tank not refilling after draining central heating system Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[kittyhiggs]

I'm freezing!
As my pipes were making loud tapping noises when the heating came, I was advised to drain the system. I logged on to this site and followed the instructions systematically - including tying up the ball cock in the tank in the loft. All seems to go well until the last 3 rads downstairs refused to empty. I decided to give up the ghost and refill the system. On returning to the loft I untied the ball cock, but on looking into the tank I could see it was dry (and had clearly been dry for some time). I followed all the insrtuctions for refilling but nothing seemed to happen- no gurgling or sounds of water refilling. The tank remained empty as did the radiators. I am now afraid to turn on the pump as I believe there is no water in the sysytem. I simply don't know what to do next. Do I fill the tank manually? I have a Worcester combi boiler if that makes any difference.
I am a complete novice and attemped this job in exasperation now I have made matters much worse. Although there's no tapping, there's freezing cold house instead.
Can somebody please help?

[marrtin]

Do not put the heating on until it is full of water. It could cause irreparable damage.

The reason the header tank will not fill is due to a stuck ball cock. This often happens in heating systems. Waggling it about is often sufficient to free it. If the float moves up and down freely, then it is probably totally seized and needs dismantling or replacing.

This valve could very well be the cause of your original problem.

You could as a last result refill the system manually but the faulty ball cock must be repaired asap.

<<< IGNORE THESE INSTRUCTIONS IF YOU HAVE A COMBI BOILER.>>>>

Sorry I did not notice you mentioned this fact. Combi's need to be filled using the filling loop near the boiler. The small heating header tank in the loft is unused, and should have been removed when the new boiler was installed.

[htg engineer]

Try to free the ball valve, when the arm rises is pushes a pin in which makes conatct with a rubber diaphragm/washer that closes the water supply.

The pin could be stuck, use a screwdriver to prise the pin away from the valve. If no luck try dismantling the ballvalve, and re-assembling or renew the ball valve.

You wont be able to use the heating until it is full of water - if you do you could cause more damage.

[haveimissedsomething]

Surely the tank is dry because the system has a combi boiler fitted as mentioned in the enquiry, hence no need for a tank in the loft ! :roll:

[htg engineer]

haveimissedsomething - maybe. but we can only work with the advice we're given, they tied the ball valve up to stop the system filling. We expect people that post on here to have a little bit of knowledge. Otherwise we cannot help, and the only option is to get a heating engineer out.

Never heard of or seen a tank fed combi ? I have one in my house

[yme]

Could the tank be bone dry and empty for a long time because it has been left defunct from previous old CH system and is not part of the new combi system?

[haveimissedsomething]

Maybe you have but there certainly combi heating systems that do not have a tank in the loft. It's very common and the state of this tank suggests that this system may be the same.

[kittyhiggs]

Doh!! I feel such a fool. It is indeed dry because I have a combi boiler and the tank is no longer a part of the system. I read the boiler manual and learned how o refill from there. In my defence (as a novice) I did complete step by step, the insructions on this web page. By the way the ticking has gone and I am warm. Thankyou all for taking the time to help.
Happy new year.

[htg engineer]

Glad you got it sorted.

I'll have to start reading posts properly again instead of skimming through. Missed the bit about you having a combi.

Sorry for the unhelpful posts.

[haveimissedsomething]

Glad you've got it sorted Kitty. O.K. I spotted the bit in your text about the combi boiler but am sure I'll be on here one day with a problem that others will help me with. Nice to know there are people around that will. Happy (warm) New Year to you and to htg engineer too !

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