diff --git a/tcl/drivers/dil12.tcl b/tcl/drivers/dil12.tcl
index 3199b58..d5169ab 100644
--- a/tcl/drivers/dil12.tcl
+++ b/tcl/drivers/dil12.tcl
@@ -257,6 +257,9 @@ proc stdConfig::dil12 args {
       prop label "remove mixture status"
       prop check dil12::check_removephase
       prop write stdSct::completeUpdate
+
+      node ignore_vti_temp -int par 0
+      prop enum 1
     }
   }
   hset $name/heatermode 0
@@ -992,10 +995,15 @@ proc dil12::autostep {phase init} {
       dil12::openvalves v1 v6 v12 v13 vm_open
 
       sorb mode 0
-      dil12::set_VtiT 1.25
       hset [sct]/onekstate 0
       nv set [silent 5 hvali [sct]/circulateflow]
-      nv 2 ;# auto
+      if {[hval [sct]/ignore_vti_temp]} {
+        dil12::set_VtiT 0
+        nv 1 ;# controlled
+      } else {
+        dil12::set_VtiT 1.25
+        nv 2 ;# auto
+      }
       dil12::msg ""
     }
     circulate {
@@ -1034,7 +1042,11 @@ proc dil12::autostep {phase init} {
               sct optimize [clock seconds]
               clientput "reduced VTI flow to [hvali [sct]/circulateflow]"
               nv set $circulateflow
-              nv 2 ;# auto
+              if {[hval [sct]/ignore_vti_temp]} {
+                nv 1 ;# controlled
+              } else {
+                nv 2 ;# auto
+              }
             }
           } 
         }