Nightmare with one radiator

[howza18]

Morning,

I have read through these fourms and others till my Head is spinning and cant find an answer to my problem...

Here goes , Kitchen radiator freezing , just suddenly stopped last week,

So far i have :

1/ Taken it off and flushed it out with a hose , removing all the end caps till the water was clear.
2/ Done the " Bucket Test " Shut all the radiators off in the house , opened one of the dodgy radiator valves into a bucket and water came flowing out , did the same with the other end and that flowed well also, ran about half a bucket of water into the bucket from each end. Connected the radiator and filled it , the water coming out the pipes was hot as i had the heating on and it filled the radiator and for the period the heating was on it stayed hot. sadly when the heating went off and they rad cooled down it didnt heat up again when the heating came on.
all other radiators have been bled and work well.
3/ Checked water tank in loft and that is full and topping up the system well
4/ turned all rads in house off barr the dodgy one , whacked heating up and still didnt work.
5/ The rad does not have a TRV on it , not sure why as most of the others do. House is 9 years old and has the plastic pipes leading to the radiator.

I am at a loss as what to do next prior to getting a heating engineer in which i believe isnt cheap !! ( tight wad ).

All suggestions would be recieved with thanks.

Andy - Durham

 

[GrahamPearce]

Hi

A shot in the dark here, but there are two valves on a radiator, one of which can be thermostatic, and the other is adjustable in order to balance flow through the radiators, i.e. restrict flow.

Could it be that this second vale is either down tight or blocked?

It was just a thought.

 

[howza18]

Hello , thanks for the reply.

Both valves open and close well and water flows through each when not connected to the radiator .

I thought that may have been the problem also.

Thanks again
Andy

 

[howza18]

I have had a ponder ,

Could my "problem" be and airlock in the radiator ??


I saw a video how to get rid of an airlock using a hose and a half inch male thread fitting that goes into the bleed valve after the water pressure has been dissapated.

No idea where to get this half inch male fitting that fastens into the hose mind. had a look on the Plumb centes website , no joy.


So , does anyone think that is a good idea and is it a major job , it didnt look that complicated in the PLUMBERPARTS video on you tube.

Regards

Andy.

 

[MANDATE]

Can't be a air lock in the radiator. Air in a radiator rises to the top and bleeding it allows the air to escape. You know its ok when it's just water coming out.
One thing you could try: Close one of the radiator valves and bleed radiator. OK now close the open valve and open the closed valve and bleed again. There may be a blockage in either flow or return pipe and this will indicate which one.
Another idea I have used, is to obtain fittings to fit to valves in lieu of the radiator tails then connect them together with clear plastic tubing.
Fit this in place in lieu of the radiator.
When I did this I could see there was no flow through the clear pipe.
Obviously a restriction! Then like the bucket test I ran of a couple of bucketful of from both flow and return pipes until I could see flow through the clear pipe. Only then did I re fit the radiator.
I think you may have a 'air lock' in the pipework and perhaps not enough water run off to release it

 

[howza18]

Mandate ,

You are a gentleman.

I tried the Open one airlock and bleed and vice versa and it seems to have worked. The Radiator has turned on this morning and heated up allthough not as hot as the others so i will do it again to see if i can get a bit more air out.


Thanks very much again,

The kitchen is no longer like Ice Station Zebra, result...


Cheers Buddy

Andy

 

[howza18]

Spoke too Soon !!!!


It has packed in again. DOH..


But i think you are correct about he air lock in the pipe.


Any easy ways to remove this anyone ??

Cheers

Andy

 

[MANDATE]

The problem with air is that it's compressible and when in a pipe it would take for ever and a day to get rid of it by bleeding a radiator.
Apart from using the clear hose you could try.
closing the by pass valve if you have one or maybe draining some water off if you can from the radiator valve

 

[Andygasman2010]

What colour is the water you've been draining off? Are there small black flakes in it?

 

[weargas]

Something no-one seems to have asked yet but have you recently replaced the pump or diverter valve (if you have one) Is this radiator the furthest away from your airing cupboard?

 

[howza18]

Gentlemen,

Thank you very much for your replies,

Heres what i finaly did that seemed to work :

I connected a hose to the drain valve .

Shut both valves off

Bled the radiator till the water stopped flowing out the bleed nipple then shut the bleed valve.

Opened the drain off valve ( a square nut type thing ) no water coming out.

Opened the valve at one end into a bucket and it started to fill. Bubbles in the water. Ran off about a quarter of a bucket.

Shut that valve then opened the other end and did the same , air came out of this end also. ran off quarter of a bucket.

Disconnected hose after closing the nut, opened both valves , opened bleed nipple till water came out and let it run for 10 seconds. closed it then stuck the heating on and the radiator is scorchio.

I just hope that when it goes off it comes back on in the morning.

Thanks very much AGAIN..

Andy