Live supply and return temps on your phone, SMS alerts when the fire gets low or the system starts to freeze, and a full history going back as far as you want to scroll. Built by people who heat with wood — out in northwest Pennsylvania, where 7 feet of snow and below-zero stretches are part of every winter.
Outdoor wood boilers, indoor gasification units, biomass hydronic systems — if it has a supply and return line you can tap into, Tempist reads it. Central Boiler, Crown Royal, HeatMaster, Econoburn, WoodMaster, and plenty of older boilers nobody makes anymore.
The Mini goes in quiet and stays that way. The OG shows temps on the boiler itself for folks who like seeing numbers in the boiler shed too.
Dual DS18B20 temperature probes, long-range WiFi antenna so the signal reaches the house from the boiler shed. Headless, no display — everything lives on your phone.
The flagship monitor with an on-device OLED display. See live temps right at the boiler, plus everything the Mini does on your phone. Built for folks who like seeing the numbers in the shed.
A standard-range Mini is also available at $189.99 for installs where the boiler is close to the house.
Built from years of running our own boilers. No bloat, no "smart home integrations" you'll never use.
Supply temp, return temp, and ΔT updating every 30 seconds. Works on any phone, any browser — add to home screen and it acts like a native app.
Fire going out. Return line close to freezing. Overboil. Boiler offline for too long. You set the thresholds; you get the text.
Every reading, kept forever. Scroll back to last January's cold snap. Export to CSV for your own records any time.
We count your heat cycles, damper-open time, overboil events, and freeze events automatically. Useful for warranty and useful for you.
After a quick burn study on your specific setup, the system estimates how long until your fire needs reloading. Until then, a user-set feed timer and a temp-watcher have you covered.
When we ship improvements, they land on your device automatically. The boiler you bought today gets better every quarter.
Most installs go in without tools you don't already have. If you can tighten a 1/2 in. NPT fitting, you can install Tempist.
Screw the two DS18B20 probes into thermowells on your supply and return lines. We ship thermowell kits for standard pipe sizes; if your boiler already has thermowells, even easier.
No thermowells? Stainless thermowells from the shop start at $12.99; a full install kit with adapter is $34.99.
Power it up with the included 5V USB adapter. The device opens a local setup page — pick your WiFi, enter your password, done.
Using the long-range Mini? It'll reach your house from most boiler sheds. Weak signal? We have a high-gain antenna option.
Create an account at tempisthub.com, enter the serial number from the bottom of your device, pick your alert thresholds, and you're live.
Add the dashboard to your phone's home screen so it opens like an app.