please help. glow worm k.f.b.50 wall hung boiler.fitted 1992. open vented system,2 zone valves and bypass.started banging in boiler and over heat stat operating. put sludge remover in and ran for 1 week, drained, filled and drained system 3 times and flushed thru boiler from boiler drain tap also.final fill added inhibitor also. ran perfect for 3 - 4 days now banging in boiler and over heat stat tripping.thermometers on flow and return pipes within 600 mm of boiler show diff of 10 degrees. ran on c/h only for 3 days .
,fine then started again, running on c/h only flow temp was about 60 degrees when room stat was satisfied, boiler was banging and after 15 secs or so o/h cutout tripped.tured up room stat to refire boiler, boiler stat set to maximum, boiler stat satisfied at 81 degrees, pump was still running on via stat pump over run,no banging and o/h did not trip. any ideas? both zone valves are working fine, all radiators get hot etc.when c/h or hot water stat is satisfied should the boiler and pump instantly shut down and if so would you expect water at 60 degrees to heat up so quickly from boiler residual heat to trip o/hstat which trips at approx 95 degrees.i fitted the system for my inlaws in 1992 any help greatly appreciated.
,fine then started again, running on c/h only flow temp was about 60 degrees when room stat was satisfied, boiler was banging and after 15 secs or so o/h cutout tripped.tured up room stat to refire boiler, boiler stat set to maximum, boiler stat satisfied at 81 degrees, pump was still running on via stat pump over run,no banging and o/h did not trip. any ideas? both zone valves are working fine, all radiators get hot etc.when c/h or hot water stat is satisfied should the boiler and pump instantly shut down and if so would you expect water at 60 degrees to heat up so quickly from boiler residual heat to trip o/hstat which trips at approx 95 degrees.i fitted the system for my inlaws in 1992 any help greatly appreciated.
