diff --git a/.gitignore b/.gitignore
index 2de9dd40e5..11a80a647c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -54,6 +54,7 @@ htmlcov/
 .esphome
 nosetests.xml
 coverage.xml
+cov.xml
 *.cover
 .hypothesis/
 .pytest_cache/
diff --git a/esphome/wizard.py b/esphome/wizard.py
index b00f6d2b01..b1a0b17072 100644
--- a/esphome/wizard.py
+++ b/esphome/wizard.py
@@ -142,7 +142,7 @@ def wizard(path):
     if os.path.exists(path):
         safe_print("Uh oh, it seems like {} already exists, please delete that file first "
                    "or chose another configuration file.".format(color('cyan', path)))
-        return 1
+        return 2
     safe_print("Hi there!")
     sleep(1.5)
     safe_print("I'm the wizard of ESPHome :)")
@@ -162,14 +162,15 @@ def wizard(path):
     safe_print()
     sleep(1)
     name = input(color("bold_white", "(name): "))
+
     while True:
         try:
             name = cv.valid_name(name)
             break
         except vol.Invalid:
             safe_print(color("red", "Oh noes, \"{}\" isn't a valid name. Names can only include "
-                                    "numbers, letters and underscores.".format(name)))
-            name = strip_accents(name).replace(' ', '_')
+                                    "numbers, lower-case letters and underscores.".format(name)))
+            name = strip_accents(name).lower().replace(' ', '_')
             name = ''.join(c for c in name if c in cv.ALLOWED_NAME_CHARS)
             safe_print("Shall I use \"{}\" as the name instead?".format(color('cyan', name)))
             sleep(0.5)
diff --git a/tests/unit_tests/test_wizard.py b/tests/unit_tests/test_wizard.py
new file mode 100644
index 0000000000..2baff80edd
--- /dev/null
+++ b/tests/unit_tests/test_wizard.py
@@ -0,0 +1,389 @@
+""" Tests for the wizard.py file """
+
+import esphome.wizard as wz
+import pytest
+from esphome.pins import ESP8266_BOARD_PINS
+from mock import MagicMock
+
+
+@pytest.fixture
+def default_config():
+    return {
+        "name": "test_name",
+        "platform": "test_platform",
+        "board": "test_board",
+        "ssid": "test_ssid",
+        "psk": "test_psk",
+        "password": ""
+    }
+
+
+@pytest.fixture
+def wizard_answers():
+    return [
+        "test_node",  # Name of the node
+        "ESP8266",  # platform
+        "nodemcuv2",  # board
+        "SSID",  # ssid
+        "psk",  # wifi password
+        "ota_pass",  # ota password
+    ]
+
+
+def test_sanitize_quotes_replaces_with_escaped_char():
+    """
+    The sanitize_quotes function should replace double quotes with their escaped equivalents
+    """
+    # Given
+    input_str = "\"key\": \"value\""
+
+    # When
+    output_str = wz.sanitize_double_quotes(input_str)
+
+    # Then
+    assert output_str == "\\\"key\\\": \\\"value\\\""
+
+
+def test_config_file_fallback_ap_includes_descriptive_name(default_config):
+    """
+    The fallback AP should include the node and a descriptive name
+    """
+    # Given
+    default_config["name"] = "test_node"
+
+    # When
+    config = wz.wizard_file(**default_config)
+
+    # Then
+    assert f"ssid: \"Test Node Fallback Hotspot\"" in config
+
+
+def test_config_file_fallback_ap_name_less_than_32_chars(default_config):
+    """
+    The fallback AP name must be less than 32 chars.
