why does the bottom of one of my radiators gets warm and the top stays cold?

Answer 1

you should know the bleeding answer by now

but just in case you have not twigger it

if it is a new system, When new water is added to the central heating system, a certain amount of air also enters the system. The action of the impeller of the pump will also 'create' a certain amount of air.

The most common area of trapped air is in radiators. This is fairly easy to detect as the air will reduce the amount of heat radiated. With the central heating switched on, feel the top and then the bottom of the radiator - if the top is noticeably cooler than the bottom, there is a good likelihood that there is air in the radiator.

It's a good idea NOT to bleed radiators with the central heating pump ON - if you do, there's always a risk that air might be drawn into the system making your problems worse.

Note that bleeding a sealed system will reduce the pressure which will need to be adjusted afterwards - this is normally done by turning on the mains cold water feed to the system - if in doubt, consult a heating engineer.

most systems are open, and have an expansion tank at the top, which will re-fill as you bleed the system, adding more air to the system to bleed in a few days time.

over the summer, the water in your system lies idle, and corrodes away at the iron parts of your heating system, this produces 'sludge' in the system. Sludge is a 'mud' resulting from the reaction between the water and oxygen in your system and the steel in the radiators which can build up over a period of time and cause circulation and flow problems.

have fun, and dont forget to use a bit of cloth to stop the water, which will pee out over your walls when the air is finished rushing past the bleed screw, the trick is to do it slowly, open the bleed drain 1/2 a turn, and don't tighten it up to hard...

Answer 2

HI, it sounds like you have air in your radiator, there is a bleed screw on right top, be careful , there is a purpose key for the job, turn the screw a little bit and you will hear air escape,once you hear the air coming out stop turning the key, you will then feel the radiator getting hot all the way up to top, when all the air has come out water will bubble out this will indicate that the trapped air has come out. Close the screw firmly, then the job should be done, be careful the water coming out will be hot what I do is hold the key with a tea towel. I hope this will help, All the best, FRED

Answer 3

it's because the water in your radiator does not reach the top.
every system has a weakened radiator.
you will find you will have to keep a check on this one.
it's usually the bathroom radiator that is affected.

all you need to do is get a radiator bleed key for a d i y shop. they don't cost much. make sure you have a towel or something to catch any water that escapes but remember it may be hot water.

put the key over the screw type thing on the end of the radiator and turn it. you will hear the air coming out.
don't open it to far or you'll be covered in water when it begins to come out.

when your getting water (it will be a bit mucky) turn it back to shut the valve. keep your bleed key safe as you will need it again.

keep a check on your radiator and if it happens again repeat the process.

good luck. hope this helps and i hope this cures your problem. if not, you'll need a plumber but I'm sure it will x

Answer 4

if it is bleeding that is need you are lucky a a little key from a diy shop costs about 2 pounds. just find the hole at the end of the radiator and insert the key. twist and you will here hissing, when a little water comes out twist the key closed again.
use a cloth to stop water spilling on carpet.
if this doesn't fix it, there may be a build up of silt and sludge in the radiator and you will need special chemicals and a machinery to force it out of the pipes and radiators.
if the bleeding doesn't work, call a plumber

Answer 5

Radiator needs bleeding by the sounds of it. Can purchase a bleeding radiator key from diy stores or some hardware stores. Put key into end of radiator and twist. You will hear air coming out - keep open until tiny drop of water comes out then tighten up again.

Answer 6

Could be an air lock and the radiator needs bleeding to let the air out. Or, if it has got an independent thermostat, is that radiator switched on.

Answer 7

From the pipes at the bottom thats where all the warm water comes in so it starts to get warm at the bottom and then gradually gets to the top

Answer 8

because it needs 'bleeding' - a special tool fits on the side of the radiator that allows the built-up air to escape. However you will need to make sure that there is then enough pressure in your boiler system after doing this.

Answer 9

Sounds like you've got an air lock. Try 'bleeding' your radiator which should improve things.

Answer 10

Does your boiler stir up ? If particular, the pump could be defective. If no, you need to verify the timer. Is it programmed properly and set to the the superb option time. If particular, verify the mains power to the device (fuse and turn). If thats ok, the motorised valve could desire to be defective. there's a change interior the motorised valve which operates while the valve opens, and this feeds power to the boiler and pump. verify additionally the room thermostat and boiler thermostat settings.