diff --git a/src/devices/boiler.cpp b/src/devices/boiler.cpp
index 68adc92d9..f37199dae 100644
--- a/src/devices/boiler.cpp
+++ b/src/devices/boiler.cpp
@@ -568,6 +568,12 @@ Boiler::Boiler(uint8_t device_type, int8_t device_id, uint8_t product_id, const
                               FL_(auxHeaterOnly),
                               DeviceValueUOM::NONE,
                               MAKE_CF_CB(set_additionalHeaterOnly));
+        register_device_value(DeviceValueTAG::TAG_DEVICE_DATA,
+                              &auxHeater_,
+                              DeviceValueType::BOOL,
+                              FL_(auxHeater),
+                              DeviceValueUOM::NONE,
+                              MAKE_CF_CB(set_additionalHeater));
         register_device_value(DeviceValueTAG::TAG_DEVICE_DATA,
                               &addHeaterDelay_,
                               DeviceValueType::USHORT,
@@ -1502,8 +1508,9 @@ void Boiler::process_HpValve(std::shared_ptr<const Telegram> telegram) {
 // Boiler(0x08) -> All(0x00), ?(0x0491), data: 03 01 00 00 00 02 64 00 00 14 01 2C 00 0A 00 1E 00 1E 00 00 1E 0A 1E 05 05
 void Boiler::process_HpAdditionalHeater(std::shared_ptr<const Telegram> telegram) {
     has_update(telegram, auxHeaterOnly_, 1);
+    has_update(telegram, auxHeater_, 2);
     has_update(telegram, tempParMode_, 5);
-    has_update(telegram, addHeaterDelay_, 10);
+    // has_update(telegram, addHeaterDelay_, ?); // unknown position
 }
 
 // Settings AM200
@@ -2465,6 +2472,15 @@ bool Boiler::set_additionalHeaterOnly(const char * value, const int8_t id) {
     return false;
 }
 
+bool Boiler::set_additionalHeater(const char * value, const int8_t id) {
+    bool v;
+    if (Helpers::value2bool(value, v)) {
+        write_command(0x491, 2, v ? 1 : 0, 0x491);
+        return true;
+    }
+    return false;
+}
+
 bool Boiler::set_tempParMode(const char * value, const int8_t id) {
     int v;
     if (Helpers::value2temperature(value, v)) {
diff --git a/src/devices/boiler.h b/src/devices/boiler.h
index 1bb8cfe41..cf85389d0 100644
--- a/src/devices/boiler.h
+++ b/src/devices/boiler.h
@@ -243,6 +243,7 @@ class Boiler : public EMSdevice {
     uint8_t  releaseWait_;   // pos 15: Boiler release wait time (min)
 
     uint8_t  auxHeaterOnly_;
+    uint8_t  auxHeater_;
     uint16_t addHeaterDelay_;
     int8_t   minTempSilent_;
     int8_t   tempParMode_;
@@ -389,6 +390,7 @@ class Boiler : public EMSdevice {
     }
     bool set_minTempSilent(const char * value, const int8_t id);
     bool set_additionalHeaterOnly(const char * value, const int8_t id);
+    bool set_additionalHeater(const char * value, const int8_t id);
     bool set_additionalHeaterDelay(const char * value, const int8_t id);
     bool set_tempParMode(const char * value, const int8_t id);
 
diff --git a/src/locale_translations.h b/src/locale_translations.h
index 2d2f67a96..effb1f799 100644
--- a/src/locale_translations.h
+++ b/src/locale_translations.h
@@ -368,6 +368,7 @@ MAKE_PSTR_LIST(maxHeatComp, "maxheatcomp", "heat limit compressor", "Heizgrenze
 MAKE_PSTR_LIST(maxHeatHeat, "maxheatheat", "heat limit heating", "Heizgrenze Heizen", "heat limit heating", "heat limit heating", "limit ciepła dla ogrzewania", "maks varmegrense oppvarming", "limite chaleur chauffage")
 MAKE_PSTR_LIST(maxHeatDhw, "maxheatdhw", "heat limit dhw", "Heizgrenze Warmwasser", "heat limit dhw", "heat limit dhw", "limit ciepła dla c.w.u.", "varmegrense varmtvann", "limite chaleur ecs")
 
+MAKE_PSTR_LIST(auxHeater, "auxheater", "auxilliary heater", "Zusatzheizer")
 MAKE_PSTR_LIST(auxHeaterOnly, "auxheateronly", "auxilliary heater only", "nur Zusatzheizer")
 MAKE_PSTR_LIST(addHeaterDelay, "addheaterdelay", "additional heater on delay", "Zusatzheizer Einschaltverzögerung")
 MAKE_PSTR_LIST(minTempSilent, "mintempsilent", "min. outside temp. for silent mode", "Minimale Aussentemperatur Silentmodus")