diff --git a/applications/solvers/multiphase/reactingEulerFoam/phaseSystems/populationBalanceModel/populationBalanceModel/populationBalanceModel.C b/applications/solvers/multiphase/reactingEulerFoam/phaseSystems/populationBalanceModel/populationBalanceModel/populationBalanceModel.C
index 4406d39eb..429c22386 100644
--- a/applications/solvers/multiphase/reactingEulerFoam/phaseSystems/populationBalanceModel/populationBalanceModel/populationBalanceModel.C
+++ b/applications/solvers/multiphase/reactingEulerFoam/phaseSystems/populationBalanceModel/populationBalanceModel/populationBalanceModel.C
@@ -1174,15 +1174,9 @@ void Foam::diameterModels::populationBalanceModel::solve()
         }
 
         int iCorr = 0;
-        scalar initialResidual = 0;
         scalar maxInitialResidual = 1;
 
-        while
-        (
-            maxInitialResidual > tolerance
-            &&
-            ++iCorr <= nCorr
-        )
+        while (++iCorr <= nCorr && maxInitialResidual > tolerance)
         {
             Info<< "populationBalance "
                 << this->name()
@@ -1194,6 +1188,8 @@ void Foam::diameterModels::populationBalanceModel::solve()
 
             dmdt();
 
+            maxInitialResidual = 0;
+
             forAll(sizeGroups_, i)
             {
                 sizeGroup& fi = *sizeGroups_[i];
@@ -1223,16 +1219,11 @@ void Foam::diameterModels::populationBalanceModel::solve()
                   - fvm::ddt(residualAlpha*rho, fi)
                 );
 
-                sizeGroupEqn.relax
-                (
-                    fi.mesh().equationRelaxationFactor("f")
-                );
-
-                initialResidual = sizeGroupEqn.solve().initialResidual();
+                sizeGroupEqn.relax();
 
                 maxInitialResidual = max
                 (
-                    initialResidual,
+                    sizeGroupEqn.solve().initialResidual(),
                     maxInitialResidual
                 );
             }
diff --git a/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/binaryBreakup/system/fvSolution b/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/binaryBreakup/system/fvSolution
index d55ba8675..a9900b504 100644
--- a/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/binaryBreakup/system/fvSolution
+++ b/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/binaryBreakup/system/fvSolution
@@ -66,7 +66,7 @@ relaxationFactors
 {
     equations
     {
-        f                  1.0;
+        "f.*"              1.0;
     }
 }
 
diff --git a/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/breakup/system/fvSolution b/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/breakup/system/fvSolution
index d55ba8675..a9900b504 100644
--- a/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/breakup/system/fvSolution
+++ b/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/breakup/system/fvSolution
@@ -66,7 +66,7 @@ relaxationFactors
 {
     equations
     {
-        f                  1.0;
+        "f.*"              1.0;
     }
 }
 
diff --git a/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/coalescence/system/fvSolution b/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/coalescence/system/fvSolution
index db2be3b84..4a326bba0 100644
--- a/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/coalescence/system/fvSolution
+++ b/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/coalescence/system/fvSolution
@@ -66,7 +66,7 @@ relaxationFactors
 {
     equations
     {
-        f                  1.0;
+        "f.*"              1.0;
     }
 }
 
diff --git a/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/simultaneousCoalescenceAndBreakup/system/fvSolution b/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/simultaneousCoalescenceAndBreakup/system/fvSolution
index d0808e00b..93a64fc55 100644
--- a/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/simultaneousCoalescenceAndBreakup/system/fvSolution
+++ b/test/multiphase/reactingMultiphaseEulerFoam/populationBalanceModeling/simultaneousCoalescenceAndBreakup/system/fvSolution
@@ -66,7 +66,7 @@ relaxationFactors
 {
     equations
     {
-        f                  1.0;
+        "f.*"              1.0;
     }
 }
 
diff --git a/test/multiphase/reactingTwoPhaseEulerFoam/populationBalanceModeling/drift/system/fvSolution b/test/multiphase/reactingTwoPhaseEulerFoam/populationBalanceModeling/drift/system/fvSolution
index d55ba8675..a9900b504 100644
--- a/test/multiphase/reactingTwoPhaseEulerFoam/populationBalanceModeling/drift/system/fvSolution
+++ b/test/multiphase/reactingTwoPhaseEulerFoam/populationBalanceModeling/drift/system/fvSolution
@@ -66,7 +66,7 @@ relaxationFactors
 {
     equations
     {
-        f                  1.0;
+        "f.*"              1.0;
     }
 }
 
diff --git a/test/multiphase/reactingTwoPhaseEulerFoam/populationBalanceModeling/negativeDrift/system/fvSolution b/test/multiphase/reactingTwoPhaseEulerFoam/populationBalanceModeling/negativeDrift/system/fvSolution
index d55ba8675..a9900b504 100644
--- a/test/multiphase/reactingTwoPhaseEulerFoam/populationBalanceModeling/negativeDrift/system/fvSolution
+++ b/test/multiphase/reactingTwoPhaseEulerFoam/populationBalanceModeling/negativeDrift/system/fvSolution
@@ -66,7 +66,7 @@ relaxationFactors
 {
     equations
     {
-        f                  1.0;
+        "f.*"              1.0;
     }
 }