I have a blocked drain in the kitchen: I tried to fix it disassembling the U shaped drain under the sink, but the problem was not there. Also, I tried to use caustic soda but it didn't work, so I need to look for professional help.

Also (less urgent), I see you are gas safe registered: would you be able to do a gas safety check? I bought the house 1 year ago, everything was ok, but I didn't do any check since then.

thanks, David