Central Heating - Some Radiators Work Others Don't?

Question

I have 2 radiators on each floor, i have 3 floors an 1 on the ground and 1 on the middle floor does not work but the other 4 are fine, what can be done.

Answer 1

Possible faults:
(1) Radiator not turned on
(2) Stuck thermostatic valve
(3) Needs bleeding
(4) Insufficient water in central heating system
(5) Poor pump
(6) Sludge
(7) System needs balancing
(8) Air locks

(1) Firstly make sure that these radiators are on: ensure that the valves on each side of the radiator are turned fully anticlockwise - you may need to take off the plastic cover and use a wrench to do this if the valves are stiff.
(2) If you have thermostatic valves on the radiators then a very common problem is that the pin that opens and closes the valve gets stuck in the closed position - wait until your central heating system is warm then remove the plastic thermostat head and you'll see a small pin that sticks up out of the valve (by about 3mm), spray the pin with oil and using a wrench work the pin up and down a few times and then firmly hit the side of the valve with your wrench several times - repeat several times or until you feel the heat entering your radiator.
(3) Once you are sure that both valves are both turned on, try bleed ing the radiator at the small screw at the top of the radiator - keep the bleed screw open until water starts to run out and then tighten it back up (you'll need a bleed key - available from any DIY store). You should bleed the radiators with the central heating system switched off.
(4) If you find that no water comes out when bleeding then there's a problem with the amount of water in the system. There are 2 possible problems:
(a) If you have an 'open vented' system, with a header tank in the loft then you could have a problem with either it's ball-valve (will need replacing) or a blockage in it's outlet (call in a plumber).
(b) If you have a 'system boiler' then you will need to repressurise the boiler - see your boiler documentation.
(5) Assuming that the radiator bled ok and the radiator is still not warming then the pump may be wearing out and will need replacing (to test this try turning off 2 or 3 of the radiators that work and if the cold radiators start warming then replace the pump)
(6) The could be 'sludge' (black iron oxide) in the system and will need flushing - this problem only ususaly affects the lower radiators - for flushing you will need a plumber or buy a central heating cleaning chemical from a DIY store and follow it's instructions.
(7) Balancing - this involves turning down the hot radiators to allow more flow to the colder radiators - usually only an issue at larger properties or where the plumbing is poor.
(8) Air locks - close off all hot radiators and wait for the cold ones to warm, if it was an air lock and the radiators start to warm (may take a day or 2) then re-open the other radiators and all of them should then stay warm - this technique works with varying degrees of success.
Good-luck! Regards Darryl (Heating Engineer, Acorn Plumbing & Heating)

Answer 2

Central Heating Radiators Not Working

Answer 3

Could be air in your system, there should be a bleed valve on the top of each radiator...simply open it 1/4 turn (no more than 1/4 turn!) and bleed out the air. It could also be the zone valve. Does each radiator have it's own thermostat or does all radiators work off 1 thermostat? If all 3 operate off 1 thermostat then it's probably air in your system. If there is 3 thermostats then it may be a bad thermostat or a bad zone valve ( that's the valve usually by the boiler that operates off the thermostat). For each thermostat...there is a zone valve. Any more questions...email me...I'll check every 1/2 hour. good luck. Remember that all these lines are hot so be careful!

Answer 4

It is most generally that the water flow is clogged by calcium deposits. A water softener should be added to keep this from happening again. The water lines may need to be replaced or the radiators may be the only thing "clogged". If they are the culprit then you can remove them and run a calcium removing liquid through them. Sometimes vinegar is used but it would take a long time. I would suggest checking with a local plumbing company for the best solution that they suggest. Have a great Christmas with your family.
Eds

PS... The others may also be correct about air in the line, but it is not very likely unless you have had the radiators off and the water drained from them.

Answer 5

Central Heating Not Working

Answer 6

Check your valve line up, particularly if there were any recent repairs to the system or if someone was too warm during the summer and the 2nd floor was isolated. Check your pressure at the heater/boiler and vent the air out of the radiators. Also, your thermostat or zone valve could be at fault.

Answer 7

You may need to drain your system and flush out all the gunge. Re-fill and start again, bleeding each rad in turn. Keep topping up the pressure if it's a sealed system. You can add some stuff to keep it free - Plumb Centre or any plumbers mrechants will advise.

Answer 8

Hot water is obviously not flowing through that radiator. Try bleeding trapped air from that radiator.

Answer 9

What happens sometimes is that air builds up in the lines, find the part that lets you bleed the air out of the lines..
usually it is just a small screw, you put your heat up high, unscrew the screw and you will feel air coming out, as soon as the air is let out hot water should be coming out.. Once this happens tighten the screw and it should work fine !!

Answer 10

obvious question to ask is are they turned on? then they made need 'bleeding' to remove air from them. if there's air in them they can't fill up with hot water and therefore stay cold.
you can get a radiator key from any hardware shop. it's a standard fit with all for bleeding.