Boiler is producing plenty hot water, heating was working saturday on timer when I came home heating wouldn't come back on (first time using heating on timer - just moved in, boiler about four years old). My brother (electrician) checked in case hall thermostat kicked boiler off but he said...
Bled my rads, dropped pressure to 0, so increased it (to 2!!!). Since that there was a drip under pump? Service engineer came out recharged expansion vessel, replaced o ring and drip stopped. However pressure drops every night from 0.6 to 0 (but still have hot water and rads fine). Any idea...