diff --git a/src/cmfd_execute.F90 b/src/cmfd_execute.F90
index 8395165f95..ccac60a140 100644
--- a/src/cmfd_execute.F90
+++ b/src/cmfd_execute.F90
@@ -52,7 +52,7 @@ contains
     write(108,*) cmfd % dhat
 
     ! write cmfd object to hdf5 file
-    call write_hdf5()
+!   call write_hdf5()
 
     ! solve diffusion equation
     call cmfd_solver()
diff --git a/src/main.F90 b/src/main.F90
index 55aa3db2f2..778bd62b6b 100644
--- a/src/main.F90
+++ b/src/main.F90
@@ -67,6 +67,9 @@ program main
        call run_problem()
     end if
 
+    ! run diffusion
+    call execute_cmfd()
+
     ! finalize run
     call finalize_run()