# Honeywell Home Prestige IAQ Thermostat with RedLINK

*Honeywell Home / THX9421R5021WW/U, YTHX9421R5085WW/U, YTHX9421R5101WW/U, YTHX9421R5127WW/U, YTHX9421R7001WW/U*

> The Honeywell Home Prestige IAQ Thermostat with RedLINK is a two-wire color touchscreen thermostat that reaches the internet through a RedLINK Internet Gateway and works with Alexa and Google Assistant. It suits Google Home and Alexa users through an integration (the maker's hub).

- Canonical page: https://smarthomecanon.com/devices/honeywell-home-prestige-iaq-thermostat-with-redlink
- Last checked: 2026-10-16

## Key facts

| Fact | Value |
| --- | --- |
| Brand | [Honeywell Home](https://smarthomecanon.com/brands/honeywell-home) |
| Category | Thermostat |
| Model numbers | THX9421R5021WW/U, YTHX9421R5085WW/U, YTHX9421R5101WW/U, YTHX9421R5127WW/U, YTHX9421R7001WW/U |
| Status | Current[^1] |
| Connection | RedLINK[^1] |
| Needs | RedLINK Internet Gateway (THM6000R7001/U) for remote access[^1] |
| Stages | Up to 4 heat/2 cool heat pump, up to 3 heat/2 cool conventional[^1] |
| Power | Battery operated[^1] |
| Alexa | Yes[^1] |
| Z-Wave | unknown |

## Integration paths

**How the Honeywell Home Prestige IAQ Thermostat with RedLINK connects**

| Path | Requires | Local | Features lost |
| --- | --- | --- | --- |
| [Proprietary + hub](https://smarthomecanon.com/protocols/proprietary-gateway) | RedLINK Internet Gateway (THM6000R7001/U) for remote access[^1] | unknown | unknown |

**Platform support for the Honeywell Home Prestige IAQ Thermostat with RedLINK**

| Path | Platform | Support | Integration |
| --- | --- | --- | --- |
| Proprietary + hub | [Amazon Alexa](https://smarthomecanon.com/platforms/alexa) | Via integration[^1] |  |
| Proprietary + hub | [Google Home](https://smarthomecanon.com/platforms/google-home) | Via integration[^1] |  |

## Related pages

- [Honeywell Home RedLINK, Z-Wave and ductless thermostats](https://smarthomecanon.com/lines/honeywell-home-redlink-z-wave-and-ductless-thermostats) (line)
- [Honeywell Home](https://smarthomecanon.com/brands/honeywell-home) (brand)
- [Proprietary radio with a hub](https://smarthomecanon.com/protocols/proprietary-gateway) (protocol)
- [Amazon Alexa](https://smarthomecanon.com/platforms/alexa) (platform)
- [Google Home](https://smarthomecanon.com/platforms/google-home) (platform)

## Sources

[^1]: Honeywell Home: Prestige IAQ Thermostat with RedLINK product page. https://www.honeywellhome.com/products/prestige%C2%AE-iaq-thermostat-with-redlink%C2%AE (manufacturer, checked 2026-10-16)