King Thermostat
Your phone becomes the thermostat: leave it on a table in the room overnight, and the app starts and stops the heater to hold the temperature you pick.
How it worksPro: everything else Pro
US$10 a year, with a 7-day free trial once per phone. Start your free week.
Prefer USDC? Pay a year with USDC.
Free stays free: Always Connected, Start and Stop, live status, fault names and CO Guard are for everyone.
Pro controls
Set the Power Level or the heater's own thermostat from the app.
How it worksTimers
Run for a while, then stop. Or start at a set time.
How it worksHeat Schedules
Heat at set times every week, overnight too.
How it worksRoom temperature
The room's temperature from the Phone sensor or a Bluetooth thermometer (Beta), not just the heater's.
How it worksHeat Graph
The room, the heater and the battery over time.
How it worksHistory and Change Ledger
Everything that happened to your heater, and who or what did it.
How it worksService Hours
Heating hours, starts and hours since the last service, counted on this phone.
How it worksSettings Guard
Find out when someone else changes your heater, or have the app put your settings back.
How it worksStay-Off
Keeps this heater off. If anything turns it on (a remote, an RF thermostat, someone at the panel), the app stops it again.
How it worksBattery Saver
Warns when the battery runs low, and stops the heater before it's flat.
How it worksSmart Start
Runs on a low Power Level start and finish at full power.
How it worksCleaning Cycle
After long runs on low, full power for the last 15 minutes, as many owners do.
How it worksHeater health alerts
A warning when a fault shows, the flame looks weak, or a start didn't finish.
How it worksFault help
What each fault means and what to check, step by step.
How it worksWall Display
Turn a spare phone or tablet into a wall thermostat.
How it worksMore than one heater
Keep every heater you own in one app.
How it worksFree and Pro
| Feature | Free | Pro |
|---|---|---|
| Always Connected, in the background | Yes | Yes |
| Hold to start and Stop | Yes | Yes |
| Live status and the King Dial | Yes | Yes |
| Fault names with the heater's code | Yes | Yes |
| CO Guard (heaters with a CO sensor) | Yes | Yes |
| °C or °F, Hand Off, Demo Heater | Yes | Yes |
| Power Level and Heater Thermostat from the app | No | Yes |
| King Thermostat on the room temperature | No | Yes |
| Timers and Heat Schedules | No | Yes |
| Heat Graph, Service Hours, History | No | Yes |
| Settings Guard and Stay-Off | No | Yes |
| Battery Saver, Smart Start, Cleaning Cycle | No | Yes |
| Fault help and heater health alerts | No | Yes |
| Wall Display | No | Yes |
| More than one heater | No | Yes |
CO Guard is not a certified CO alarm. It only works for heaters with a CO sensor, while this phone is connected and nearby. Always keep a working CO alarm installed.
Give Pro
A year of Pro for someone else, as a link to send. Give Pro.
How do I buy it?
Start your free week on the phone that has the app. Pro switches on by itself.
What if Pro ends?
Its features switch off and nothing is sent to your heater. The free app keeps working.
Does Pro need an account?
No. There is no account, in the free app or in Pro.
Can I move Pro to a new phone?
Yes, twice in any 365 days: on the new phone, open More, tap Pro, then Enter a key, and paste your key. The old phone's Pro stops.
How do I cancel?
Through Link, which sells Pro: the link in any receipt, or app.link.com. Pro keeps working until the end of the year you paid for.
Can I pay with USDC?
Yes: USDC on Solana, US$10 for a year of Pro or for a gift, straight from your wallet app (pay with USDC). When your year is nearly up, add another from the Pro screen in the app.