MQTT Number is not updating

I have an ESP3266 that controls the pump of my floor heating. It checks the temperature of the input and returning water. If the input is higher than the return temperature the punp is switch on. This works fine but now I made the setpoint variable and can be set through MQTT.
The ESP3266 is fully working.

I want to set the setpoint from the lovelace and therefor I added a MQTT number.
The current set value is correctly displayed on the lovelace, but when I change the number it is not send to the ESP. Online I can not find much info over the MQTT number.
Who knowns what I have done wrong?

number:
  - platform: mqtt
    name: "underfloor_heating_pump_setpoint_temp"
    unique_id: "underfloor_heating_pump_setpoint_temp"
    state_topic: "esp8266/pump"
    value_template: "{{ value_json.setpoint }}"
    command_topic: "esp8266/pomp/setpoint"
    command_template: "{{ value }}"
    unit_of_measurement: "°C"
    min: 10
    max: 45
    step: 1

I don’t think you need command_template unless you want to set the number from somewhere else.

Without that line a update is also not pushed.
when I send it using the MQTT publish a packet test then it is changed but not using the slider in lovelace.

Is this a typo?

Use something like mosquitto_sub (or click on configure in the MQTT integration) and subscribe to something like esp8266/# to see what’s going on.

Yes it was a typo, should be pump! Thanks for finding it!