Range-Extending Booster

Start Here/User Guide

Step 1: Charge your Booster: 20 min.

  • Use the included USB cable and any USB power supply (a phone charger works great)
  • The light will blink amber as the Booster charges
  • When the Booster is charged, the light will turn green
  • Don't insert a thermometer into the Booster yet (see below)

Step 2: Update the firmware

  • Open the Combustion Inc. app on a Bluetooth-enabled device (i.e. your phone)
  • Unplug the Booster from the USB
  • Don't insert a thermometer into the Booster yet! (The Booster turns its radio off when a thermometer is inserted.)
  • Press the button (light) to turn on the radio.
  • The Booster should be blinking white x3 - that means "searching" (repeats every few seconds)
  • Place the Booster and mobile device close together
  • Tap the Combustion logo on the app
  • Follow the onscreen instructions

(Note: updating the firmware will change the basic feedback - blink patterns - on the Booster. The instructions on this page are based on the updated firmware. Full list of blink patterns at the bottom of this page.)

Step 3: Link your Booster to your Predictive Thermometer

  • Unplug the Booster from the USB
  • The light will flash white 3 times in a row to show it’s searching (this sequence repeats)
  • Hold a (fully charged) Predictive Thermometer near the Booster 
  • A single white blink indicates the link has been established (it will blink every 5 seconds)

Congrats, your Booster is now repeating the Thermometer’s Bluetooth signal!

Repeater mode

When the Booster is not plugged in to USB power, it will search for linked Combustion tools (Predictive Thermometer, Display) to connect with. You'll see a repeating pattern of 3 white blinks.

If connected the Booster will remain on. You'll see a repeating pattern of 1 white blink (every 5 seconds).

If no connection is found, the Booster will stop searching after 2 minutes and enter low-power mode. 

Power and Charging

Portable Charger Mode

With the Booster unplugged, the onboard battery can recharge your Predictive Thermometer. The Booster does not need to be "powered on" to do so.

The light will blink amber for a short time when the thermometer is inserted and begins to charge.

To check charge status, press the button (light).

If the light turns amber, it's still charging.

If the light turns green, the thermometer is charged.

The Booster can keep a thermometer topped-up and ready-to-go for up to 6 months in storage (!).

NOTE: Booster will not act as a repeater while it’s recharging a thermometer.

Wall Charger Mode

With the Booster plugged in, it will recharge itself and the Predictive Thermometer.

If either is charging, the light will blink amber.

When both are charged, the light will turn green.

With the Predictive Thermometer in the Booster, repeater mode is deactivated.

Booster Power Settings

Use the included USB cable and any USB power supply (a phone charger works great)

  • The light will blink amber as the Booster charges
  • When the Booster is charged, the light will turn green

When not connected to USB:

  • To turn off: hold the button (light) for 1 second.
  • To turn on: press the button (light)

NOTE: if no Bluetooth connection is found, the Booster will power itself down after 2 minutes. 


The Booster works with other MeatNet™-enabled tools to seamlessly extend the range of your Predictive Thermometer(s).

Each tool (e.g. Booster or Display) automatically repeats signals from other linked Combustion tools.

In practice, what you'll most likely do is place a Booster nearest the Predictive Thermometer you want to boost to get a strong first hop.

Use that to relay the signal to (and from) the Display or App where you are monitoring + controlling your cook.

Or use the Display as the second "node" to re-boost the signal to the app.

Each of these nodes creates a new broadcast location with a signal strength of about 330ft (100m) if unobstructed.

It's theoretically possible to "daisy-chain" multiple nodes together to get really absurd range.

For now, we recommend limiting the number of repeater nodes to 3 or less (e.g. 2 Boosters + 1 Display).

MeatNet™ is an ad-hoc mesh network. That means it’s a network that forms itself and doesn’t require any intervention - you don’t have to have an access point… or router.

Every part of Combustion's MeatNet cooperates but they do not depend on each other to work.

Combustion devices (and the app) communicate directly with one another (peer-to-peer). 

NOTE: MeatNet is enabled after you apply the initial firmware update.

Linking for Multinode MeatNet

To share signals correctly, all of the Combustion Tools involved must be linked.

(And yes, you can do this with multiple Boosters, with or without a Display.)

Start by updating the firmware on all devices* (if you haven't yet).

Then do this:

  1. Put probes in Boosters (this turns Booster radio off) and turn off Display (hold start/stop)
  2. Put all devices within a couple inches of each other
  3. Remove probes from Boosters and turn on Display, and set probes in the pile of devices
  4. Let all devices sit for 1-2 minutes

That's it! They're all linked together and will relay signals from all linked thermometers.

