diff --git a/.gitignore b/.gitignore
index 6d729a0..7c0acaf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 .pio
 .vscode
 build/*.bin
+build/*.elf
 data/*
 secrets.ini
 node_modules
diff --git a/src/HaHelper.h b/src/HaHelper.h
index ea5198e..2af66be 100644
--- a/src/HaHelper.h
+++ b/src/HaHelper.h
@@ -876,8 +876,8 @@ public:
     doc[FPSTR(HA_VALUE_TEMPLATE)] = F("{{ value_json.equitherm.k_factor|float(0)|round(2) }}");
     doc[FPSTR(HA_COMMAND_TOPIC)] = this->setSettingsTopic.c_str();
     doc[FPSTR(HA_COMMAND_TEMPLATE)] = F("{\"equitherm\": {\"k_factor\" : {{ value }}}}");
-    doc[FPSTR(HA_MIN)] = 0;
-    doc[FPSTR(HA_MAX)] = 10;
+    doc[FPSTR(HA_MIN)] = -15;
+    doc[FPSTR(HA_MAX)] = 15;
     doc[FPSTR(HA_STEP)] = 0.01f;
     doc[FPSTR(HA_MODE)] = FPSTR(HA_MODE_BOX);
     doc[FPSTR(HA_EXPIRE_AFTER)] = this->expireAfter;
diff --git a/src_data/pages/settings.html b/src_data/pages/settings.html
index 69b6bbc..297126a 100644
--- a/src_data/pages/settings.html
+++ b/src_data/pages/settings.html
@@ -283,7 +283,7 @@
 
                 <label>
                   <span data-i18n>settings.equitherm.k</span>
-                  <input type="number" inputmode="decimal" name="equitherm[k_factor]" min="0" max="10" step="0.01" required>
+                  <input type="number" inputmode="decimal" name="equitherm[k_factor]" min="-15" max="5" step="0.01" required>
                 </label>
 
                 <label>