---
tag: m0191
title: Wait for Chamber Temperature
brief: Wait for the chamber to reach target temperature
author: shitcreek
contrib: thinkyhead

group: thermal

codes: [ M191 ]
related: [ M141 ]

notes:
- This command (as well as [`M109`](/docs/gcode/M109.html) and [`M190`](/docs/gcode/M190.html)) can block new commands from the host. To break out of wait for temperature using [`M108`](/docs/gcode/M108.html) from the host, enable `EMERGENCY_PARSER`.
- Use [`M141`](/docs/gcode/M141.html) to set the chamber temperature and proceed without waiting.

parameters:

- tag: S
  optional: true
  description: Target temperature (wait only when heating).
  values:
  - tag: temp
    type: float

- tag: R
  optional: true
  description: Target temperature (wait for cooling or heating).
  values:
  - tag: temp
    type: float

examples:
- pre: Set target chamber temperature and wait (if heating)
  code: M191 S80
- pre: Set target chamber temperature, wait even if cooling
  code: M191 R40

---

This command optionally sets a new target chamber temperature and waits for the target temperature to be reached before proceeding. If the temperature is set with `S` then it waits *only when heating*.
