diff --git a/classes/feeds.php b/classes/feeds.php
index bf165f93a..83e799cbc 100755
--- a/classes/feeds.php
+++ b/classes/feeds.php
@@ -1843,18 +1843,13 @@ class Feeds extends Handler_Protected {
 	}
 
 	static function _cat_of_feed($feed) {
-		$pdo = Db::pdo();
+		$feed = ORM::for_table('ttrss_feeds')->find_one($feed);
 
-	    $sth = $pdo->prepare("SELECT cat_id FROM ttrss_feeds
-				WHERE id = ?");
-	    $sth->execute([$feed]);
-
-		if ($row = $sth->fetch()) {
-			return $row["cat_id"];
+		if ($feed) {
+			return $feed->cat_id;
 		} else {
-			return false;
+			return null;
 		}
-
 	}
 
     private function _color_of($name) {
@@ -1905,6 +1900,15 @@ class Feeds extends Handler_Protected {
 		return preg_match("/<html|DOCTYPE html/i", substr($content, 0, 8192)) !== 0;
 	}
 
+	static function _remove_cat(int $id, int $owner_uid) {
+		$cat = ORM::for_table('ttrss_feed_categories')
+			->where('owner_uid', $owner_uid)
+			->find_one($id);
+
+		if ($cat)
+			$cat->delete();
+	}
+
 	static function _add_cat($feed_cat, $parent_cat_id = false, $order_id = 0) {
 
 		if (!$feed_cat) return false;
@@ -1942,42 +1946,31 @@ class Feeds extends Handler_Protected {
 		return false;
 	}
 
-	static function _get_access_key($feed_id, $is_cat, $owner_uid = false) {
-
+	static function _get_access_key($feed_id, bool $is_cat, int $owner_uid = 0) {
 		if (!$owner_uid) $owner_uid = $_SESSION["uid"];
 
-		$is_cat = bool_to_sql_bool($is_cat);
+		$key = ORM::for_table('ttrss_access_keys')
+			->where('owner_uid', $owner_uid)
+			->where('feed_id', $feed_id)
+			->where('is_cat', $is_cat)
+			->find_one();
 
-		$pdo = Db::pdo();
-
-		$sth = $pdo->prepare("SELECT access_key FROM ttrss_access_keys
-				WHERE feed_id = ? AND is_cat = ?
-				AND owner_uid = ?");
-		$sth->execute([$feed_id, $is_cat, $owner_uid]);
-
-		if ($row = $sth->fetch()) {
-			return $row["access_key"];
+		if ($key) {
+			return $key->access_key;
 		} else {
-			$key = uniqid_short();
+			$key = ORM::for_table('ttrss_access_keys')->create();
 
-			$sth = $pdo->prepare("INSERT INTO ttrss_access_keys
-					(access_key, feed_id, is_cat, owner_uid)
-					VALUES (?, ?, ?, ?)");
+			$key->owner_uid = $owner_uid;
+			$key->feed_id = $feed_id;
+			$key->is_cat = $is_cat;
+			$key->access_key = uniqid_short();
 
-			$sth->execute([$key, $feed_id, $is_cat, $owner_uid]);
-
-			return $key;
+			if ($key->save()) {
+				return $key->access_key;
+			}
 		}
 	}
 
-	/**
-	 * Purge a feed old posts.
-	 *
-	 * @param mixed $feed_id The id of the purged feed.
-	 * @param mixed $purge_interval Olderness of purged posts.
-	 * @access public
-	 * @return mixed
-	 */
 	static function _purge($feed_id, $purge_interval) {
 
 		if (!$purge_interval) $purge_interval = self::_get_purge_interval($feed_id);
@@ -2049,21 +2042,15 @@ class Feeds extends Handler_Protected {
 	}
 
 	private static function _get_purge_interval($feed_id) {
+		$feed = ORM::for_table('ttrss_feeds')->find_one($feed_id);
 
-		$pdo = Db::pdo();
+		if ($feed) {
 
-		$sth = $pdo->prepare("SELECT purge_interval, owner_uid FROM ttrss_feeds
-			WHERE id = ?");
-		$sth->execute([$feed_id]);
+			if ($feed->purge_interval != 0)
+				return $feed->purge_interval;
+			else
+				return get_pref(Prefs::PURGE_OLD_DAYS, $feed->owner_uid);
 
-		if ($row = $sth->fetch()) {
-			$purge_interval = $row["purge_interval"];
-			$owner_uid = $row["owner_uid"];
-
-			if ($purge_interval == 0)
-				$purge_interval = get_pref(Prefs::PURGE_OLD_DAYS, $owner_uid);
-
-			return $purge_interval;
 		} else {
 			return -1;
 		}
diff --git a/classes/pref/feeds.php b/classes/pref/feeds.php
index c7d4f1925..24bf68c47 100755
--- a/classes/pref/feeds.php
+++ b/classes/pref/feeds.php
@@ -22,14 +22,16 @@ class Pref_Feeds extends Handler_Protected {
 		return $rv;
 	}
 
-	function renamecat() {
-		$title = clean($_REQUEST['title']);
-		$id = clean($_REQUEST['id']);
+	function renameCat() {
+		$cat = ORM::for_table("ttrss_feed_categories")
+			->where("owner_uid", $_SESSION["uid"])
+			->find_one($_REQUEST['id']);
 
-		if ($title) {
-			$sth = $this->pdo->prepare("UPDATE ttrss_feed_categories SET
-				title = ? WHERE id = ? AND owner_uid = ?");
-			$sth->execute([$title, $id, $_SESSION['uid']]);
+		$title = clean($_REQUEST['title']);
+
+		if ($cat && $title) {
+			$cat->title = $title;
+			$cat->save();
 		}
 	}
 
