diff --git a/owrx/modes.py b/owrx/modes.py
index b2132c6b..c67dfddb 100644
--- a/owrx/modes.py
+++ b/owrx/modes.py
@@ -158,6 +158,7 @@ class Modes(object):
             underlying=["nfm"],
             bandpass=Bandpass(-6000, 6000),
             requirements=["flex"],
+            service=True,
             squelch=False,
         ),
         DigitalMode("cwdecoder", "CWDecoder", underlying=["usb"]),
diff --git a/owrx/multimon.py b/owrx/multimon.py
index edbcfaab..6a672b4d 100644
--- a/owrx/multimon.py
+++ b/owrx/multimon.py
@@ -16,6 +16,8 @@ class MultimonParser(ThreadModule):
         self.frequency = 0
         self.data      = bytearray(b'')
         self.file      = None
+        self.maxLines  = 10000
+        self.cntLines  = 0
         super().__init__()
 
     def __del__(self):
@@ -42,17 +44,27 @@ class MultimonParser(ThreadModule):
             self.fileName = Storage().getFilePath(fileName + ".txt")
             logger.debug("Opening log file '%s'..." % self.fileName)
             self.file = open(self.fileName, "wb")
+            self.cntLines = 0
 
         except Exception as exptn:
             logger.debug("Exception opening file: %s" % str(exptn))
             self.file = None
 
     def writeFile(self, data):
+        # If no file open, create and open a new file
+        if self.file is None:
+            self.newFile(Storage().makeFileName("MON-{0}", self.frequency))
+        # If file open now...
         if self.file is not None:
+            # Write new line into the file
             try:
                 self.file.write(data)
             except Exception:
                 pass
+            # No more than maxLines per file
+            self.cntLines = self.cntLines + 1
+            if self.cntLines >= self.maxLines:
+                self.closeFile()
 
     def getInputFormat(self) -> Format:
         return Format.CHAR
diff --git a/owrx/service/__init__.py b/owrx/service/__init__.py
index c5dd673f..af098551 100644
--- a/owrx/service/__init__.py
+++ b/owrx/service/__init__.py
@@ -318,6 +318,9 @@ class ServiceHandler(SdrSourceEventClient):
         elif mod == "fax":
             from csdr.chain.digimodes import FaxDemodulator
             return FaxDemodulator(service=True)
+        elif mod == "flex":
+            from csdr.chain.multimon import FlexDemodulator
+            return FlexDemodulator(service=True)
 
         raise ValueError("unsupported service modulation: {}".format(mod))