Replacing/repairing Howson's Siphonic toilet unit?

The problem is probably caused by the blockage of the small tube, moulded in the toilet pan, which starts the siphonic action working. Limescale is most likely the culprit.
Physical removal is best solution - if you can get access. Alternatively you could try a chemical clean with a hydrochloric acid limescale remover. Some ingenuity may be needed to find the best way to get the cleaning agent to the right place. As the proprietary agents are quite dilute they need to be applied neat. I used a squeezy bottle (tomato ketchup) and some small diameter poly tube fed through a hole drilled in the top of the siphon tube in the close-coupled cistern. The hole must of course be plugged when finished.

ernie w
September 2008

Thanks for replying Matthew.
I have asked around and possibly have found a solution. When I have dismantled the offending part I will post a further update. Possibly in a weeks time. I will be taking pictures as I go so hopefully I will have a record of how to repair it.

John Bamber
January 2008

Hello John

Sorry I can't help but also have exactly the same problem with my old Howson toilet and I'm trying to find an old siphone that will work in it.

Good luck

Matthew Walmsley

Matthew Walmsley
January 2008