@@ -513,11 +515,11 @@ class Pref_Feeds extends Handler_Protected {
 
 		$feed_id = (int)clean($_REQUEST["id"]);
 
-		$sth = $this->pdo->prepare("SELECT * FROM ttrss_feeds WHERE id = ? AND
-				owner_uid = ?");
-		$sth->execute([$feed_id, $_SESSION['uid']]);
+		$row = ORM::for_table('ttrss_feeds')
+			->where("owner_uid", $_SESSION["uid"])
+			->find_one($feed_id)->as_array();
 
-		if ($row = $sth->fetch(PDO::FETCH_ASSOC)) {
+		if ($row) {
 
 			ob_start();
 			PluginHost::getInstance()->run_hooks(PluginHost::HOOK_PREFS_EDIT_FEED, $feed_id);
@@ -720,48 +722,32 @@ class Pref_Feeds extends Handler_Protected {
 
 			$reset_basic_info = $orig_feed_url != $feed_url; */
 
-			$sth = $this->pdo->prepare("UPDATE ttrss_feeds SET
-				cat_id = :cat_id,
-				title = :title,
-				feed_url = :feed_url,
-				site_url = :site_url,
-				update_interval = :upd_intl,
-				purge_interval = :purge_intl,
-				auth_login = :auth_login,
-				auth_pass = :auth_pass,
-				auth_pass_encrypted = false,
-				private = :private,
-				cache_images = :cache_images,
-				hide_images = :hide_images,
-				include_in_digest = :include_in_digest,
-				always_display_enclosures = :always_display_enclosures,
-				mark_unread_on_update = :mark_unread_on_update,
-				feed_language = :feed_language
-			WHERE id = :id AND owner_uid = :uid");
+			$feed = ORM::for_table('ttrss_feeds')
+				->where('owner_uid', $_SESSION['uid'])
+				->find_one($feed_id);
 
-			$sth->execute([":title" => $feed_title,
-					":cat_id" => $cat_id ? $cat_id : null,
-					":feed_url" => $feed_url,
-					":site_url" => $site_url,
-					":upd_intl" => $upd_intl,
-					":purge_intl" => $purge_intl,
-					":auth_login" => $auth_login,
-					":auth_pass" => $auth_pass,
-					":private" => (int)$private,
-					":cache_images" => (int)$cache_images,
-					":hide_images" => (int)$hide_images,
-					":include_in_digest" => (int)$include_in_digest,
-					":always_display_enclosures" => (int)$always_display_enclosures,
-					":mark_unread_on_update" => (int)$mark_unread_on_update,
-					":feed_language" => $feed_language,
-					":id" => $feed_id,
-					":uid" => $_SESSION['uid']]);
+			if ($feed) {
 
-/*			if ($reset_basic_info) {
-				RSSUtils::set_basic_feed_info($feed_id);
-			} */
+				$feed->title = 							$feed_title;
+				$feed->cat_id = 							$cat_id ? $cat_id : null;
+				$feed->feed_url = 						$feed_url;
+				$feed->site_url = 						$site_url;
+				$feed->update_interval =				$upd_intl;
+				$feed->purge_interval =					$purge_intl;
+				$feed->auth_login = 						$auth_login;
+				$feed->auth_pass = 						$auth_pass;
+				$feed->private = 							(int)$private;
+				$feed->cache_images = 					(int)$cache_images;
+				$feed->hide_images = 					(int)$hide_images;
+				$feed->feed_language = 					$feed_language;
+				$feed->include_in_digest = 			(int)$include_in_digest;
+				$feed->always_display_enclosures =	(int)$always_display_enclosures;
+				$feed->mark_unread_on_update = 		(int)$mark_unread_on_update;
 
-			PluginHost::getInstance()->run_hooks(PluginHost::HOOK_PREFS_SAVE_FEED, $feed_id);
+				$feed->save();
+
+				PluginHost::getInstance()->run_hooks(PluginHost::HOOK_PREFS_SAVE_FEED, $feed_id);
+			}
 
 		} else {
 			$feed_data = array();
@@ -874,7 +860,7 @@ class Pref_Feeds extends Handler_Protected {
 	function removeCat() {
 		$ids = explode(",", clean($_REQUEST["ids"]));
 		foreach ($ids as $id) {
-			$this->remove_feed_category($id, $_SESSION["uid"]);
+			Feeds::_remove_cat((int)$id, $_SESSION["uid"]);
 		}
 	}
 
@@ -1188,12 +1174,6 @@ class Pref_Feeds extends Handler_Protected {
 		print json_encode($rv);
 	}
 
-	private function remove_feed_category($id, $owner_uid) {
-		$sth = $this->pdo->prepare("DELETE FROM ttrss_feed_categories
-			WHERE id = ? AND owner_uid = ?");
-		$sth->execute([$id, $owner_uid]);
-	}
-
 	static function remove_feed($id, $owner_uid) {
 
 		if (PluginHost::getInstance()->run_hooks_until(PluginHost::HOOK_UNSUBSCRIBE_FEED, true, $id, $owner_uid))
diff --git a/classes/rssutils.php b/classes/rssutils.php
index 73ddaa235..a50440e21 100755
--- a/classes/rssutils.php
+++ b/classes/rssutils.php
@@ -1713,9 +1713,9 @@ class RSSUtils {
 		$filters = array();
 
 		$feed_id = (int) $feed_id;
-		$cat_id = (int)Feeds::_cat_of_feed($feed_id);
+		$cat_id = Feeds::_cat_of_feed($feed_id);
 
-		if ($cat_id == 0)
+		if (empty($cat_id))
 			$null_cat_qpart = "cat_id IS NULL OR";
 		else
 			$null_cat_qpart = "";