diff --git a/Framework/Kernel/inc/MantidKernel/Unit.h b/Framework/Kernel/inc/MantidKernel/Unit.h
index 8c5c99ce06fd1355888298fb316f3407fb28640c..442ec3950324a0e08646b2f6947a7b3dd075aa2a 100644
--- a/Framework/Kernel/inc/MantidKernel/Unit.h
+++ b/Framework/Kernel/inc/MantidKernel/Unit.h
@@ -193,9 +193,6 @@ protected:
   void addConversion(std::string to, const double &factor,
                      const double &power = 1.0) const;
 
-  /// Removes all registered 'quick conversions'
-  void clearConversions() const;
-
   /// The unit values have been initialized
   bool initialized;
   /// l1 ::       The source-sample distance (in metres)
diff --git a/Framework/Kernel/src/Unit.cpp b/Framework/Kernel/src/Unit.cpp
index fddcf6f76696dc6f3b17aac1fc7aac207a3be034..66c5fc6b9ad15d78d348ca51cf1d36a8796c4378 100644
--- a/Framework/Kernel/src/Unit.cpp
+++ b/Framework/Kernel/src/Unit.cpp
@@ -103,12 +103,6 @@ void Unit::addConversion(std::string to, const double &factor,
   s_conversionFactors[unitID()][to] = std::make_pair(factor, power);
 }
 
-//---------------------------------------------------------------------------------------
-/** Removes all registered 'quick conversions' from the unit class on which this
- * method is called.
- */
-void Unit::clearConversions() const { s_conversionFactors.clear(); }
-
 //---------------------------------------------------------------------------------------
 /** Initialize the unit to perform conversion using singleToTof() and
  *singleFromTof()
@@ -1068,7 +1062,7 @@ DECLARE_UNIT(SpinEchoLength)
 
 const UnitLabel SpinEchoLength::label() const { return Symbol::Nanometre; }
 
-SpinEchoLength::SpinEchoLength() : Wavelength() { clearConversions(); }
+SpinEchoLength::SpinEchoLength() : Wavelength() { }
 
 void SpinEchoLength::init() {
   // Efixed must be set to something
@@ -1119,7 +1113,7 @@ DECLARE_UNIT(SpinEchoTime)
 
 const UnitLabel SpinEchoTime::label() const { return Symbol::Nanosecond; }
 
-SpinEchoTime::SpinEchoTime() : Wavelength() { clearConversions(); }
+SpinEchoTime::SpinEchoTime() : Wavelength() { }
 
 void SpinEchoTime::init() {
   // Efixed must be set to something