diff --git a/src/fmu/ensemble/ensemble.py b/src/fmu/ensemble/ensemble.py
index b2604d43..fc778604 100644
--- a/src/fmu/ensemble/ensemble.py
+++ b/src/fmu/ensemble/ensemble.py
@@ -4,6 +4,7 @@
 import os
 import glob
 import logging
+import warnings
 
 import dateutil
 import pandas as pd
@@ -696,8 +697,8 @@ def load_smry(
         self,
         time_index="raw",
         column_keys=None,
-        stacked=True,
-        cache_eclsum=True,
+        stacked=None,
+        cache_eclsum=None,
         start_date=None,
         end_date=None,
         include_restart=True,
@@ -760,8 +761,28 @@ def load_smry(
             pd.DataFame: Summary vectors for the ensemble, or
             a dict of dataframes if stacked=False.
         """
+        if stacked is not None:
+            warnings.warn(
+                (
+                    "stacked option to load_smry() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+        else:
+            stacked = True
         if not stacked:
             raise NotImplementedError
+
+        if cache_eclsum is not None:
+            warnings.warn(
+                (
+                    "cache_eclsum option to load_smry() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+
         # Future: Multithread this!
         for realidx, realization in self.realizations.items():
             # We do not store the returned DataFrames here,
@@ -963,7 +984,7 @@ def get_smry_dates(
         normalize=True,
         start_date=None,
         end_date=None,
-        cache_eclsum=True,
+        cache_eclsum=None,
         include_restart=True,
     ):
         """Return list of datetimes for an ensemble according to frequency
@@ -996,6 +1017,17 @@ def get_smry_dates(
             list of datetimes. Empty list if no data found.
         """
 
+        if cache_eclsum is not None:
+            warnings.warn(
+                (
+                    "cache_eclsum option to get_smry_dates() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+        else:
+            cache_eclsum = True
+
         # Build list of list of eclsum dates
         eclsumsdates = []
         for _, realization in self.realizations.items():
@@ -1014,7 +1046,7 @@ def get_smry_stats(
         column_keys=None,
         time_index="monthly",
         quantiles=None,
-        cache_eclsum=True,
+        cache_eclsum=None,
         start_date=None,
         end_date=None,
     ):
@@ -1056,6 +1088,15 @@ def get_smry_stats(
             strings in the outer index are changed accordingly. If no
             data is found, return empty DataFrame.
         """
+        if cache_eclsum is not None:
+            warnings.warn(
+                (
+                    "cache_eclsum option to get_smry_stats() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+
         if quantiles is None:
             quantiles = [10, 90]
 
@@ -1105,6 +1146,13 @@ def get_wellnames(self, well_match=None):
             summary file or no matched well names.
 
         """
+        warnings.warn(
+            (
+                "ensemble.get_wellnames() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if isinstance(well_match, str):
             well_match = [well_match]
         result = set()
@@ -1135,7 +1183,13 @@ def get_groupnames(self, group_match=None):
             summary file or no matched well names.
 
