diff --git a/cylc/flow/scripts/install.py b/cylc/flow/scripts/install.py
index bdf339fcc38..4bce90fabb2 100755
--- a/cylc/flow/scripts/install.py
+++ b/cylc/flow/scripts/install.py
@@ -89,11 +89,16 @@
 from cylc.flow.scripts.scan import (
     get_pipe,
     _format_plain,
+    FLOW_STATE_SYMBOLS,
+    FLOW_STATE_CMAP
 )
 from cylc.flow import iter_entry_points
 from cylc.flow.exceptions import PluginError, InputError
 from cylc.flow.loggingutil import CylcLogFormatter
-from cylc.flow.option_parsers import CylcOptionParser as COP
+from cylc.flow.option_parsers import (
+    CylcOptionParser as COP,
+    Options
+)
 from cylc.flow.pathutil import EXPLICIT_RELATIVE_PATH_REGEX, expand_path
 from cylc.flow.workflow_files import (
     install_workflow, search_install_source_dirs, parse_cli_sym_dirs
@@ -167,7 +172,7 @@ def get_source_location(path: Optional[str]) -> Path:
     """
     if path is None:
         return Path.cwd()
-    path = path.strip()
+    path = str(path).strip()
     expanded_path = Path(expand_path(path))
     if expanded_path.is_absolute():
         return expanded_path
@@ -182,33 +187,68 @@ async def scan(wf_name: str) -> None:
         'name': [f'{wf_name}/*'],
         'states': {'running', 'paused', 'stopping'},
         'source': False,
-        'ping': False,
+        'ping': True,  # get status of scanned workflows
     })
     active = [
         item async for item in get_pipe(opts, None, scan_dir=None)
     ]
     if active:
+        n = len(active)
+        grammar = (
+            ["s", "are", "them"]
+            if n > 1 else
+            ["", "is", "it"]
+        )
         print(
             CylcLogFormatter.COLORS['WARNING'].format(
-                f'Instance(s) of "{wf_name}" are already active:'
+                f'WARNING: {n} run%s of "{wf_name}"'
+                ' %s already active:' % tuple(grammar[:2])
             )
         )
         for item in active:
+            status = item['status']
+            tag = FLOW_STATE_CMAP[status]
+            symbol = f"<{tag}>{FLOW_STATE_SYMBOLS[status]}</{tag}>"
             cprint(
-                _format_plain(item, opts)
+                " ", symbol, _format_plain(item, opts)
             )
+        pattern = (
+            f"'{wf_name}/*'"
+            if n > 1 else
+            f"{item['name']}"
+        )
+        print(
+            f'You can stop %s with "cylc stop [options] {pattern}".\n'
+            'See "cylc stop --help" for options.' % grammar[-1]
+        )
+
+
+InstallOptions = Options(get_option_parser())
 
 
 @cli_function(get_option_parser)
-def main(parser, opts, reg=None):
-    wf_name = install(parser, opts, reg)
+def main(
+    _parser: COP,
+    opts: 'Values',
+    reg: Optional[str] = None
+) -> None:
+    """CLI wrapper."""
+    install_cli(opts, reg)
+
+
+def install_cli(
+    opts: 'Values',
+    reg: Optional[str] = None
+) -> None:
+    """Install workflow and scan for already-running instances."""
+    wf_name = install(opts, reg)
     asyncio.run(
         scan(wf_name)
     )
 
