficient than the gas furnace at say 25° for example but it will not keep the house warm so the furnace will have to run at times to keep the house to temp. If the heat pump runs cheaper than the furnace that may make sense to keep it running and let the furnace cycle to keep the house to temp. If it costs more it may make sense to shut the heat pump off at 30 or 40 depending on where it meets the needs of the house.

All this should have been figured out by the person that did the load calc (Man J).

yea the guys I paid failed me. Long and short the house is a engineered SIP wall Home, really efficient etc. This is in a rural area in northern Michigan so propane is expensive, but electricity is also expensive compared to a populated area. Is the 2 stage a function of jumpers at the heat pump or is it a function of wiring from pump to furnace to stat

To answer your question, it’s both wiring and setup at all 3. The XL18i is a 2 stage unit, the S9X2 is capable of 2 stage compressor operation and is a 2 stage furnace and the Ecobee is capable of controlling both. However I will agree with BNME8EZ, the Trane XL824 would’ve been the best option to control your system.

Did you provide the Ecobee thermostat or did the installing contractor?

Originally Posted by taylor2

To answer your question, it’s both wiring and setup at all 3. The XL18i is a 2 stage unit, the S9X2 is capable of 2 stage compressor operation and is a 2 stage furnace and the Ecobee is capable of controlling both. However I will agree with BNME8EZ, the Trane XL824 would’ve been the best option to control your system.

Did you provide the Ecobee thermostat or did the installing contractor?

The contractor told me to pick out a stat. Looking at the xl824 options I am not really seeing any setting that jump out at me that are not offered in the ecobee. What I dont get is this company is a trane company so I assume all trane people are not “Trane comfort Specialist”

Correct, not all Trane dealers are Trane Comfort Specialists. Part of the benefit of the XL824 is the decades of algorithms built into that controller that in my experience, especially with dual fuel and multistage equipment, provides the best performance and efficiency/ comfort depending on setup. All that aside, the Ecobee is perfectly capable control your system if wired and programmed properly.