+    Since it is composed of the node name and "Fallback Hotspot" this can be too long and needs truncating
+    """
+    # Given
+    default_config["name"] = "a_very_long_name_for_this_node"
+
+    # When
+    config = wz.wizard_file(**default_config)
+
+    # Then
+    assert f"ssid: \"A Very Long Name For This Node\"" in config
+
+
+def test_config_file_should_include_ota(default_config):
+    """
+    The Over-The-Air update should be enabled by default
+    """
+    # Given
+
+    # When
+    config = wz.wizard_file(**default_config)
+
+    # Then
+    assert "ota:" in config
+
+
+def test_config_file_should_include_ota_when_password_set(default_config):
+    """
+    The Over-The-Air update should be enabled when a password is set
+    """
+    # Given
+    default_config["password"] = "foo"
+
+    # When
+    config = wz.wizard_file(**default_config)
+
+    # Then
+    assert "ota:" in config
+
+
+def test_wizard_write_sets_platform(default_config, tmp_path, monkeypatch):
+    """
+    If the platform is not explicitly set, use "ESP8266" if the board is one of the ESP8266 boards
+    """
+    # Given
+    monkeypatch.setattr(wz, "write_file", MagicMock())
+
+    # When
+    wz.wizard_write(tmp_path, **default_config)
+
+    # Then
+    generated_config = wz.write_file.call_args.args[1]
+    assert f"platform: {default_config['platform']}" in generated_config
+
+
+def test_wizard_write_defaults_platform_from_board_esp8266(default_config, tmp_path, monkeypatch):
+    """
+    If the platform is not explicitly set, use "ESP8266" if the board is one of the ESP8266 boards
+    """
+    # Given
+    del default_config["platform"]
+    default_config["board"] = [*ESP8266_BOARD_PINS][0]
+
+    monkeypatch.setattr(wz, "write_file", MagicMock())
+
+    # When
+    wz.wizard_write(tmp_path, **default_config)
+
+    # Then
+    generated_config = wz.write_file.call_args.args[1]
+    assert "platform: ESP8266" in generated_config
+
+
+def test_wizard_write_defaults_platform_from_board_esp32(default_config, tmp_path, monkeypatch):
+    """
+    If the platform is not explicitly set, use "ESP32" if the board is not one of the ESP8266 boards
+    """
+    # Given
+    del default_config["platform"]
+    default_config["board"] = "foo"
+
+    monkeypatch.setattr(wz, "write_file", MagicMock())
+
+    # When
+    wz.wizard_write(tmp_path, **default_config)
+
+    # Then
+    generated_config = wz.write_file.call_args.args[1]
+    assert "platform: ESP32" in generated_config
+
+
+def test_safe_print_step_prints_step_number_and_description(monkeypatch):
+    """
+    The safe_print_step function prints the step number and the passed description
+    """
+    # Given
+    monkeypatch.setattr(wz, "safe_print", MagicMock())
+    monkeypatch.setattr(wz, "sleep", lambda time: 0)
+
+    step_num = 22
+    step_desc = "foobartest"
+
+    # When
+    wz.safe_print_step(step_num, step_desc)
+
+    # Then
+    # Collect arguments to all safe_print() calls (substituting "" for any empty ones)
+    all_args = [call.args[0] if len(call.args) else "" for call in wz.safe_print.call_args_list]
+
+    assert any(step_desc == arg for arg in all_args)
+    assert any(f"STEP {step_num}" in arg for arg in all_args)
+
+
+def test_default_input_uses_default_if_no_input_supplied(monkeypatch):
+    """
+    The default_input() function should return the supplied default value if the user doesn't enter anything
+    """
+
+    # Given
+    monkeypatch.setattr("builtins.input", lambda _: "")
+    default_string = "foobar"
+
+    # When
+    retval = wz.default_input("", default_string)
+
+    # Then
+    assert retval == default_string
+
+
+def test_default_input_uses_user_supplied_value(monkeypatch):
+    """
+    The default_input() function should return the value that the user enters
+    """
+
+    # Given
+    user_input = "A value"
+    monkeypatch.setattr("builtins.input", lambda _: user_input)
+    default_string = "foobar"
+
+    # When
+    retval = wz.default_input("", default_string)
+
+    # Then
+    assert retval == user_input
+
+
+def test_strip_accents_removes_diacritics():
+    """
+    The strip_accents() function should remove diacritics (umlauts)
+    """
+
+    # Given
+    input_str = u"Kühne"
+    expected_str = "Kuhne"
+
+    # When
+    output_str = wz.strip_accents(input_str)
+
+    # Then
+    assert output_str == expected_str
+
+
+def test_wizard_rejects_path_with_invalid_extension():
+    """
+    The wizard should reject config files that are not yaml
+    """
+
+    # Given
+    config_file = "test.json"
+
+    # When
+    retval = wz.wizard(config_file)
+
+    # Then