         """
-
+        warnings.warn(
+            (
+                "ensemble.get_groupnames() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if isinstance(group_match, str):
             group_match = [group_match]
         result = set()
@@ -1323,7 +1377,7 @@ def get_smry(
         self,
         time_index=None,
         column_keys=None,
-        cache_eclsum=True,
+        cache_eclsum=None,
         start_date=None,
         end_date=None,
         include_restart=True,
@@ -1361,6 +1415,15 @@ def get_smry(
             REAL with integers is added to distinguish realizations. If
             no realizations, empty DataFrame is returned.
         """
+        if cache_eclsum is not None:
+            warnings.warn(
+                (
+                    "cache_eclsum option to get_smry() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+
         if isinstance(time_index, str):
             # Try interpreting as ISO-date:
             try:
@@ -1406,6 +1469,13 @@ def get_eclgrid(self, props, report=0, agg="mean", active_only=False):
             A dictionary. Index by grid attribute, and contains a list
             corresponding to a set of values for each grid cells.
         """
+        warnings.warn(
+            (
+                "ensemble.get_eclgrid() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         egrid_reals = [
             real for real in self.realizations.values() if real.get_grid() is not None
         ]
@@ -1432,6 +1502,13 @@ def global_active(self):
         :returns: An EclKw with, for each cell,
             the number of realizations where the cell is active.
         """
+        warnings.warn(
+            (
+                "ensemble.global_active() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if not self._global_active:
             self._global_active = EclKW(
                 "eactive", self.global_size, EclDataType.ECL_INT
@@ -1448,6 +1525,13 @@ def global_size(self):
         :returns: global size of the realizations in the Ensemble.  see
             :func:`fmu_postprocessing.modelling.Realization.global_size()`.
         """
+        warnings.warn(
+            (
+                "ensemble.global_size() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if not self.realizations:
             return 0
         if self._global_size is None:
@@ -1467,6 +1551,8 @@ def _get_grid_index(self, active=True):
         Returns: The grid of the ensemble, see
             :func:`fmu.ensemble.Realization.get_grid()`.
         """
+        # ensemble._get_grid_index() is deprecated and
+        # will be removed in fmu-ensemble v2.0.0
         if not self.realizations:
             return None
         return list(self.realizations.values())[0].get_grid_index(active=active)
@@ -1474,6 +1560,13 @@ def _get_grid_index(self, active=True):
     @property
     def init_keys(self):
         """Return all keys available in the Eclipse INIT file """
+        warnings.warn(
+            (
+                "ensemble.init_keys() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if not self.realizations:
             return None
         all_keys = set.union(
@@ -1488,6 +1581,13 @@ def init_keys(self):
     @property
     def unrst_keys(self):
         """Return keys availaible in the Eclipse UNRST file """
+        warnings.warn(
+            (
+                "ensemble.unrst_keys() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if not self.realizations:
             return None
         all_keys = set.union(
@@ -1501,6 +1601,13 @@ def unrst_keys(self):
 
     def get_unrst_report_dates(self):
         """Returns UNRST report step and the corresponding date """
+        warnings.warn(
+            (
+                "ensemble.get_unrst_report_dates() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if not self.realizations:
             return None
         all_report_dates = set.union(
@@ -1523,6 +1630,13 @@ def get_init(self, prop, agg):
             and corresponding values for given property as values.
         :raises ValueError: If prop is not found.
         """
+        warnings.warn(
+            (
+                "ensemble.get_init() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if agg == "mean":
             mean = self._keyword_mean(prop, self.global_active)
             return pd.Series(mean.numpy_copy(), name=prop)
@@ -1539,7 +1653,13 @@ def get_unrst(self, prop, report, agg):
             and corresponding values for given property as values.
         :raises ValueError: If prop is not in `TIME_DEPENDENT`.
         """
-
+        warnings.warn(
+            (
+                "ensemble.get_unrst() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if agg == "mean":
             mean = self._keyword_mean(prop, self.global_active, report=report)
             return pd.Series(mean.numpy_copy(), name=prop)
@@ -1558,6 +1678,8 @@ def _keyword_mean(self, prop, global_active, report=None):
             realizations where the cell is active.
         :param report: Report step for unrst keywords
         """
+        # ensemble._keyword_mean() is deprecated and
+        # will be removed in fmu-ensemble v2.0.0
         mean = EclKW(prop, len(global_active), EclDataType.ECL_FLOAT)
         if report:
             for _, realization in self.realizations.items():
@@ -1580,6 +1702,8 @@ def _keyword_std_dev(self, prop, global_active, mean, report=0):
             realizations where the cell is active.
         :param mean: Mean of keywords.
         """
+        # ensemble._keyword_std_dev() is deprecated and
+        # will be removed in fmu-ensemble v2.0.0
         std_dev = EclKW(prop, len(global_active), EclDataType.ECL_FLOAT)
         if report:
             for _, realization in self.realizations.items():
diff --git a/src/fmu/ensemble/ensembleset.py b/src/fmu/ensemble/ensembleset.py
index 83a0af33..e825b0d4 100644
--- a/src/fmu/ensemble/ensembleset.py
+++ b/src/fmu/ensemble/ensembleset.py
@@ -4,6 +4,7 @@
 import os
 import glob
 import logging
+import warnings
 
