I can't bleed my radiators?

Question

The radiators at the top of my house refuse to bleed. They are cold at the top and warm (not hot) at the bottom. When I bleed them air comes out at the start but quickly fizzes out, then nothing no water, no more air, nothing. After this they gurgle for a bit and thats all????
The radiators down stairs are fine, and its fed from a combi boiler.
Any Ideas????
Thanks

Answer 1

Keep going untill a few drops of water come out.

Answer 2

Check the water pressure on your boiler, it shoud be about one or one and a half bar. If the pressure is okay and the rads are still not right, then the problem is that your boiler pump is not pumping high enough. or is broke. To test your pump, switch boiler on and put a screwdriver blade against the pump and your ear on the other end. If you don't hear the pump working, then that is your problem. As for venting rads with a Combi, you must switch the boiler off and wait 10 minutes then vent air from the rad, and check the waater pressure before you do the next rad. it is important to use this method because Combis have a low water content and if you vent air out then it has to be replaced by water straight away.To use any other method of bleeding will only result in more air getting into the system.

Answer 3

If the system operates using a SEPARATE Header tank, check that this is full with water. If it is not full you may need to turn ON the water supply to the ball valve. If the header tank is full check that the feeder pipe at the base (feeding water to the system) is not blocked, if it is clear it.

Now try to bleed your top level rads.

If your system works on a sealed pressure system with a pressure 'blister' (usually seen as a red small cylinder near the boiler and pump) your system may have become unpressurised, (eg via a leak somewhere). Unless you are technical in this case you should contact a good plumber.

Answer 4

I'm not a plumber or anything, but it sound like the water level in your radiator system is low, so essentially there isn't enough water and therefore pressure in the system to fill the upstairs radiators.

Go up into your loft and check the little water tank has water in, usually the heating level tank is a small tank off the side of the main tank. Or it is in my house at least! :)

Answer 5

when filling the system turn the boiler off as the pump may be running causing an airlock.as you fill each radiator close one valve to incease the pressure elsewhere.check for any micro flow valves that may be in off position and check all radiator vales work.
is the system only a single pipe or flow and return system?
undo slightly the nut on the radiator side of the valve to see if water is present.
could also fail to fill by lack of water pressure.turn all taps/washing machines/dishwashers off when filling system and check stop tap is fully open.if you open your cold tap a bit and put
your thumb over flow and stop the water you have a lack of
preesure from your waterboard

Answer 6

get someone to keep topping the boiler up to 1 bar as you bleed the radiators. as long as there is a steady 1 bar of pressure maintained at the boiler the air will be expelled as you bleed each rad. also, make sure both isolating valves on each rad are fully open.

Answer 7

remember that the presure should be on the green on th dial 1/2 bar as you bleed the rads this will drop so you need to represurise the system again you do this by opening the tap on the flexible loop you may hve to do this after bleeding each rad

Answer 8

You seem to be doing it right,but it may take awhile,after all youre bleeding an entire system thru a 1/16th in. hole(if that).Keep going till you have a steady stream of water,holding a bucket under it.(i'm assumeing this is a hot water system.)

Answer 9

you have to start at the top of the house when bleeding radiators. Start again from the top then see what happens

Answer 10

Not sure how combi boiler system works but if you.ve got a pump with variable speed, switch it to highest speed.