I have a bosch combi boiler, but the water pressure keeps going up even though the filling loop is disconnected

Michael wickett, April 2005

ITS ONE OF 2 THINGS THE DHW HEAT EXCANGER OR ITS YOUR PRESSURE VESSEL,CHECK 4 WATER AT THE VESSEL AT THE BACK,IF NON U COULD RECHARGE IT WITH A BIKE/CAR TIRE PUMP......BUT U MUST ALSO HAVE THE BLOW OFF OPEN AT THE SAME TIME AS PUMPING......IF THE GUAGE IS CONTINUALY RISING WHEN THE HEATING SYSTEM IS FULL ITS YOUR HEAT EXCHANGER.GOOD LUCK!

PAUL THE PLUMBER, March 2008

if you have a plated heat exchanger it could be letting by

d.., April 2005