plumbing. my bathroom tap suddenly is down to a trickle but is ok when cistern flushing.?

This success is limited to when I have theon/off water screw just on. When full on I get just the trickle. All other taps working normally. The system is a four month old combi (ariston) How can I check water pressures or am I wide of the mark?

Public Comments

1. you have air in the line
2. Most taps have a screw on filter at the end, you should check to see if the filter is clogged before doing anything costly.
3. change tap rubber seals