 
 def install(
-    parser: COP, opts: 'Values', reg: Optional[str] = None
+    opts: 'Values', reg: Optional[str] = None
 ) -> str:
     if opts.no_run_name and opts.run_name:
         raise InputError(
diff --git a/tests/integration/test_install.py b/tests/integration/test_install.py
new file mode 100644
index 00000000000..4c9023347e0
--- /dev/null
+++ b/tests/integration/test_install.py
@@ -0,0 +1,84 @@
+# THIS FILE IS PART OF THE CYLC WORKFLOW ENGINE.
+# Copyright (C) NIWA & British Crown (Met Office) & Contributors.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Test cylc install."""
+
+from pathlib import Path
+from shutil import rmtree
+from tempfile import TemporaryDirectory
+
+import pytest
+
+from .test_scan import init_flows
+
+from cylc.flow.workflow_files import WorkflowFiles
+from cylc.flow.scripts.install import (
+    InstallOptions,
+    install_cli
+)
+
+
+SRV_DIR = Path(WorkflowFiles.Service.DIRNAME)
+CONTACT = Path(WorkflowFiles.Service.CONTACT)
+RUN_N = Path(WorkflowFiles.RUN_N)
+INSTALL = Path(WorkflowFiles.Install.DIRNAME)
+
+
+@pytest.fixture()
+def src_run_dirs(mock_glbl_cfg, monkeypatch):
+    """Create some workflow source and run dirs for testing.
+
+    Source dirs:
+      <tmp-src>/w1
+      <tmp-src>/w2
+
+    Run dir:
+      <tmp-run>/w1/run1
+
+    """
+    tmp_src_path = Path(TemporaryDirectory().name)
+    tmp_run_path = Path(TemporaryDirectory().name)
+    tmp_src_path.mkdir()
+    tmp_run_path.mkdir()
+
+    init_flows(
+        tmp_run_path=tmp_run_path,
+        running=('w1/run1',),
+        tmp_src_path=tmp_src_path,
+        src=('w1', 'w2')
+    )
+    mock_glbl_cfg(
+        'cylc.flow.workflow_files.glbl_cfg',
+        f'''
+            [install]
+                source dirs = {tmp_src_path}
+        '''
+    )
+    monkeypatch.setattr('cylc.flow.pathutil._CYLC_RUN_DIR', tmp_run_path)
+
+    yield tmp_src_path, tmp_run_path
+    rmtree(tmp_src_path)
+    rmtree(tmp_run_path)
+
+
+def test_install_scan(src_run_dirs, capsys):
+    """At install, any running intances should be reported."""
+
+    install_cli(opts=InstallOptions(), reg='w1')
+    assert '1 run of "w1" is already active:' in capsys.readouterr().out
+
+    install_cli(opts=InstallOptions(), reg='w2')
+    assert '1 run of "w2" is already active:' not in capsys.readouterr().out
diff --git a/tests/integration/test_scan.py b/tests/integration/test_scan.py
index 94edbfc9b29..6cb405cea69 100644
--- a/tests/integration/test_scan.py
+++ b/tests/integration/test_scan.py
@@ -42,17 +42,20 @@
 INSTALL = Path(WorkflowFiles.Install.DIRNAME)
 
 
-def init_flows(tmp_path, running=None, registered=None, un_registered=None):
+def init_flows(tmp_run_path=None, running=None, registered=None,
+               un_registered=None, tmp_src_path=None, src=None):
     """Create some dummy workflows for scan to discover.
 
     Assume "run1, run2, ..., runN" structure if flow name constains "run".
+    Optionally create workflow source dirs in a give location too.
+
     """
     def make_registered(name, running=False):
-        run_d = Path(tmp_path, name)
+        run_d = Path(tmp_run_path, name)
         run_d.mkdir(parents=True, exist_ok=True)
         (run_d / "flow.cylc").touch()
         if "run" in name:
-            root = Path(tmp_path, name).parent
+            root = Path(tmp_run_path, name).parent
             with suppress(FileExistsError):
                 (root / "runN").symlink_to(run_d, target_is_directory=True)
         else:
@@ -63,12 +66,19 @@ def make_registered(name, running=False):
         if running:
             (srv_d / CONTACT).touch()
 
+    def make_src(name):
+        src_d = Path(tmp_src_path, name)
+        src_d.mkdir(parents=True, exist_ok=True)
+        (src_d / "flow.cylc").touch()
+
     for name in (running or []):
         make_registered(name, running=True)
     for name in (registered or []):
         make_registered(name)
     for name in (un_registered or []):
-        Path(tmp_path, name).mkdir(parents=True, exist_ok=True)
+        Path(tmp_run_path, name).mkdir(parents=True, exist_ok=True)
+    for name in (src or []):
+        make_src(name)
 
 
 @pytest.fixture(scope='session')
@@ -157,14 +167,14 @@ def source_dirs(mock_glbl_cfg):
     src1 = src / '1'
     src1.mkdir()
     init_flows(
-        src1,
-        registered=('a', 'b/c')
+        tmp_src_path=src1,
+        src=('a', 'b/c')
     )
     src2 = src / '2'
     src2.mkdir()
     init_flows(
-        src2,
-        registered=('d', 'e/f')
+        tmp_src_path=src2,
+        src=('d', 'e/f')
     )
     mock_glbl_cfg(
         'cylc.flow.scripts.scan.glbl_cfg',