Automatic Cistern Troubleshooting

6 January 2017

image of Automatic Cistern Troubleshooting


Cisterns are supplied as part of the package with Apinox Urinals and as an extra with WC pans other than the close coupled suite where the cistern is integral to the unit. 

  • Automatic Urinal Cisterns
  • Exposed Cistern for Urinals in Plastic or Stainless Steel (Model 131)
  • Concealed Cisterns for Urinals in Plastic only.

There are two common causes for a malfunctioning Urinal Cistern:

1. Incorrect Cistern Height 

The cistern has been mounted lower than its optimum mounting height with the result that the supplied downpipe has been pushed too far up into the syphon tail. This results in a continuously flushing cistern. 

The height range for a urinal cistern falls between 1800 and 2000mm measured from the underside of the cistern to the finished floor level. Reposition the cistern if possible or, if the mounting is within the permitted height range, shorten the down pipe to the desired length. The down pipe should be no more than 20mm inside the syphon tail. Do not cut the syphon tail pipe. 

2. Airlock in the Syphon

The other common cistern malfunction is caused by an airlock within the automatic syphon. This will result in the cistern continuously dribbling or flushing. This can be cured by opening the petcock fully and filling the cistern quickly to purge the air from the syphon. Alternatively a quick water fill using a bucket, or similar, will also work. 

  • Manual Lever or Push Button Air Operated WC Cisterns
  • Exposed Cistern for WC Pans in Plastic (Model 142) or Stainless Steel (Model 132)
  • Concealed Cistern for WC Pans in Plastic only (Model 142)

These cisterns very rarely malfunction. If you have a cistern that is not working correctly, please contact us for advice. Our technical team can be reached on 01452 721211 or by email at [email protected]

Urinal Fixings

Urinal fixings are normally packed inside a plastic bag which, in turn, is packed inside the cistern. This prevents loose parts rolling around and potentially scratching the urinal

The syphon, blanking buttons, petcock and washer are supplied as part of the cistern. 

The clips, "O" ring, cap nut, 22mm chrome plated coupler and 2" dome grated waste are supplied by Acorn Thorn as extras and are packed into the same bag. 


If you need any assistance or you are unsure of any of the above, please feel free to contact us


Our products are tested and certified to meet applicable standards. Not all products are covered by the same standards.
Products maunfactured outside the EU may have been tested to local standards which may meet or exceed EU standards.
Acorn Thorn Limited is registered in England & Wales no. 3094490. The registered address is as shown above. VAT registration no: (GB) 656 121 55
Ecommerce Web Site Design & Digital Marketing by Net Digital Bristol