Radiators cold at bottom

[Mr-H]

I know that rads should be bled if they are hot at the bottom and cold at the top. What is the problem/solution please, if it is the other way around, cold at the bottom etc?

[The Builder]

Seem to have been getting a lot of this recently MrH
First thought is the rads need balancing. Maybe some are taking more than their fair share.
Also, possibility, pump speed too low to get the water around fast enough.
Also, possibility, sludge in bottom of rad.

[anneasquith]

i had this problem in my old house. oldish radiators. sludge.

[emeraldblue]

Suggest you read the post from yesterday on Home & Garden DIY.It should answer your question fully

[Mr-H]

many thanks folks

[Mr-H]

Is there any way that the sludge can be moved without a full bleed and refill of the system? Is a new system/radiator really the only answer?

[The Builder]

a single rad can easily be removed for flushing................... shut down both valves and disconnect the valves from the rad .................... turn rad upside down to stop dirty water going everywhere ............... it is a bit messy :o(

[bizzylizzy]

They might simply need bleeding. I'd try that first before you go down the emptying route.