Why isn't brewpi bringing the heater on?

Title says it all, it’s been sitting under temp for an hour and a half and the heater won’t come on. I power cycled the device a couple times, and the heater came on for a few seconds but then went back to idle…

{
  "kind": "Control",
  "pids": [
    {
      "kind": "Pid",
      "name": "heater1",
      "enabled": true,
      "setPoint": {
        "kind": "SetPointSimple",
        "name": "fridgeset",
        "value": 10
      },
      "inputSensor": {
        "kind": "TempSensorFallback",
        "onBackupSensor": false,
        "sensor": {
          "kind": "TempSensor",
          "name": "fridge",
          "sensor": {
            "kind": "OneWireTempSensor",
            "value": 18.5625,
            "connected": true,
            "address": "280B5CC10700009E",
            "calibrationOffset": 0
          }
        }
      },
      "inputError": 8.5664,
      "Kp": 10,
      "Ti": 600,
      "Td": 100,
      "p": -85.6641,
      "i": 0,
      "d": 2.5391,
      "actuatorIsNegative": false,
      "outputActuator": {
        "kind": "ActuatorPwm",
        "value": 0,
        "period": 4,
        "minVal": 0,
        "maxVal": 100,
        "target": {
          "kind": "ActuatorMutexDriver",
          "mutexGroup": {
            "kind": "ActuatorMutexGroup",
            "deadTime": 1800000,
            "waitTime": 0
          },
          "target": {
            "kind": "ActuatorPin",
            "state": false,
            "pin": 16,
            "invert": false
          }
        }
      }
    },
    {
      "kind": "Pid",
      "name": "heater2",
      "enabled": true,
      "setPoint": {
        "kind": "SetPointSimple",
        "name": "beer2set",
        "value": null
      },
      "inputSensor": {
        "kind": "TempSensor",
        "name": "beer2",
        "sensor": {
          "kind": "TempSensorDisconnected",
          "value": null,
          "connected": false
        }
      },
      "inputError": null,
      "Kp": 0,
      "Ti": 0,
      "Td": 0,
      "p": 0,
      "i": 0,
      "d": 0,
      "actuatorIsNegative": false,
      "outputActuator": {
        "kind": "ActuatorPwm",
        "value": 0,
        "period": 0,
        "minVal": 0,
        "maxVal": 100,
        "target": {
          "kind": "ActuatorMutexDriver",
          "mutexGroup": {
            "kind": "ActuatorMutexGroup",
            "deadTime": 1800000,
            "waitTime": 0
          },
          "target": {
            "kind": "ActuatorNop",
            "state": false
          }
        }
      }
    },
    {
      "kind": "Pid",
      "name": "cooler",
      "enabled": true,
      "setPoint": {
        "kind": "SetPointSimple",
        "name": "fridgeset",
        "value": 10
      },
      "inputSensor": {
        "kind": "TempSensorFallback",
        "onBackupSensor": false,
        "sensor": {
          "kind": "TempSensor",
          "name": "fridge",
          "sensor": {
            "kind": "OneWireTempSensor",
            "value": 18.5625,
            "connected": true,
            "address": "280B5CC10700009E",
            "calibrationOffset": 0
          }
        }
      },
      "inputError": 74.9961,
      "Kp": 20,
      "Ti": 7200,
      "Td": 20,
      "p": -1499.9219,
      "i": 0,
      "d": 0.0781,
      "actuatorIsNegative": true,
      "outputActuator": {
        "kind": "ActuatorPwm",
        "value": 100,
        "period": 2400,
        "minVal": 0,
        "maxVal": 100,
        "target": {
          "kind": "ActuatorMutexDriver",
          "mutexGroup": {
            "kind": "ActuatorMutexGroup",
            "deadTime": 1800000,
            "waitTime": 0
          },
          "target": {
            "kind": "ActuatorTimeLimited",
            "minOnTime": 180,
            "minOffTime": 900,
            "maxOnTime": 65535,
            "state": false,
            "target": {
              "kind": "ActuatorPin",
              "state": false,
              "pin": 17,
              "invert": false
            }
          }
        }
      }
    },
    {
      "kind": "Pid",
      "name": "beer2fridge",
      "enabled": true,
      "setPoint": {
        "kind": "SetPointSimple",
        "name": "beer1set",
        "value": 20
      },
      "inputSensor": {
        "kind": "TempSensor",
        "name": "beer1",
        "sensor": {
          "kind": "OneWireTempSensor",
          "value": 18.9375,
          "connected": true,
          "address": "288269C00700003B",
          "calibrationOffset": 0
        }
      },
      "inputError": 5.5664,
      "Kp": 10,
      "Ti": 14400,
      "Td": 0,
      "p": -55.6641,
      "i": 0,
      "d": 0,
      "actuatorIsNegative": false,
      "outputActuator": {
        "kind": "ActuatorSetPoint",
        "targetSetPoint": {
          "kind": "SetPointSimple",
          "name": "fridgeset",
          "value": 10
        },
        "targetSensor": {
          "kind": "TempSensor",
          "name": "fridge",
          "sensor": {
            "kind": "OneWireTempSensor",
            "value": 18.5625,
            "connected": true,
            "address": "280B5CC10700009E",
            "calibrationOffset": 0
          }
        },
        "referenceSetPoint": {
          "kind": "SetPointSimple",
          "name": "beer1set",
          "value": 20
        },
        "output": -10,
        "achieved": -1.4375,
        "minimum": -10,
        "maximum": 10
      }
    }
  ]
}

After the power cycle, I dropped the actuator deadtime down to 1s and the heater came on. I reset dead time back to 1800, and everything appears to be working fine. Not sure why it got hung up but I think we’re all good now.