 import numpy as np
 import pandas as pd
@@ -571,7 +572,7 @@ def load_smry(
         self,
         time_index="raw",
         column_keys=None,
-        cache_eclsum=True,
+        cache_eclsum=None,
         start_date=None,
         end_date=None,
     ):
@@ -611,6 +612,15 @@ def load_smry(
             A DataFame of summary vectors for the ensembleset.
             The column 'ENSEMBLE' will denote each ensemble's name
         """
+        if cache_eclsum is not None:
+            warnings.warn(
+                (
+                    "cache_eclsum option to load_smry() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+
         # Future: Multithread this:
         for _, ensemble in self._ensembles.items():
             ensemble.load_smry(
@@ -630,7 +640,7 @@ def get_smry(
         self,
         time_index=None,
         column_keys=None,
-        cache_eclsum=False,
+        cache_eclsum=None,
         start_date=None,
         end_date=None,
     ):
@@ -664,6 +674,16 @@ def get_smry(
             ENSEMBLE will distinguish the different ensembles by their
             respective names.
         """
+
+        if cache_eclsum is not None:
+            warnings.warn(
+                (
+                    "cache_eclsum option to get_smry() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+
         smrylist = []
         for _, ensemble in self._ensembles.items():
             smry = ensemble.get_smry(
@@ -676,7 +696,7 @@ def get_smry(
         return pd.DataFrame()
 
     def get_smry_dates(
-        self, freq="monthly", cache_eclsum=True, start_date=None, end_date=None
+        self, freq="monthly", cache_eclsum=None, start_date=None, end_date=None
     ):
         """Return list of datetimes from an ensembleset
 
@@ -704,6 +724,15 @@ def get_smry_dates(
             list of datetime.date.
         """
 
+        if cache_eclsum is not None:
+            warnings.warn(
+                (
+                    "cache_eclsum option to get_smry_dates() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+
         rawdates = set()
         for _, ensemble in self._ensembles.items():
             rawdates = rawdates.union(
@@ -744,6 +773,11 @@ def get_wellnames(self, well_match=None):
             summary file or no matched well names.
 
         """
+        warnings.warn(
+            "ensembleset.get_wellnames() is deprecated and "
+            "will be removed in later versions.",
+            FutureWarning,
+        )
         result = set()
         for _, ensemble in self._ensembles.items():
             result = result.union(ensemble.get_wellnames(well_match))
diff --git a/src/fmu/ensemble/realization.py b/src/fmu/ensemble/realization.py
index 5762f6bd..561494da 100644
--- a/src/fmu/ensemble/realization.py
+++ b/src/fmu/ensemble/realization.py
@@ -15,6 +15,7 @@
 from datetime import datetime, date, time
 import dateutil
 import logging
+import warnings
 
 import yaml
 import numpy as np
@@ -949,7 +950,7 @@ def load_smry(
         self,
         time_index="raw",
         column_keys=None,
-        cache_eclsum=True,
+        cache_eclsum=None,
         start_date=None,
         end_date=None,
         include_restart=True,
@@ -1000,6 +1001,17 @@ def load_smry(
             DataFrame: with summary keys as columns and dates as indices.
                 Empty dataframe if no summary is available.
         """
+        if cache_eclsum is not None:
+            warnings.warn(
+                (
+                    "cache_eclsum option to load_smry() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+        else:
+            cache_eclsum = True
+
         if not self.get_eclsum(cache=cache_eclsum):
             # Return empty, but do not store the empty dataframe in self.data
             return pd.DataFrame()
@@ -1047,7 +1059,7 @@ def get_smry(
         self,
         time_index=None,
         column_keys=None,
-        cache_eclsum=True,
+        cache_eclsum=None,
         start_date=None,
         end_date=None,
         include_restart=True,
@@ -1079,6 +1091,18 @@ def get_smry(
         Returns empty dataframe if there is no summary file, or if the
         column_keys are not existing.
         """
+
+        if cache_eclsum is not None:
+            warnings.warn(
+                (
+                    "cache_eclsum option to get_smry() is deprecated and "
+                    "will be removed in fmu-ensemble v2.0.0"
+                ),
+                FutureWarning,
+            )
+        else:
+            cache_eclsum = True
+
         if not isinstance(column_keys, list):
             column_keys = [column_keys]
         if isinstance(time_index, str) and time_index == "raw":
@@ -1192,6 +1216,15 @@ def get_smryvalues(self, props_wildcard=None):
             a dataframe with values. Raw times from UNSMRY.
             Empty dataframe if no summary file data available
         """
+        warnings.warn(
+            (
+                "realization.get_smryvalues() is deprecated and "
+                "will be removed in fmu-ensemble v2.0.0. Process "
+                "columns from get_smry() instead."
+            ),
+            FutureWarning,
+        )
+
         if not self._eclsum:  # check if it is cached
             self.get_eclsum()
 
