diff --git a/src/ir_Trotec.cpp b/src/ir_Trotec.cpp
index 230ea22e2..8a0b3b2ab 100644
--- a/src/ir_Trotec.cpp
+++ b/src/ir_Trotec.cpp
@@ -347,7 +347,7 @@ bool IRrecv::decodeTrotec(decode_results *results, uint16_t offset,
 
 #if SEND_TROTEC_3550
 /// Send a Trotec 3550 message.
-/// Status: BETA / Probably works. Untested on real device.
+/// Status: STABLE / Known to be working.
 /// @param[in] data The message to be sent.
 /// @param[in] nbytes The number of bytes of message to be sent.
 /// @param[in] repeat The number of times the command is to be repeated.
@@ -491,21 +491,32 @@ uint8_t IRTrotec3550::getMode(void) const { return _.Mode; }
 /// Set the temperature.
 /// @param[in] degrees The temperature in degrees.
 /// @param[in] celsius Use celsius units. True, Celsius; False Fahrenheit.
-/// @note Fahrenheit is not yet supported. Waiting on data analysis.
 void IRTrotec3550::setTemp(const uint8_t degrees, const bool celsius) {
   setTempUnit(celsius);
   uint8_t minTemp = kTrotec3550MinTempC;
   uint8_t maxTemp = kTrotec3550MaxTempC;
+  if (!celsius) {  // Fahrenheit?
+    minTemp = kTrotec3550MinTempF;
+    maxTemp = kTrotec3550MaxTempF;
+  }
   uint8_t temp = std::max(degrees, minTemp);
   temp = std::min(temp, maxTemp);
-  _.Temp = _.Temp2 = temp - minTemp;
+  if (celsius) {
+    _.TempC = temp - minTemp;
+    _.TempF = celsiusToFahrenheit(temp) - kTrotec3550MinTempF;
+  } else {
+    _.TempF = temp - minTemp;
+    _.TempC = fahrenheitToCelsius(temp) - kTrotec3550MinTempC;
+  }
 }
 
 /// Get the current temperature setting.
 /// @return The current setting for temp. in degrees.
-/// @note Fahrenheit is not yet supported. Waiting on data analysis.
 uint8_t IRTrotec3550::getTemp(void) const {
-  return _.Temp + kTrotec3550MinTempC;
+  if (getTempUnit())  // Is Celsius?
+    return _.TempC + kTrotec3550MinTempC;
+  else
+    return _.TempF + kTrotec3550MinTempF;
 }
 
 /// Set the temperature unit that the A/C will use..
@@ -582,7 +593,7 @@ stdAc::state_t IRTrotec3550::toCommon(void) const {
   result.protocol = decode_type_t::TROTEC_3550;
   result.power = _.Power;
   result.mode = toCommonMode(_.Mode);
-  result.celsius = _.Celsius;
+  result.celsius = getTempUnit();
   result.degrees = getTemp();
   result.fanspeed = toCommonFanSpeed(_.Fan);
   result.swingv = _.SwingV ? stdAc::swingv_t::kAuto : stdAc::swingv_t::kOff;
diff --git a/src/ir_Trotec.h b/src/ir_Trotec.h
index 983f0a7fe..fd49ecef8 100644
--- a/src/ir_Trotec.h
+++ b/src/ir_Trotec.h
@@ -86,12 +86,11 @@ union Trotec3550Protocol{
     uint8_t Power    :1;
     uint8_t          :1;  // Unknown
     uint8_t TimerSet :1;
-    uint8_t Temp     :4;  // Temp +16 for degC)
+    uint8_t TempC    :4;  // Temp + kTrotec3550MinTempC for degC)
     // Byte 2
     uint8_t          :8;  // Unknown
     // Byte 3
-    uint8_t          :1;  // Unknown
-    uint8_t Temp2    :4;  // Temp +16 for degC)
+    uint8_t TempF    :5;  // Temp + kTrotec3550MinTempF for degF)
     uint8_t          :3;  // Unknown
     // Byte 4
     uint8_t          :8;  // Unknown
@@ -111,8 +110,9 @@ union Trotec3550Protocol{
 };
 
 const uint8_t kTrotec3550MinTempC = 16;
-const uint8_t kTrotec3550DefTempC = 25;
 const uint8_t kTrotec3550MaxTempC = 30;
+const uint8_t kTrotec3550MinTempF = 59;
+const uint8_t kTrotec3550MaxTempF = 86;
 
 // Legacy defines. (Deprecated)
 #define TROTEC_AUTO kTrotecAuto
diff --git a/test/ir_Trotec_test.cpp b/test/ir_Trotec_test.cpp
index 11b581281..fa06ca81b 100644
--- a/test/ir_Trotec_test.cpp
+++ b/test/ir_Trotec_test.cpp
@@ -280,8 +280,10 @@ TEST(TestTrotec3550Class, SetAndGetFan) {
 TEST(TestTrotec3550Class, SetAndGetTemp) {
   IRTrotec3550 ac(kGpioUnused);
 
+  // Celsius
   ac.setTemp(25);
   EXPECT_EQ(25, ac.getTemp());
+  EXPECT_TRUE(ac.getTempUnit());
   ac.setTemp(kTrotec3550MinTempC);
   EXPECT_EQ(kTrotec3550MinTempC, ac.getTemp());
   ac.setTemp(kTrotec3550MaxTempC);
@@ -290,6 +292,26 @@ TEST(TestTrotec3550Class, SetAndGetTemp) {
   EXPECT_EQ(kTrotec3550MinTempC, ac.getTemp());
   ac.setTemp(kTrotec3550MaxTempC + 1);
   EXPECT_EQ(kTrotec3550MaxTempC, ac.getTemp());
+  // Fahrenheit
+  ac.setTemp(72, false);
+  EXPECT_EQ(72, ac.getTemp());
+  EXPECT_FALSE(ac.getTempUnit());
+  ac.setTemp(kTrotec3550MinTempF, false);
+  EXPECT_EQ(kTrotec3550MinTempF, ac.getTemp());
+  ac.setTemp(kTrotec3550MaxTempF, false);
+  EXPECT_EQ(kTrotec3550MaxTempF, ac.getTemp());
+  ac.setTemp(kTrotec3550MinTempF - 1, false);
+  EXPECT_EQ(kTrotec3550MinTempF, ac.getTemp());
+  ac.setTemp(kTrotec3550MaxTempF + 1, false);
+  EXPECT_EQ(kTrotec3550MaxTempF, ac.getTemp());
+  // Celsius
+  ac.setTemp(25, true);
+  EXPECT_EQ(25, ac.getTemp());
+  EXPECT_TRUE(ac.getTempUnit());
+  uint8_t deg79F[9] = {0x55, 0xA3, 0x00, 0x14, 0x00, 0x00, 0x31, 0x40, 0x7D};
+  ac.setRaw(deg79F);
+  EXPECT_FALSE(ac.getTempUnit());  // Fahrenheit
+  EXPECT_EQ(79, ac.getTemp());
 }
 
 TEST(TestTrotec3550Class, SwingV) {