They will also relay settings from the App or linked Display back to the chosen thermometer.

Typically the first connection (e.g.Thermometer to Booster) has the shortest effective range because grills and smokers are very strong radio obstructions. More about that on the FAQ.

TIp: you can see how many "hops" your signal is using by digging into "debug mode" in the app.


The Booster light – what it’s trying to tell you:

Amber = Charging

If the Booster is plugged in to USB, the blinking amber light indicates the onboard battery is charging and/or the Predictive Thermometer is charging.

In portable charger mode, press the button (light). An amber light response indicates the thermometer is still charging.

The indicator will turn off after 5 seconds.

Green = Charged!

When plugged in, that means the Booster is charged and the Predictive Thermometer (if it's in there) is also fully charged.

In portable charger mode, press the button (light). A green light response indicates the thermometer is fully charged.

The indicator will turn off after 5 seconds.

Blinking White x3 = Searching

A repeated pattern of 3 white blinks indicates that the Booster is searching for linked tools within range.

It will only connect to Combustion tools that have been linked already.

Follow the linking steps above.

Single White Blink = Connected/Repeating

When the Booster is connected to a Predictive Thermometer (either directly or via another Booster/Display), it will repeat and rebroadcast the signal.

A single white blink indicates this connection is live! The blink will repeat every 5 seconds.

Quick Red Blink = Low Battery

When the onboard battery is low, the Booster will repeat a very quick red blink. Time to recharge it!

Overlapping Patterns?

It's possible that more than one light pattern will be triggered at a time.

For instance, a Booster which is recharging itself (blinking amber) may also be repeating (single white blink).

If you see a confusing light pattern, it's most likely two simple patterns that are overlapping.

Booster troubleshooting

The app is not seeing the Booster?

Is the thermometer charged and on?

If the thermometer is in a charger or Booster, it will enter "standby" and stop transmitting data.

Is the thermometer inserted into the Booster?

The Booster turns its radio off when a thermometer is inserted. It becomes wholly devoted to keeping the thermometer charged. To turn its
radio on, remove the thermometer.

Is the Booster on?

The Booster turns on automatically when a thermometer is removed. If the thermometer was not in it, it may have entered "standby." Press the button (light). If the light is on or blinking, the Booster is on.

Is the Booster linked to the thermometer?

A linked Booster will blink once (white) every 5 seconds. That means it's repeating. If not, scroll up this page and follow the instructions under "step 3."

If that doesn't help:

In the app go to settings (3 dots) --> debug mode. You will see a "hop count."

If the app is not detecting a repeater (Booster or Display), that number will read "0."

Otherwise, it should show the number of repeaters involved (e.g. "1").

Can't tell if it's recharging the thermometer?

When recharging in "portable charger mode," you won't see a light unless you press the button.

Rest easy, if the Booster battery is charged, it will be recharging your thermometer as needed.

To check the charge status of the thermometer, press the button (light) on the Booster.

If the thermometer is charging, the light will glow amber. If it's fully charged, it will glow green.

The status light will stop glowing after 5 seconds to save battery.

Difficulty updating the firmware?

If you try to update the firmware with a thermometer inserted, it won't happen. Inserting the thermometer turns the radio off - the Booster becomes wholly dedicated to charging.

When you unplug the Booster from the USB, press the button (light) to turn it on! Otherwise the radio will remain off - it won't blink and won't connect to anything, including the app.

Be sure you have the latest version of the app before updating firmware. If you're not sure, check the App Store or Google Play (links in footer below).

Blinking amber after full charge?


There is a known software bug with the Booster where if you take a fully charged Booster (green light) off of USB power and plug it in again, it will blink amber as if it's recharging.

As one user described it:

“Plugged in for 24hrs goes green, unplug no light, and plugged back in goes back to orange blinking”

Don't worry!

It doesn't mean the Booster is discharged or needs recharging.

That blinking will stop after 1-2 minutes.

There's something about this input that makes the charging chip very grumpy. It thinks it needs to recharge, even though the battery is fully charged.

It's safe to ignore this bug.

We'll be addressing this hopefully in the next firmware package.

NOTE: When you unplug the Booster, it still needs to be turned on!

Press the button to turn it on and it will start blinking either 3 white blinks (searching) or 1 white blink (connected).

(Also, removing the thermometer from the Booster will turn it on. That's normally how you do it.)

To switch off the Booster's radio (saves power), hold the button (light) for 1 second.