@@ -1410,6 +1443,13 @@ def get_init(self):
         """
         :returns: init file of the realization.
         """
+        warnings.warn(
+            (
+                "realization.get_init() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         init_file_row = self.files[self.files.FILETYPE == "INIT"]
         init_filename = None
         if len(init_file_row) == 1:
@@ -1433,6 +1473,13 @@ def get_unrst(self):
         """
         :returns: restart file of the realization.
         """
+        warnings.warn(
+            (
+                "realization.get_unrst() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         unrst_file_row = self.files[self.files.FILETYPE == "UNRST"]
         unrst_filename = None
         if len(unrst_file_row) == 1:
@@ -1455,6 +1502,13 @@ def get_grid_index(self, active_only):
         """
         Return the grid index in a pandas dataframe.
         """
+        warnings.warn(
+            (
+                "realization.get_grid_index() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         if self.get_grid():
             return self.get_grid().export_index(active_only=active_only)
         logger.warning("No GRID file in realization %s", self)
@@ -1462,6 +1516,13 @@ def get_grid_index(self, active_only):
     def get_grid_corners(self, grid_index):
         """Return a dataframe with the the x, y, z for the
         8 grid corners of corner point cells"""
+        warnings.warn(
+            (
+                "realization.get_grid_corners() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         if self.get_grid():
             corners = self.get_grid().export_corners(grid_index)
             columns = [
@@ -1498,6 +1559,13 @@ def get_grid_corners(self, grid_index):
     def get_grid_centre(self, grid_index):
         """Return the grid centre of corner-point-cells, x, y and z
         in distinct columns"""
+        warnings.warn(
+            (
+                "realization.get_grid_centre() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         if self.get_grid():
             grid_cell_centre = self.get_grid().export_position(grid_index)
             return pd.DataFrame(
@@ -1510,6 +1578,13 @@ def get_grid(self):
         """
         :returns: grid file of the realization.
         """
+        warnings.warn(
+            (
+                "realization.get_grid() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         grid_file_row = self.files[self.files.FILETYPE == "EGRID"]
         grid_filename = None
         if len(grid_file_row) == 1:
@@ -1531,6 +1606,13 @@ def global_size(self):
         """
         :returns: Number of cells in the realization.
         """
+        warnings.warn(
+            (
+                "realization.get_grid() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         if self.get_grid() is not None:
             return self.get_grid().get_global_size()
 
@@ -1541,6 +1623,13 @@ def actnum(self):
             Active cells are given value 1, while
             inactive cells have value 1.
         """
+        warnings.warn(
+            (
+                "realization.get_grid() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         if not self._actnum and self.get_init() is not None:
             self._actnum = self.get_init()["PORV"][0].create_actnum()
         return self._actnum
@@ -1550,6 +1639,13 @@ def report_dates(self):
         """
         :returns: List of DateTime.DateTime for which values are reported.
         """
+        warnings.warn(
+            (
+                "realization.get_grid() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         if self.get_unrst() is not None:
             return self.get_unrst().report_dates
 
