worcester Bosch combi
8 rads 4 up 4 down
system feeds 1 rad downstairs then 2 rads upstairs then 1 downstairs then 2 upstairs then long loop downstairs feeds 2 then return back upstairs and back down to boiler.
All radiators except last 2 work fine get hot quickly last two dead slow. Turned all others down to star on thermostat except those 2 and 1 other downstairs and they worked OK. Turned on one other rad at a time until all but one on and system working fine. Turned it off cooled down - turned on again and the last two not heating well again. Tried balancing system but some rads feeding thro non thermostatic valve end.
Had plumber in previously- hit pump or thereabouts gently with hammer and system worked. Switched off and then started again but problem still there.
Any suggestions??????Polite ones please.
8 rads 4 up 4 down
system feeds 1 rad downstairs then 2 rads upstairs then 1 downstairs then 2 upstairs then long loop downstairs feeds 2 then return back upstairs and back down to boiler.
All radiators except last 2 work fine get hot quickly last two dead slow. Turned all others down to star on thermostat except those 2 and 1 other downstairs and they worked OK. Turned on one other rad at a time until all but one on and system working fine. Turned it off cooled down - turned on again and the last two not heating well again. Tried balancing system but some rads feeding thro non thermostatic valve end.
Had plumber in previously- hit pump or thereabouts gently with hammer and system worked. Switched off and then started again but problem still there.
Any suggestions??????Polite ones please.