LET d = 0
LET rmt_relay1 = 0
LET t3 = 100 ' 10 sec
DO
  ' Control heater
  IF relay3 = 0 THEN
    ' We are in remote control mode
    ' Sets thresholds for house temp
    IF relay2 = 0 THEN
      LET b = 5.0
      LET c = 5.5
    ELSE
      LET b = 17.2
      LET c = 17.7
    END IF
    IF relay1 = 0 THEN
      'Heater is off
      LET a = 0
      IF temp1 < b THEN
        LET a = 1
      END IF
      IF temp2 > 60 THEN
        LET a = 1
      END IF
      IF temp4 < 2.8 THEN
        LET a = 1
      END IF
      IF t0 > 0 THEN
        LET a = 0
      END IF
      ' Switch on
      IF a = 1 THEN
        LET t1 = 1200 ' Min on = 2 min
	LET t2 = 12000 ' Max on = 20 min
	LET relay1 = 1
      END IF
    ELSE
      'Heater is on
      LET a = 0
      IF temp1 < c THEN
        LET a = 1
      END IF
      IF temp2 > 55 THEN
        LET a = 1
      END IF
      IF temp4 < 3.5 THEN
        LET a = 1
      END IF
      IF t1 > 0 THEN
        LET a = 1
      END IF
      IF t2 = 0 THEN
        LET a = 0
      END IF
      ' Switch off
      IF a = 0 THEN
        LET t0 = 2400 ' Min off = 4 min
	LET relay1 = 0
      END IF
    END IF
  ELSE
    LET t0 = 0
    LET t1 = 0
    LET t2 = 0
    LET relay1 = 0
  END IF

  ' Control pipes
  IF t3 = 0 THEN
    IF temp3 < 4 THEN
      LET rmt_relay1 = 1
      LET d = 1
      LET t3 = 3000 ' 5 min
      LOG
    ELSE
      IF d = 1 THEN
	LET rmt_relay1 = 0
	LET d = 0
	LET t3 = 600 ' 1 min
	LOG
      END IF
    END IF
  END IF

LOOP
END