Honeywell Home, Resideo and the thermostat on your wall
Honeywell spun off Resideo Technologies as a separate company in October 2018, and Resideo has made Honeywell Home products since then under a long-term license to the name. The 2026 Honeywell Home website still carries the notice that the trademark is used under license from Honeywell International. The newest smart thermostats, the X8S and X2S, even run on Resideo's First Alert app.
For your house, the practical point is that older Honeywell thermostats, humidifiers and air cleaners are still supported, and their model numbers are still on Honeywell Home's support pages. We work on all of it, and we install current Honeywell Home thermostats where they fit the house and the equipment. Our thermostat service page covers the rest of our thermostat and zoning work.
Installing one: C-wires and wiring
Start with the wires. Both X-Series thermostats require a C-wire, the common wire that gives a thermostat steady 24-volt power. Many Twin Cities houses wired before smart thermostats have a four-wire cable with no C, and older boiler homes may have only two wires. When a spare conductor is folded back in the wall, we connect it at both ends. When there isn't one, we run a new cable or use Honeywell's C-wire adapter. Our C-wire guide explains the options.
The T6 Pro is the other common install. It runs hardwired or on two AA batteries, which makes it a practical choice on older wiring when you don't need Wi-Fi. It mounts on Honeywell's UWP wall plate, and Honeywell sells it through contractors rather than stores.
Which Honeywell Home thermostat fits a heat pump?
Stage count matters on the equipment Minnesota homes are adding now. Honeywell lists the X8S for heat pumps with up to four heat and two cool stages, and the X2S for up to two heat and one cool. The T6 Pro comes in versions: the TH6320U handles up to three heat and two cool stages on a heat pump, while the TH6220U is a two-heat, two-cool model for a conventional furnace and AC.
Match those numbers to the equipment before anything else. A cold-climate heat pump with electric strips, or one paired with a gas furnace, needs its backup heat and outdoor changeover set for a Minnesota winter, or the strips run on mild mornings and the electric bill climbs. Our post on dual fuel heating explains the handoff, and our Honeywell Home vs Sensi comparison lines up staging and C-wire needs if you're still choosing a model.
Could a Honeywell thermostat be why there's no heat?
Plenty of no-heat calls in October and no-cool calls in June start at the thermostat, not the furnace or condenser. On a Honeywell, we check these first:
- A blank screen. Dead AA batteries on a battery model, or no 24-volt power on a hardwired one. A tripped furnace switch or a blown fuse on the furnace control board does the same thing.
- A fuse blown during a DIY swap. Two bare wires touching at the wall short the transformer circuit, and the furnace ignores every call until the fuse is replaced.
- Installer settings. System type, stage count and the O/B reversing valve setting have to match the equipment. Set wrong, a heat pump cools when you ask for heat.
- A delay that looks like a failure. Most thermostats hold the compressor off for a few minutes after it stops, so an AC or heat pump won't restart right away.
If the thermostat checks out, we move to the furnace or condenser on the same visit.
Honeywell humidifiers and air cleaners
Honeywell's HE280 bypass humidifier runs water over a pad in its PerfectFLO tray, and the pad should be replaced every heating season. The HM750 makes steam with electrodes, and its cylinder slowly fills with minerals, faster on hard well water. With either one, set the humidity lower as it gets colder outside, roughly 25–35% in cold weather and lower in deep cold, or the windows frost. See our humidifier service for installs.
The F100 and F200 media air cleaners hold a 4-inch filter in the return duct. Before putting an F200 with its MERV 13 filter on an older furnace, we check that the return duct and blower can handle it.
A service call is a $79 trip charge, waived when you approve the repair, with a written price before any work starts. Installed air quality equipment runs $350–$2,800. Call 612-429-3465, 7am–9pm, seven days a week.
Honeywell Home questions
Is Honeywell Home still made by Honeywell?
Not directly. Honeywell spun off Resideo Technologies as a separate company in October 2018, and Resideo makes Honeywell Home thermostats, humidifiers and air cleaners under an exclusive trademark license that runs up to 40 years. The Honeywell Home website still carries that license notice in 2026. On your wall nothing changes: support for older Honeywell models comes through Resideo.
Why does my new Honeywell Home X2S or X8S need a C-wire?
Honeywell lists a C-wire as required on both, because they keep Wi-Fi running all the time and need steady 24-volt power. Plenty of older Minnesota houses have a four-wire cable with no C. We connect a spare conductor at both ends when one is in the wall, run a new cable, or use Honeywell's C-wire adapter, which it sells as an X8S accessory. A two-wire boiler circuit usually needs new cable.
My heat pump blows cold air in heat mode after a new Honeywell thermostat. Why?
Usually the reversing valve setting. Depending on the heat pump brand, the O/B wire switches the valve for cooling or for heating, and the thermostat's installer setup has to match. Set wrong, the unit cools when you ask for heat and heats when you ask for cooling. Backup heat and outdoor lockout settings come next, then the wiring itself. We check all three before replacing anything.
How often should the pad in a Honeywell humidifier be changed?
Once a heating season on the HE bypass models, and sooner on hard well water. The HE280 takes an HC26P pad and the older HE240 an HC22P, and a scaled pad puts out far less moisture. The HM750 steam unit uses a replaceable cylinder instead, which fills with minerals over time. We change pads and check the solenoid valve and drain line during a fall tune-up.
Can a Honeywell Home thermostat run my whole-home humidifier?
Some can. Honeywell lists humidity and ventilation control on the X8S, with added equipment required, and doesn't list it on the X2S. Many Honeywell humidifiers come with their own control instead: the HE280D2001 includes an electronic humidistat, and the HM750 ships with a HumidiPRO H6062 control. Whichever one runs it, the target should drop as it gets colder outside, or the windows frost.
Sources
- Honeywell Home official site honeywellhome.com