diff --git a/soft/thermostat/inc/edit_dlg.h b/soft/thermostat/inc/edit_dlg.h
index b0a142b..343a001 100644
--- a/soft/thermostat/inc/edit_dlg.h
+++ b/soft/thermostat/inc/edit_dlg.h
@@ -15,6 +15,7 @@
 #include <QSpinBox>
 #include <QDateTime>
 #include <QVBoxLayout>
+#include <QPushButton>
 #include <QDoubleSpinBox>
 
 #include "settings.h"
@@ -33,6 +34,7 @@ private:
 	void set_font(QWidget *widget);
 	QHBoxLayout *add_prog_layout(int idx);
 
+	QPushButton *m_add_btn;
 	QDoubleSpinBox m_default_temperature;
 	QVBoxLayout *m_progsLayout;
 	QVector<struct Program> m_progs;
diff --git a/soft/thermostat/src/edit_dlg.cpp b/soft/thermostat/src/edit_dlg.cpp
index bf9330e..3a1f3a0 100644
--- a/soft/thermostat/src/edit_dlg.cpp
+++ b/soft/thermostat/src/edit_dlg.cpp
@@ -26,6 +26,9 @@
 #define SPIN_ARROW_H 50
 #define SPIN_FONT_SZ 20
 
+// otherwise, the Rpi screen is too small
+#define MAX_PROGRAMS 4
+
 EditDlg::EditDlg(int idx, QWidget *parent, Qt::WindowFlags f) : QWidget(parent, f)
 {
 	Settings *s = Settings::getInstance();
@@ -63,8 +66,8 @@ EditDlg::EditDlg(int idx, QWidget *parent, Qt::WindowFlags f) : QWidget(parent,
 	upperLayout->addWidget(room_name);
 	upperLayout->addWidget(&m_default_temperature);
 
+	m_add_btn = new QPushButton(tr("Add"), this);
 	QPushButton *ok_btn = new QPushButton(tr("Ok"), this);
-	QPushButton *add_btn = new QPushButton(tr("Add"), this);
 	QPushButton *cancel_btn = new QPushButton(tr("Cancel"), this);
 
 
@@ -73,21 +76,23 @@ EditDlg::EditDlg(int idx, QWidget *parent, Qt::WindowFlags f) : QWidget(parent,
 						QSizePolicy::PushButton);
 
 	set_font(ok_btn);
-	set_font(add_btn);
+	set_font(m_add_btn);
 	set_font(cancel_btn);
 
 	ok_btn->setSizePolicy(*szPolicy);
-	add_btn->setSizePolicy(*szPolicy);
+	m_add_btn->setSizePolicy(*szPolicy);
 	cancel_btn->setSizePolicy(*szPolicy);
 
+	m_add_btn->setEnabled(m_progs.count() < MAX_PROGRAMS);
+
 	connect(ok_btn, SIGNAL(clicked(void)), this, SLOT(save(void)));
-	connect(add_btn, SIGNAL(clicked(void)), this, SLOT(add(void)));
+	connect(m_add_btn, SIGNAL(clicked(void)), this, SLOT(add(void)));
 	connect(cancel_btn, SIGNAL(clicked(void)), this, SLOT(reject(void)));
 
 	QHBoxLayout *btnLayout = new QHBoxLayout;
 
 	btnLayout->addWidget(cancel_btn);
-	btnLayout->addWidget(add_btn);
+	btnLayout->addWidget(m_add_btn);
 	btnLayout->addWidget(ok_btn);
 
 	QVBoxLayout *topLayout = new QVBoxLayout;
@@ -284,6 +289,8 @@ void EditDlg::add(void)
 
 	layout = add_prog_layout(idx);
 	m_progsLayout->addLayout(layout);
+
+	m_add_btn->setEnabled(m_progs.count() < MAX_PROGRAMS);
 }
 
 void EditDlg::delete_prog_clicked(void)
@@ -357,6 +364,8 @@ void EditDlg::delete_prog_clicked(void)
 			}
 		}
 	}
+
+	m_add_btn->setEnabled(m_progs.count() < MAX_PROGRAMS);
 }
 
 void EditDlg::edit_prog_clicked(void)