diff --git a/lib/Gateway.js b/lib/Gateway.js
index 9f982b31011..a959bef7735 100755
--- a/lib/Gateway.js
+++ b/lib/Gateway.js
@@ -1155,8 +1155,8 @@ Gateway.prototype.discoverDevice = function (node, hassDevice) {
  */
 Gateway.prototype.discoverClimates = function (node) {
   // https://github.com/zwave-js/node-zwave-js/blob/master/packages/config/config/deviceClasses.json#L177
+  // check if device it's a thermostat
   if (!node.deviceClass || node.deviceClass.generic !== 0x08) {
-    // it's a thermostat
     return
   }
 
@@ -1168,6 +1168,7 @@ Gateway.prototype.discoverClimates = function (node) {
       return
     }
 
+    // arrays of strings valueIds (without the node prefix)
     const setpoints = []
     const temperatures = []
     const modes = []
@@ -1192,7 +1193,10 @@ Gateway.prototype.discoverClimates = function (node) {
       }
     }
 
+    // take the first as valid (there shouldn't be more then one)
     const modeId = modes[0]
+
+    // TODO: if the device supports multiple endpoints how could we identify the correct one to use?
     const temperatureId = temperatures[0]
 
     if (!temperatureId || !modeId) {
@@ -1204,12 +1208,12 @@ Gateway.prototype.discoverClimates = function (node) {
 
     const mode = node.values[modeId]
 
-    // [0, 1, 2] ---> ['off', 'heat', 'cold']
+    // [0, 1, 2 ... ] (['off', 'heat', 'cold', ...])
     const availableModes = mode.states.map(s => s.value)
 
-    // zwave modes: https://github.com/zwave-js/node-zwave-js/blob/master/packages/zwave-js/src/lib/commandclass/ThermostatModeCC.ts#L54
+    // Zwave modes: https://github.com/zwave-js/node-zwave-js/blob/master/packages/zwave-js/src/lib/commandclass/ThermostatModeCC.ts#L54
+    // Available hass modes: [“auto”, “off”, “cool”, “heat”, “dry”, “fan_only”]
     const hassModes = [
-      // Available hass modes: [“auto”, “off”, “cool”, “heat”, “dry”, “fan_only”]
       'off',
       'heat',
       'cool',
@@ -1228,6 +1232,7 @@ Gateway.prototype.discoverClimates = function (node) {
       undefined // manufacturer specific
     ]
 
+    // generic configuration
     const config = copy(hassCfg.thermostat)
 
     config.mode_map = {}
@@ -1239,13 +1244,15 @@ Gateway.prototype.discoverClimates = function (node) {
 
     // for all available modes update the modes map and setpoint topics
     for (const m of availableModes) {
+      if (hassModes[m] === undefined) continue
+
       config.mode_map[hassModes[m]] = availableModes[m]
       config.discovery_payload.modes.push(hassModes[m])
       if (m > 0) {
         // find the mode setpoint, ignore off
         const setId = setpoints.find(v => v.endsWith('-' + m))
-        if (setId) {
-          const setpoint = node.values[setId]
+        const setpoint = node.values[setId]
+        if (setpoint) {
           if (setpoint.propertyKey === 1) {
             config.default_setpoint = setId
           }