heat-manage: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/heat-manage - from package: heat-common

You may install the required package with command apt-get install {package}

Error in other languages:
heat-manage: bevel nie gevind nie
heat-manage: comandă negăsită
heat-manage: comando não encontrado
heat-manage: commande introuvable
heat-manage: command not found
heat-manage: käsku ei ole
heat-manage: không tìm thấy lệnh
heat-manage: komanda nerasta
heat-manage: Kommando nicht gefunden.
heat-manage: kommandot finns inte
heat-manage: komut yok
heat-manage: nie znaleziono polecenia
heat-manage: níor aimsíodh an t-ordú
heat-manage: no se encontró la orden
heat-manage: no s'ha trobat l'ordre
heat-manage: opdracht niet gevonden
heat-manage: parancs nem található
heat-manage: perintah tidak ditemukan
heat-manage: príkaz nenájdený
heat-manage: příkaz nenalezen
heat-manage: команда не найдена
heat-manage: командата не е открита
heat-manage: 命令找不到
heat-manage: コマンドが見つかりません