Hi, I contacted this forum a few months ago about problems with some radiators being cold (mostly downstairs) and it was suggested that sludge was blocking these rads. From the good advice i got, I used a litre of sentinel X400 in the system for a month, flushed it out and refilled. I also took off 3 easily accessible downstairs rads and hosed them through with mains water outside. After bleeding the rads I still have most of the downstairs rads cold or slightly warm ( including the ones flushed out). Upstairs ok. The bathroom rad upstairs at the end of the run is very hot, as is the hot water tank, also at the end of the run. The first rads nearest the boiler are hot (Both upstairs and down stairs)
The systems uses 28mm pipe from an Oil boiler with a gauge showing the water temperature at 70C. This pipework runs from the pump near the boiler to the first floor, with 15mm pipework feeding these upstairs rads and 15mm pipes looping down to each ground floor rads. I've even changed the pump (Grundos 15-60) to no avail. Most rads have TRV's and I've tried turning all upstairs off to try and force water tho downstairs rad with no success either. The return 28mm pipe is warm so presumably water is circulating and not blocked, so why doesn't the downstairs rads get equally hot ?/any ideas out there ?/
The systems uses 28mm pipe from an Oil boiler with a gauge showing the water temperature at 70C. This pipework runs from the pump near the boiler to the first floor, with 15mm pipework feeding these upstairs rads and 15mm pipes looping down to each ground floor rads. I've even changed the pump (Grundos 15-60) to no avail. Most rads have TRV's and I've tried turning all upstairs off to try and force water tho downstairs rad with no success either. The return 28mm pipe is warm so presumably water is circulating and not blocked, so why doesn't the downstairs rads get equally hot ?/any ideas out there ?/