@@ -1559,6 +1655,13 @@ def get_global_init_keyword(self, prop):
         :returns: The EclKw of given name. Length is global_size.
             non-active cells are given value 0.
         """
+        warnings.warn(
+            (
+                "realization.get_global_init_keyword() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         if self.get_init() is not None:
             return self.get_init()[prop][0].scatter_copy(self.actnum)
 
@@ -1568,5 +1671,12 @@ def get_global_unrst_keyword(self, prop, report):
         :returns: The EclKw of given name. Length is global_size.
             non-active cells are given value 0.
         """
+        warnings.warn(
+            (
+                "realization.get_global_unrst_keyword() is deprecated and "
+                "will be removed in later versions."
+            ),
+            FutureWarning,
+        )
         if self.get_unrst() is not None:
             return self.get_unrst()[prop][report].scatter_copy(self.actnum)
diff --git a/src/fmu/ensemble/virtualensemble.py b/src/fmu/ensemble/virtualensemble.py
index 994c93d2..35ba07a7 100644
--- a/src/fmu/ensemble/virtualensemble.py
+++ b/src/fmu/ensemble/virtualensemble.py
@@ -6,6 +6,7 @@
 import shutil
 import fnmatch
 import datetime
+import warnings
 import logging
 
 import yaml
@@ -468,6 +469,13 @@ def to_disk(
             symlinks (boolean): If includefiles is True, setting this to True
                 means that only symlinking will take place, not full copy.
         """
+        warnings.warn(
+            (
+                "to_disk() is considered deprecated and "
+                "might be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         if not HAVE_PYARROW:
             logger.warning(
                 (
@@ -641,6 +649,13 @@ def from_disk(self, filesystempath, fmt="parquet", lazy_load=False):
             lazy_load (bool): If True, loading of dataframes from disk
                 will be postponed until get_df() is actually called.
         """
+        warnings.warn(
+            (
+                "from_disk() is considered deprecated and "
+                "might be removed in fmu-ensemble v2.0.0"
+            ),
+            FutureWarning,
+        )
         start_time = datetime.datetime.now()
         if fmt not in ["csv", "parquet"]:
             raise ValueError("Unknown format for from_disk: %s" % fmt)
diff --git a/src/fmu/ensemble/virtualrealization.py b/src/fmu/ensemble/virtualrealization.py
index 096381ac..113d346b 100644
--- a/src/fmu/ensemble/virtualrealization.py
+++ b/src/fmu/ensemble/virtualrealization.py
@@ -2,6 +2,7 @@
 import os
 import fnmatch
 import shutil
+import warnings
 import logging
 
 import pandas as pd
@@ -78,6 +79,11 @@ def to_disk(self, filesystempath, delete=False):
             delete: boolean, if True, existing directory at the filesystempath
                 will be deleted before export.
         """
+        warnings.warn(
+            "to_disk() is considered deprecated and might be "
+            "removed in fmu-ensemble v2.0.0",
+            FutureWarning,
+        )
         if os.path.exists(filesystempath):
             if delete:
                 shutil.rmtree(filesystempath)
@@ -141,6 +147,11 @@ def load_disk(self, filesystempath):
             filesystempath: path to a directory that to_disk() has
                 written to (or a really careful user)
         """
+        warnings.warn(
+            "load_disk() is considered deprecated and might be "
+            "removed in fmu-ensemble v2.0.0",
+            FutureWarning,
+        )
         logger.info("Loading virtual realization from %s", filesystempath)
         for root, _, filenames in os.walk(filesystempath):
             for filename in filenames:
diff --git a/tests/test_ensemble.py b/tests/test_ensemble.py
index 12230a3f..3eb1930a 100644
--- a/tests/test_ensemble.py
+++ b/tests/test_ensemble.py
@@ -853,7 +853,8 @@ def test_eclsumcaching():
 
     # If we redo this operation, the same objects should all
     # be None afterwards:
-    ens.load_smry(cache_eclsum=None)
+    ens.load_smry(cache_eclsum=False)
+    # cache_eclsum==None is from v1.1.5 no longer equivalent to False
     assert not any([x._eclsum for (idx, x) in ens.realizations.items()])
 
     ens.get_smry()