vokera 80 excell?

Three port valve?. The bits for servicing the valve are in the maintenance kit (an o ring gasket, a push rod o ring seal holder, a bobbin and a washer) that you find advertised on ebay for a tenner. (for example Excell/eclipse service kit ebay #300178231924). Download the pdf manual from www.vokera.co.uk. Or it could be that the fulcrum arm isn't moving far enough because the domestic hot water diaphragm (also in service kit) is on its way out.

c
December 2007