diff --git a/Arduino/BTCDieselHeater/src/Utility/NVCore.cpp b/Arduino/BTCDieselHeater/src/Utility/NVCore.cpp
new file mode 100644
index 0000000..f7975a9
--- /dev/null
+++ b/Arduino/BTCDieselHeater/src/Utility/NVCore.cpp
@@ -0,0 +1,133 @@
+/*
+ * This file is part of the "bluetoothheater" distribution 
+ * (https://gitlab.com/mrjones.id.au/bluetoothheater) 
+ *
+ * Copyright (C) 2018  Ray Jones <ray@mrjones.id.au>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ * 
+ */
+
+#include <Arduino.h>
+#include "NVCore.h"
+#include "DebugPort.h"
+
+
+bool 
+CESP32_NVStorage::validatedLoad(const char* key, char* val, int maxlen, const char* defVal)
+{
+  char probe[128];
+  bool retval = true;
+  strcpy(probe, "TestPresence");
+  int len = preferences.getString(key, probe, 127);
+  if(len == 0 || strcmp(probe, "TestPresence") == 0) {
+    preferences.putString(key, defVal);
+    DebugPort.printf("CESP32HeaterStorage::validatedLoad<char*> default installed %s=%s", key, defVal);
+    retval = false;
+  }
+  preferences.getString(key, val, maxlen);
+  val[maxlen] = 0;  // ensure null terminated
+  return retval;
+}
+
+bool
+CESP32_NVStorage::validatedLoad(const char* key, uint8_t& val, int defVal, std::function<bool(uint8_t, uint8_t, uint8_t)> validator, int min, int max, uint8_t mask)
+{
+  val = preferences.getUChar(key, defVal);
+  if(!validator(val & mask, min, max)) {
+
+    DebugPort.printf("CESP32HeaterStorage::validatedLoad<uint8_t> invalid read %s=%d", key, val);
+    DebugPort.printf(" validator(%d,%d) reset to %d\r\n", min, max, defVal);
+
+    val = defVal;
+    preferences.putUChar(key, val);
+    return false;
+  }
+  return true;
+}
+
+bool
+CESP32_NVStorage::validatedLoad(const char* key, int8_t& val, int defVal, std::function<bool(int8_t, int8_t, int8_t)> validator, int min, int max)
+{
+  val = preferences.getChar(key, defVal);
+  if(!validator(val, min, max)) {
+
+    DebugPort.printf("CESP32HeaterStorage::validatedLoad<int8_t> invalid read %s=%d", key, val);
+    DebugPort.printf(" validator(%d,%d) reset to %d\r\n", min, max, defVal);
+
+    val = defVal;
+    preferences.putChar(key, val);
+    return false;
+  }
+  return true;
+}
+
+bool
+CESP32_NVStorage::validatedLoad(const char* key, uint16_t& val, int defVal, std::function<bool(uint16_t, uint16_t, uint16_t)> validator, int min, int max)
+{
+  val = preferences.getUShort(key, defVal);
+  if(!validator(val, min, max)) {
+
+    DebugPort.printf("CESP32HeaterStorage::validatedLoad<uint16_t> invalid read %s=%d", key, val);
+    DebugPort.printf(" validator(%d,%d) reset to %d\r\n", min, max, defVal);
+
+    val = defVal;
+    preferences.putUShort(key, val);
+    return false;
+  }
+  return true;
+}
+
+bool
+CESP32_NVStorage::validatedLoad(const char* key, long& val, long defVal, std::function<bool(long, long, long)> validator, long min, long max)
+{
+  val = preferences.getLong(key, defVal);
+  if(!validator(val, min, max)) {
+
+    DebugPort.printf("CESP32HeaterStorage::validatedLoad<long> invalid read %s=%ld", key, val);
+    DebugPort.printf(" validator(%ld,%ld) reset to %ld\r\n", min, max, defVal);
+
+    val = defVal;
+    preferences.putLong(key, val);
+    return false;
+  }
+  return true;
+}
+
+bool u8inBounds(uint8_t test, uint8_t minLim, uint8_t maxLim)
+{
+  return (test >= minLim) && (test <= maxLim);
+}
+
+bool s8inBounds(int8_t test, int8_t minLim, int8_t maxLim)
+{
+  return (test >= minLim) && (test <= maxLim);
+}
+
+bool u8Match2(uint8_t test, uint8_t test1, uint8_t test2)
+{
+  return (test == test1) || (test == test2);
+}
+
+bool u16inBounds(uint16_t test, uint16_t minLim, uint16_t maxLim)
+{
+  return (test >= minLim) && (test <= maxLim);
+}
+
+bool s32inBounds(long test, long minLim, long maxLim)
+{
+  return (test >= minLim) && (test <= maxLim);
+}
+
+
diff --git a/Arduino/BTCDieselHeater/src/Utility/NVCore.h b/Arduino/BTCDieselHeater/src/Utility/NVCore.h
new file mode 100644
index 0000000..38d0fe6
--- /dev/null
+++ b/Arduino/BTCDieselHeater/src/Utility/NVCore.h
@@ -0,0 +1,58 @@
+/*
+ * This file is part of the "bluetoothheater" distribution 
+ * (https://gitlab.com/mrjones.id.au/bluetoothheater) 
+ *
+ * Copyright (C) 2018  Ray Jones <ray@mrjones.id.au>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef __BTC_NV_CORE_H__
+#define __BTC_NV_CORE_H__
+
+#include <Preferences.h>
+#include <functional>
+
+bool u8inBounds(uint8_t test, uint8_t minLim, uint8_t maxLim);
+bool s8inBounds(int8_t test, int8_t minLim, int8_t maxLim);
+bool u8Match2(uint8_t test, uint8_t test1, uint8_t test2);
+bool u16inBounds(uint16_t test, uint16_t minLim, uint16_t maxLim);
+bool s32inBounds(long test, long minLim, long maxLim);
+bool thermoMethodinBounds(uint8_t test, uint8_t minLim, uint8_t maxLim);
+
+class CNVStorage {
+  public:
+    CNVStorage() {};
+    virtual ~CNVStorage() {};
+    virtual void init() = 0;
+    virtual void load() = 0;
+    virtual void save() = 0;
+    virtual bool valid() = 0;
+};
+
+class CESP32_NVStorage {
+protected:
+  Preferences preferences;
+protected:
+  bool validatedLoad(const char* key, int8_t& val, int defVal, std::function<bool(int8_t, int8_t, int8_t)> validator, int min, int max);
+  bool validatedLoad(const char* key, uint8_t& val, int defVal, std::function<bool(uint8_t, uint8_t, uint8_t)> validator, int min, int max, uint8_t mask=0xff);
+  bool validatedLoad(const char* key, uint16_t& val, int defVal, std::function<bool(uint16_t, uint16_t, uint16_t)> validator, int min, int max);
+  bool validatedLoad(const char* key, long& val, long defVal, std::function<bool(long, long, long)> validator, long min, long max);
+  bool validatedLoad(const char* key, char* val, int maxlen, const char* defVal);
+};
+
+
+#endif // __BTC_NV_CORE_H__
+