ive had some problems with a boiler ive been working on. the pressure kept dropping, i found that water was coming out of the pressure relief valve,there was no pressure in the expansion vessel, i changed the expansion vessel and pressure relief valve and the boiler seemed fine,after a week or so the customer called and said the pressure is up and down and shes had to refill the system again. there are no leaks on the system. i noticed when i changed vessel there was sludge in the hose, blocked basically, could this be the prob. any advice would be helpfull, thanks

robert, December 2007

check secondary heat exchanger the sealed CH system may be leaking into DHW. Hence no visible leaks. and irratic pressure readings.

bob.harding@yahoo.co.uk, December 2007

dont forget to add inhibitor to the system as this helps to disperse sludge solids that caused the hose and its connecting points to block in first place !

combiking, December 2007

cheers gas man, but i put a new hose form boiler to vessel

robert, December 2007

clean the hose out to the expansion vessel and where it connects into the boiler.

Paul the gas man, December 2007