Radiator cold after Draining and x800

[TryingHardDIY]

Hello,

I recently drain my CH system via a drain off situated outside the kitchen.

Before draining i cleared the header tank of muck,it was completely brown in color with at least a cm of sediment at the bottom, I will try post a pic soon. I then drained the system and opened the bleed valves to drain completely, letting it drain for around an hour.

I then put in 2l of x800 and filled the system again. Oddly the water looked clear when draining, strange considering we were told it had not been drained in years and the pump was making an awful noise and as mentioned above the tank was filthy.

Once the system had filled I then bled all the rads....tedious. The noise in the pump stopped within and hour often running the system...Brilliant.

Now this is where my question is, the rad in the kitchen right next to the drain off, which has worked the best out of all of them is only working on 1 side, about 1/4 of the rad, the rest is cold. I have read forums that suggest turning all other rads off to try flush the one affected. I tried this without luck.

When i bleed the radiator now it is pure black water coming out of the rad. Will draining the system again get rid of all the sludge that the x800 has dislodged? The water does seem a lot dirtier than before the x800. Is it worth draining and giving another dose of x800 again?

A plumber has recommended that due to the state of the system it might take upto 6 drains and x800 before it is fully functional. Which would still be cheaper than the £600 powerflush.

On a positive, the pump is silent and rads that did not work before are on full tilt. Is it coincidence the one nearest the drain off point is no longer warm?

Any suggesting would be apreciated.

Thanks in advance.

Untitled

• TryingHardDIY
• 22 Apr 2014
• 1

 

[Armo74]

Take the rad off and give it a good flush out with a garden hose.
Whilst its off open both valves into a bucket to make sure you have water flowing through and there's no blockage.

 

[ALCPlumbing]

You can beat a proper powerflush. Will make your heating more efficient and reduce your gas bill.
If you get a powerflush make sure they fit a filter after such a Magnaclean.

 

[TryingHardDIY]

Take the rad off and give it a good flush out with a garden hose.
Whilst its off open both valves into a bucket to make sure you have water flowing through and there's no blockage.

Thanks Armo74, Is it worth trying to drain it off through drain off valve first? I'm reluctant to take the rads off as they are pretty old and not sure how good the seal will be when i try put them in again.

I will be draining the whole system to flush out the x800 and then refilling with x100. If i have to i will take off the rad then, less mess, etc.. however i wont be able to test the flow as you suggest. How shall I test the flow to this rad if the system is drained?

Thanks again.

 

[TryingHardDIY]

You can beat a proper powerflush. Will make your heating more efficient and reduce your gas bill.
If you get a powerflush make sure they fit a filter after such a Magnaclean.

Thanks, but at 600 quid its not an option right now unfortunately. We have just had a new pump fitted last week so it should get the x800 flowing through the system sufficiently.

 

[Armo74]

You won't clear it without taking it off really.
Try a magnet around the exposed pipework to see if you have a blockage.
You shouldn't really be leaving the X800 in for a long time either.

 

[TryingHardDIY]

You won't clear it without taking it off really.
Try a magnet around the exposed pipework to see if you have a blockage.
You shouldn't really be leaving the X800 in for a long time either.

Thanks again Armo74, one last question...When re filling a drained system is there a correct order in which i should be bleeding the rads to avoid air locks? I.e. top floor first then bottom floor? or does it not matter?

Apologies for being a bit thick but what does the magnet do to tell you there is a block?

Thanks

 

[Armo74]

The build up of sediment is called magnetite,basically rust from the inside of the rads which is magnetic.
If there is a blockage then the magnet should be drawn to the copper pipe indicating a possible blockage.
When bleeding the system start with the downstairs rads first then the upstairs and any other vents you may have in the airing cupboard including the pump.