No HW after drained system

[chriselevate]

I drained my radiators to do some pipe cutting and tied up the valve in the header tank to do it. I've put water back into the system but when I press the heating control for HW I get how pipes on the cupboard leading up into the loft but all pipes going into/away from the HW tank are cold.

Any ideas?

Thanks

 

[crashndie]

hi mate it sounds like you have a air lock on the cylinder coils, is there a vent on the pipe leading to the flow of coil? if so you will need to open it and bleed the air out

 

[chriselevate]

Thanks for this and the quick response! Really appreciate it!

Here is a photo of what I think you are reffering to:

There's a plastic screw on the top which I've taken off and nothing happens?

There's plenty of cold water running out of the tank by the way if that helps?

Thanks

 

[mysteryman]

That's an automatic air vent, which is probably stuck shut. In theory, they can be unscrewed and an automatic valve will close as you remove it for repair or replacement. However - be careful! If you unscrew it partially to let the air out, and then retighten it, that should do the job. Do this with the system turned off. You should lag those pipes.

 

[crashndie]

^^^^^^ like the man said ^^^^^^^ if your still getting problems after you have bled it, turn the hot water on and give it few mins then turn it off again and re bleed it theres prob a fair bit off air in the system with the cylinder being in the loft

 

[crashndie]

how do you mean running out the tank ? is the over flow running out side ? is the ball valve still filling up ?

 

[chriselevate]

Sorry I ment that when I open up HW taps there plenty of cold water coming out. Would this not suggest that tank is filling up and the auto bleed is working?

Thanks

 

[mysteryman]

No, this pipe is carrying central heating water, not domestic hot water. It heats the cylinder via a heat exchanger coil inside the cyl.

 

[crashndie]

oh with you now lol no there seperate feeds the little tank you tided up fills the central heating water thats in the pipe with the auto vent on it. the water out the tap is dif

 

[chriselevate]

What would you suggest for getting the HW working again,

Thanks

 

[crashndie]

have u tryed to open the auto air vent?

 

[chriselevate]

A pair of grips on it and open it up to see it air comes out?

Will I start getting water everywhere? Or will it be much like a radiator?

Is the HW basically getting heated in the boiler and then going into the tank via that valve. And if that's locked with air the water can't get in?

Thanks

 

[chriselevate]

Think I've sorted it. Took the plastic tip off and pushed inside but nothing happened. Took the valve off by hand and all the air came out. Unfortunate water seems to bubble out of the too which I guess should be stopped by the valve but won't.

I've bought a new auto bleed valve and fitted that. Not sure if the other would have sprung into life with a few taps and shakes though. £6 bought the new valve... guess it's not worth trying to get the old one working? Just chuck it?!

Thanks