Home-Made Power Flush?

[cinman2003]

Please don't shoot me down in flames for my stupidity, but I was wondering if a home-made power flush might be a good idea or not, considering I'm skint just before Xmas and my heating is crap? I've tried lots of other work, and come to the opinion that power flush is required (see my previous thread for details). So, could hire for £80'odd or could I use the cold water pressure instead?

1. Bung the expansion pipe above the F&E tank.
2. Get ready to open the drain value, via hose pipe, to drain
3. Connect cold water tap, via separate hose pipe, to the feed pipe from the F&E tank (the one below the water level)
4. Close all rads with both valves on each
5. As I turn on the cold water tap, I also open the drain valve

Surely that'd use cold water pressure to "blast" through the pipes, hopefully dislodging the more stubborn crud? It might even dislodge any air pockets or traps? Then would lower cold tap pressure, close drain valve, turn off cold tap (in that order), add inhibitor to F&E tank, un-bung expansion pipe, and you're a good'un.

Is that complete tosh, or am I barking up the right tree for a "Dragon's Den" stylee cheapo-power-flush?

 

[MJN]

Impossible to say - like anything requiring cleaning the necessary level depends entirely on how dirty it is.

I've flushed out many a system using such a technique (sealed systems so it's been a lot easier, and uses the filling loop) however they've not been so bad as to require anything more.

Make sure you open up the valves fully on the radiator being flushed as you want to maximise the clearout without getting another blockage. You may also want to consider running a cleanser in the system for a while beforehand (i.e. a week or so).

Mathew

 

[joinerjohn]

I wouldn't have thought that turning the radiators off would flush anything out of the rads. The idea with a powerflush is to flush the whole system out, not just the pipework.
Have a look on Youtube for The Tomplum. He has a video about doing just what you suggest.

Might be an idea to take off each rad in turn and flush these individually though, then flush the pipework after.

Edit, here's a link to Tom's video.
http://www.youtube.com/user/TheTomplum#p/u/25/pYURwv4Ci2A


Have a look at his other video's too. The tip on multimeters is a classic.

 

[MJN]

I wouldn't have thought that turning the radiators off would flush anything out of the rads.

I was assuming he'd accidentally missed out the step whereby each radiator is opened in turn!

Mathew

 

[Tibbot]

The crud won't move unless it's chemically disolved, suspended in warm water, then flushed out.

 

[cinman2003]

Sorry guys, should've said I've already flushed the rads individually by removing them. I'm really after getting the pipework "cleaned out" if poss. Also forgot to mention the step to put the 3-port valve to "manual" first, as the h/w circuit seems fine.

 

[Tibbot]

Still won't work. Water passed through will choose the path of least resistance before it stops to collect crud. The more pressure behind it, the faster it exits the other side without collecting the crud.

 

[MJN]

What other side? If each leg is closed off such there's only one way route through then there's every chance he may shift it.

To the OP it may be worth you going back a few steps and determining if whatever problem you've got is down to what you think it is.

Mathew

 

[Tibbot]

The side that's being drained. Don't take my word for it, take any section of crudded pipe or a rad into the garden and try shifting it with cold water alone. The crud has to be shaken, stirred or dissolved.

 

[bengasman]

Cleaning a badly soiled system requires knowledge, if you don't have the knowledge, I'd advice against wild experiments.

Look in faq for basic answers.

 

[MJN]

The side that's being drained. Don't take my word for it, take any section of crudded pipe or a rad into the garden and try shifting it with cold water alone. The crud has to be shaken, stirred or dissolved.

That's what the pre-application of cleanser achieves - it helps dislodge the crud whilst the detergents provide suspension. Careful application of a rubber mallet can certainly help further.

I'm not claiming guaranteed results - not even a full all-expense powerflush can do - but I have had many a success with this technique. It is far from being a 'wild experiment'. It's all relative I suppose...

Mathew

 

[Tibbot]

You may have done, but the OP (to whom I was answering) has not mentioned using cleansers.

 

[iep]

I carried out exactly this procedure two weeks back on my vented system. In our case pumpover had introduced a load of air into the system and the subsequent corrosion left the water a horrible brown colour. I don't think it had got to the sludged up stage yet but wanted to do more than drain and refill.

I followed exaclty the procedure you mention (including opening each rad in turn to direct flow of water) but ran a can of x400 through the system for a week beforehand.

Flushed each rad in turn and then the whole system for a couple of hours until the water from the drain off ran totally clean.

Critically, this worked in my system because I was able to inject the mains water on the flow side and drain on the return side of the boiler so I was genuinley flushing the whole system out.

I also added another spur to the pipework so I could add a pressure gauge just after the mains water inlet point which let me know when I was exceeding 2 bar (which I arbitrarily decided would be my max value).

Total cost was about £60 including parts, one can of x400 and two of x100.

If you are careful, I reckon this is a winner.

ip

 

[joinerjohn]

I have heard of BG offering powerflushes at somewhere around the £600 -£700 mark, so there are definite savings to be made by DIY methods.
Mind you, BG will probably offer to sell you a new system shortly after their powerflush.