rads

MANDATE

"removes any air lock in pipe work and flushes out sludge from pipe work. This leaves only the bleeding of the radiators."

Where do I find this air lock pipe? and how to I proceed.

Regards

Air locks in pipework is found where pipes go 'up' along then 'down' in the form of an inverted 'U' and because water enters this section of pipe (on refilling the system) from both ends trapping the air. The air is compressible making it difficult or impossible for the pump to circulate the water.To remove this air it is necessary to bleed it off if there is a bleed valve at the highest point, if not it is necessary to remove the resistance and allow the pump to push the water along without restriction and the way to achieve this is by removing the radiator and fitting a hose to the valve.
With the pump running the valve can be opened and two/three bucketful of water/air can be run off.
Repeat the action for the second valve.
I have used a clear hose connected across both valves which proved there was no flow and after running water off, it proved there was flow and the water flowing contained air which accumalated in the next radiator.

cheers mandate

I took off the flow valve to my rad opened it over a bucket with the pump running and nothing comes out no air no water????

very strange????

MANDATE said:

Air locks in pipework is found where pipes go 'up' along then 'down' in the form of an inverted 'U' and because water enters this section of pipe (on refilling the system) from both ends trapping the air. =

Click to expand...

I still don't understand this, i can't find any thing as described above.

Could this be under the floor board?

Thanks

Miah,
You're not looking for a specially made pipe, what I'm saying is the layout of some pipe work is such that an inverted 'U' is formed and when a system has been drained and is being refilled air can get trapped because it can't escape even when the pump is running. This is because the air is compressible and the pump is not powerful enough to deal with it because there is too much resistance to flow. Pockets of air in radiators are catered for by bleed valves and bleed valves can also be incorporated in a system if a air pocket/lock is likely. Most systems avoid having the inverted 'U' and those that don't rely on the pump to push any air to the radiators where in can be bled off.
Brakes on a car with a hydraulic system have a similar problem, if air gets in, the brakes become ineffective because the full pressure can't be applied.
The pump on a central heating system should be able to move the water around the pipe work without any great resistance and if it does not it is due to either.
pump not running
pump running in a air pocket and needs bleeding
sludge in pipe work preventing the water to flow
air pocket in pipe work preventing the water to flow
mid position valve (if fitted)not functioning

An air pocket in a radiator should not stop the flow of water around the pipe work supplying the radiators.
MW,
If there is no air or water coming from a radiator valve which is known to be open then I would suspect sludge causing a blockage but I would verify the pump is running and has been bled.

Thank you for your reply,

All your radiators are connected in parallel, okay, so turn off all the ones which have water obviously flowing through them. This will force flow through the cold rad(s), hopefully pushing the air lock out of the pipe.

If it was a sludge problem I 'd say you'd have noticed a fair bit when you flushed the rad.

ChrisR said:

turn off all the ones which have water obviously flowing through them.

This will force flow through the cold rad(s), hopefully pushing the air lock out of the pipe.
.

Click to expand...

Hi Chris,

Do you mean turn off all the RAD's vale which have problems ?

And, then swith on the boiler? -

This will force flow through the cold rad(s), hopefully pushing the air lock out of the pipe.

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