diff --git a/package.json b/package.json
index 92c4113..ac9f552 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@vvzvlad/node-red-contrib-rn-combined-nodes",
-  "version": "0.2.10",
+  "version": "0.2.11",
   "description": "",
   "main": "index.js",
   "keywords": [
diff --git a/thermostat.js b/thermostat.js
index 1d884ac..7da1a24 100644
--- a/thermostat.js
+++ b/thermostat.js
@@ -11,17 +11,15 @@ module.exports = function(RED) {
         const HEAT_OFF_THRESHOLD = 0.2
         let debug = ""
 
-
-        context.set("pwm_timer", null);
-        context.set("pwm_period", 30*60*1000);
-        context.set("pwm_tick", 1000);
+        let pwm_timer = null
+        context.set("pwm_period", 10000) //30*60*1000)
+        context.set("pwm_tick", 1000)
 
         function manage_pwm(duty_cycle_percent) {
             if (duty_cycle_percent === -1) {
-                const pwm_timer = context.get("pwm_timer");
                 if (pwm_timer !== null) {
-                    clearInterval(pwm_timer);
-                    context.set("pwm_timer", null);
+                    clearInterval(pwm_timer)
+                    pwm_timer = null
                 }
                 return;
             }
@@ -29,11 +27,11 @@ module.exports = function(RED) {
             const pwm_duty_cycle = Math.max(0, Math.min(1, duty_cycle_percent / 100));
             context.set("pwm_duty_cycle", pwm_duty_cycle);
 
-            if (context.get("pwm_timer") === null) {
+            if (pwm_timer === null) {
                 let cycle_start_time = Date.now();
                 const pwm_tick = context.get("pwm_tick");
 
-                const pwm_timer = setInterval(() => {
+                pwm_timer = setInterval(() => {
                     const pwm_period = context.get("pwm_period");
                     const elapsed_time = Date.now() - cycle_start_time;
                     const on_time = pwm_period * pwm_duty_cycle;
@@ -49,8 +47,6 @@ module.exports = function(RED) {
                     }
 
                 }, pwm_tick);
-
-                context.set("pwm_timer", pwm_timer);
             }
         }