Radiators cold at bottom

[foxywadey]

Hi, looking for some info on radiators. My central heating system has 6 radiators, 4 of which have individual thermostats located at the top of the radiator. These 4 rads only get hot at the top [about 6 or 7 inches max.] while the bottom remains stone cold. I read the other posts on cold rads advising that the system get flushed but its only 4 or 5 years old & the 2 rads which don't have individual thermostats are hot all over so I'm wondering if its maybe because the thermostat is at the top & if so, how difficult it would be to get them moved to the bottom?

Really grateful for any advice.

Thanx

 

[John506]

it may only b 4 or 5 years old but if there wasnt any chemicals put in, it will be very sludged up

 

[mickyg]

Poor flow through the radiator will also cause a cold arc at the bottom. Try turning off all the radiators except one of the bad ones and see if you can get some flow through it.

 

[Soggy_weetabix]

Silly question, but the other pipe doesnt come out of the top of the radiator aswell does it?

If not, remove them and flush.

David