Temperature controlled relay

Development Boards Arduino
11

I have added the line you suggested and now get A2 to display either a 1 or 0 depending on weather there is the defined difference between my two temperature sensors. It works like a charm. Now I am trying to have it turn on relay 1 on digital input 2. I think I am confusing analog inputs with digital inputs. I am only using the serial monitor so I can see what is going on when testing. How do I get D2 to go HIGH (turning on relay 1) when A2 reads 1? (or am I just complicating things?)

// We'll use analog input 0 and 1 to measure the temperature sensor's
// signal pins.
 
const int temperatureSPin = 0;
const int temperatureTPin = 1;

 int relayPin = A2;      // select the pin for the relay

void setup()
{
  // declare the relayPin as an OUTPUT:
 pinMode(relayPin, OUTPUT); 
  
  Serial.begin(9600);
}

void loop()

{
   
  float voltageS,voltageT, degreesCS, degreesCT, degreesF;

  voltageS = getVoltage(temperatureSPin);
   voltageT = getVoltage(temperatureTPin);
   //print voltages at this point. if done after the conversion
   //you only get a value of 1 for some reason
 Serial.print("   vTank: ");
  Serial.print(voltageT);
  Serial.print("vSolar: ");
  Serial.print(voltageS);
  
   degreesCS = (voltageS - 0.5) * 100.0;
   degreesCT = (voltageT - 0.5) * 100.0;
  
  degreesF = degreesCS * (9.0/5.0) + 32.0;

{   
  
if ((degreesCS-degreesCT)>1) digitalWrite (relayPin,HIGH);
else digitalWrite (relayPin,LOW);

}
  
  Serial.print("  deg CS: ");
  Serial.print(degreesCS);
  //Serial.print("  deg F: ");
  //Serial.println(degreesF);
  
 
  Serial.print("  deg CT: ");
  Serial.print(degreesCT);
  Serial.print("  relayPin: ");
  Serial.println(digitalRead(relayPin));
 
  delay(1000); //off time
}

float getVoltage(int pin)
{
    return (analogRead(pin) * 0.004882814);
}
 
/*void loop()/*my second if else statement that gives more errors grrrrr

{
   if (relayPin,HIGH)digitalWrite (A2,HIGH); 
else digitalWrite (A2,LOW);

}*/