diff --git a/electrum/channel_db.py b/electrum/channel_db.py
index 6fe7c0076..fef988454 100644
--- a/electrum/channel_db.py
+++ b/electrum/channel_db.py
@@ -382,7 +382,8 @@ class ChannelDB(SqlDB):
         c.execute("""REPLACE INTO policy (key, cltv_expiry_delta, htlc_minimum_msat, htlc_maximum_msat, fee_base_msat, fee_proportional_millionths, channel_flags, timestamp) VALUES (?,?,?,?,?,?, ?, ?)""", list(policy))
 
     @sql
-    def delete_policy(self, short_channel_id, node_id):
+    def delete_policy(self, node_id, short_channel_id):
+        key = short_channel_id + node_id
         c = self.conn.cursor()
         c.execute("""DELETE FROM policy WHERE key=?""", (key,))
 
@@ -391,6 +392,11 @@ class ChannelDB(SqlDB):
         c = self.conn.cursor()
         c.execute("REPLACE INTO channel_info (short_channel_id, node1_id, node2_id, capacity_sat) VALUES (?,?,?,?)", list(channel_info))
 
+    @sql
+    def delete_channel(self, short_channel_id):
+        c = self.conn.cursor()
+        c.execute("""DELETE FROM channel_info WHERE short_channel_id=?""", (short_channel_id,))
+
     @sql
     def save_node(self, node_info):
         c = self.conn.cursor()
@@ -467,6 +473,7 @@ class ChannelDB(SqlDB):
         l = self.get_old_policies(delta)
         for k in l:
             self._policies.pop(k)
+            self.delete_policy(*k)
         if l:
             self.logger.info(f'Deleting {len(l)} old policies')
 
@@ -476,8 +483,9 @@ class ChannelDB(SqlDB):
 
     def prune_orphaned_channels(self):
         l = self.get_orphaned_channels()
-        for k in l:
-            self.remove_channel(k)
+        for short_channel_id in l:
+            self.remove_channel(short_channel_id)
+            self.delete_channel(short_channel_id)
         self.update_counts()
         if l:
             self.logger.info(f'Deleting {len(l)} orphaned channels')
diff --git a/electrum/lnworker.py b/electrum/lnworker.py
index 88359854d..3626579c4 100644
--- a/electrum/lnworker.py
+++ b/electrum/lnworker.py
@@ -109,8 +109,6 @@ class LNWorker(Logger):
 
     @log_exceptions
     async def main_loop(self):
-        # fixme: only lngossip should do that
-        await self.channel_db.load_data()
         while True:
             await asyncio.sleep(1)
             now = time.time()
@@ -265,11 +263,13 @@ class LNGossip(LNWorker):
         self.network.trigger_callback('ln_status', num_peers, num_nodes, known, unknown)
 
     async def maintain_db(self):
-        self.channel_db.prune_orphaned_channels()
+        await self.channel_db.load_data()
         while True:
-            self.channel_db.prune_old_policies(self.max_age)
+            if len(self.unknown_ids) == 0:
+                self.channel_db.prune_old_policies(self.max_age)
+                self.channel_db.prune_orphaned_channels()
             self.refresh_gui()
-            await asyncio.sleep(5)
+            await asyncio.sleep(120)
 
     async def add_new_ids(self, ids):
         known = self.channel_db.get_channel_ids()
@@ -277,7 +277,7 @@ class LNGossip(LNWorker):
         self.unknown_ids.update(new)
 
     def get_ids_to_query(self):
-        N = 100
+        N = 500
         l = list(self.unknown_ids)
         self.unknown_ids = set(l[N:])
         return l[0:N]