+    assert retval == 1
+
+
+def test_wizard_rejects_existing_files(tmpdir):
+    """
+    The wizard should reject any configuration file that already exists
+    """
+
+    # Given
+    config_file = tmpdir.join("test.yaml")
+    config_file.write("")
+
+    # When
+    retval = wz.wizard(str(config_file))
+
+    # Then
+    assert retval == 2
+
+
+def test_wizard_accepts_default_answers_esp8266(tmpdir, monkeypatch, wizard_answers):
+    """
+    The wizard should accept the given default answers for esp8266
+    """
+
+    # Given
+    config_file = tmpdir.join("test.yaml")
+    input_mock = MagicMock(side_effect=wizard_answers)
+    monkeypatch.setattr("builtins.input", input_mock)
+    monkeypatch.setattr(wz, "safe_print", lambda t=None: 0)
+    monkeypatch.setattr(wz, "sleep", lambda _: 0)
+    monkeypatch.setattr(wz, "wizard_write",  MagicMock())
+
+    # When
+    retval = wz.wizard(str(config_file))
+
+    # Then
+    assert retval == 0
+
+
+def test_wizard_accepts_default_answers_esp32(tmpdir, monkeypatch, wizard_answers):
+    """
+    The wizard should accept the given default answers for esp32
+    """
+
+    # Given
+    wizard_answers[1] = "ESP32"
+    wizard_answers[2] = "nodemcu-32s"
+    config_file = tmpdir.join("test.yaml")
+    input_mock = MagicMock(side_effect=wizard_answers)
+    monkeypatch.setattr("builtins.input", input_mock)
+    monkeypatch.setattr(wz, "safe_print", lambda t=None: 0)
+    monkeypatch.setattr(wz, "sleep", lambda _: 0)
+    monkeypatch.setattr(wz, "wizard_write",  MagicMock())
+
+    # When
+    retval = wz.wizard(str(config_file))
+
+    # Then
+    assert retval == 0
+
+
+def test_wizard_offers_better_node_name(tmpdir, monkeypatch, wizard_answers):
+    """
+    When the node name does not conform, a better alternative is offered
+    * Removes special chars
+    * Replaces spaces with underscores
+    * Converts all uppercase letters to lowercase
+    """
+
+    # Given
+    wizard_answers[0] = "Küche #2"
+    expected_name = "kuche_2"
+    monkeypatch.setattr(wz, "default_input", MagicMock(side_effect=lambda _, default: default))
+
+    config_file = tmpdir.join("test.yaml")
+    input_mock = MagicMock(side_effect=wizard_answers)
+    monkeypatch.setattr("builtins.input", input_mock)
+    monkeypatch.setattr(wz, "safe_print", lambda t=None: 0)
+    monkeypatch.setattr(wz, "sleep", lambda _: 0)
+    monkeypatch.setattr(wz, "wizard_write",  MagicMock())
+
+    # When
+    retval = wz.wizard(str(config_file))
+
+    # Then
+    assert retval == 0
+    assert wz.default_input.call_args.args[1] == expected_name
+
+
+def test_wizard_requires_correct_platform(tmpdir, monkeypatch, wizard_answers):
+    """
+    When the platform is not either esp32 or esp8266, the wizard should reject it
+    """
+
+    # Given
+    wizard_answers.insert(1, "foobar")  # add invalid entry for platform
+
+    config_file = tmpdir.join("test.yaml")
+    input_mock = MagicMock(side_effect=wizard_answers)
+    monkeypatch.setattr("builtins.input", input_mock)
+    monkeypatch.setattr(wz, "safe_print", lambda t=None: 0)
+    monkeypatch.setattr(wz, "sleep", lambda _: 0)
+    monkeypatch.setattr(wz, "wizard_write",  MagicMock())
+
+    # When
+    retval = wz.wizard(str(config_file))
+
+    # Then
+    assert retval == 0
+
+
+def test_wizard_requires_correct_board(tmpdir, monkeypatch, wizard_answers):
+    """
+    When the board is not a valid esp8266 board, the wizard should reject it
+    """
+
+    # Given
+    wizard_answers.insert(2, "foobar")  # add an invalid entry for board
+
+    config_file = tmpdir.join("test.yaml")
+    input_mock = MagicMock(side_effect=wizard_answers)
+    monkeypatch.setattr("builtins.input", input_mock)
+    monkeypatch.setattr(wz, "safe_print", lambda t=None: 0)
+    monkeypatch.setattr(wz, "sleep", lambda _: 0)
+    monkeypatch.setattr(wz, "wizard_write",  MagicMock())
+
+    # When
+    retval = wz.wizard(str(config_file))
+
+    # Then
+    assert retval == 0
+
+
+def test_wizard_requires_valid_ssid(tmpdir, monkeypatch, wizard_answers):
+    """
+    When the board is not a valid esp8266 board, the wizard should reject it
+    """
+
+    # Given
+    wizard_answers.insert(3, "")  # add an invalid entry for ssid
+
+    config_file = tmpdir.join("test.yaml")
+    input_mock = MagicMock(side_effect=wizard_answers)
+    monkeypatch.setattr("builtins.input", input_mock)
+    monkeypatch.setattr(wz, "safe_print", lambda t=None: 0)
+    monkeypatch.setattr(wz, "sleep", lambda _: 0)
+    monkeypatch.setattr(wz, "wizard_write",  MagicMock())
+
+    # When
+    retval = wz.wizard(str(config_file))
+
+    # Then
+    assert retval == 0