diff --git a/cfg/vf_cfg.py b/cfg/vf_cfg.py
index ad7e44b..29819e9 100644
--- a/cfg/vf_cfg.py
+++ b/cfg/vf_cfg.py
@@ -67,7 +67,7 @@ Mod('T_wall',
    )
 
 Mod('T',
-    'frappy_psi.picontrol.PI',
+    'frappy_psi.furnace.PI',
     'controlled Temperature',
     input = 'T_htr',
     output = 'out',
diff --git a/frappy_psi/furnace.py b/frappy_psi/furnace.py
index 6db7e3f..1a9f78b 100644
--- a/frappy_psi/furnace.py
+++ b/frappy_psi/furnace.py
@@ -20,7 +20,10 @@
 """interlocks for furnance"""
 
 import time
-from frappy.core import Module, Writable, Attached, Parameter, FloatRange, Readable, BoolType, ERROR, IDLE
+from frappy.core import Module, Writable, Attached, Parameter, FloatRange, Readable,\
+     BoolType, ERROR, IDLE
+from frappy_psi.picontrol import PImixin
+
 
 class Interlocks(Module):
     input = Attached(Readable, 'the input module')
@@ -45,5 +48,16 @@ class Interlocks(Module):
             return
         self.control.write_control_active(False)
         self.relais.write_target(False)
-        
-      
\ No newline at end of file
+
+
+class PI(PImixin, Writable):
+    input = Attached(Readable, 'the input module')
+    relais = Attached(Writable, 'the interlock relais', mandatory=False)
+
+    def read_value(self):
+        return self.input.value
+
+    def write_target(self, value):
+        super().write_target(value)
+        if self.relais:
+            self.relais.write_target(1)