diff --git a/ramp/__init__.py b/ramp/__init__.py
index 3f23af7e..d3753eb8 100644
--- a/ramp/__init__.py
+++ b/ramp/__init__.py
@@ -13,7 +13,6 @@
     - random
 """
 
-
 from ramp._version import __version__
 from ramp.core.core import UseCase, User, Appliance
 from ramp.core.utils import yearly_pattern, get_day_type
diff --git a/ramp/core/core.py b/ramp/core/core.py
index e21047b2..2e69110b 100644
--- a/ramp/core/core.py
+++ b/ramp/core/core.py
@@ -1033,6 +1033,14 @@ def __init__(
         self.name = name
         self.number = number
         self.num_windows = num_windows
+
+        if func_time == 0:
+            warnings.warn(
+                UserWarning(
+                    f"Func_time of appliance '{self.name}' is defined as 0. Ignore if this is intended"
+                )
+            )
+
         self.func_time = func_time
         self.time_fraction_random_variability = time_fraction_random_variability
         self.func_cycle = func_cycle
@@ -1799,6 +1807,8 @@ def generate_load_profile(self, prof_i, peak_time_range, day_type, power):
             or (self.pref_index != 0 and self.user.rand_daily_pref != self.pref_index)
             # checks if the app is allowed in the given yearly behaviour pattern
             or self.wd_we_type not in [day_type, 2]
+            # skip if the app has a func_time of 0
+            or self.func_time == 0
         ):
             return
 
@@ -1845,7 +1855,7 @@ def generate_load_profile(self, prof_i, peak_time_range, day_type, power):
         ]
 
         tot_time = 0
-        while tot_time <= rand_time:
+        while tot_time <= rand_time and rand_time != 0:
             # one option could be to generate a lot of them at once
             indexes = self.rand_switch_on_window(
                 rand_time=rand_time,  # TODO maybe only consider rand_time-tot_time ...
diff --git a/tests/test_func_time_zero.py b/tests/test_func_time_zero.py
new file mode 100644
index 00000000..0cf1d0af
--- /dev/null
+++ b/tests/test_func_time_zero.py
@@ -0,0 +1,42 @@
+import numpy as np
+import pytest
+from ramp import UseCase, User
+
+
+def test_skip_when_func_time_zero():
+    # Generate test user and appliance
+    user = User(user_name="Test User", num_users=1)
+    appliance = user.add_appliance(
+        name="Test Appliance",
+        func_time=0,  # Set func_time to be 0
+        func_cycle=20,
+        time_fraction_random_variability=0.1,
+    )
+
+    # Add to use_case
+    use_case = UseCase(name="test_use_case", users=[user])
+
+    # Calculate peak time range for this use_case
+    peak_time_range = use_case.calc_peak_time_range()
+
+    # Generated one load profile of this appliance
+    power = 1000
+    appliance.generate_load_profile(
+        prof_i=0, peak_time_range=peak_time_range, day_type=0, power=power
+    )
+
+    # Check that no use of this appliance is simulated -> the appliances load profile is always smaller than it's power
+    # (Checking for the load_profile to always be 0 might be unreliable, since the RAMP core "marks" potential usage
+    # windows with small power values larger 0)
+    assert np.max(appliance.daily_use) < power
+
+
+def test_warning_when_func_time_zero():
+    user = User(user_name="Test User", num_users=1)
+    with pytest.warns():
+        appliance = user.add_appliance(
+            name="Test Appliance",
+            func_time=0,  # Set func_time to be 0
+            func_cycle=20,
+            time_fraction_random_variability=0.1,
+        )