money saving DIY system flush?

[brentwood]

Here's the result. Bear in mind that this system was thoroughly flushed through the boiler fill loop down separately the flow and return each having its own drain off.
Filled up with hot (showing 45C once in the pump) supply from combi and turned on. Water went straight to black. So PF and hot over mains cold is a clear winner.
Having dumped back to clear water, the Ferroquest didn't create the same drama (even when up to 55C) but this system has no old rads, the only old being in total about 35m of 15mm which made the amount of dirty water surprising.
I accept that the mains flush wasn't following a 'used in the system' chemical, which would be far better than just mains, but I'm a happy bunny for my £1200+. Magnaclean next I suppose at what, another £250?
My prices have just gone up!!!!

 

[NOTDIYFROMHELL]

Thanks for all the reply.

Taking into account of factors such as cost, effectiveless etc. I know what my preference is and no it won't be that bulky machine.

I hope whoever reads this topic will find it useful.

Topic close.

 

[ChrisR]

ChrisR wrote:
Where it does matter though is in primary sides of 2ndry h/e's

Agreed, but as you've probably noted elsewhere, this is the one part of a combi boiler that is not normally treated in power flushing, since the diverter valve will not allow circulation through the secondary h/e from the CH pipes.

And I have explained that more than once before. But the stuff on the insides of the radiators is exactly the same which will clog a clean dhwhe.

If you flush a system with water, add inhibitor and run it you will get magnetite flake deposits on the primary side of a cleaned dhwhe, even if there's a filter in the return. So it would seem to be best to be rid of as much of it as possible?

 

[chrishutt]

even if there's a filter in the return

I don't see how iron oxides particles, especially "flakes of magnetite", can possibly pass through a sufficiently fine filter. The filters I use would certainly stop it.

In any case, I normally find oxide flakes collecting even after chemical cleaning. The cleaning seems to weaken the bond between the oxide and the radiator/pipe walls so increasing (or even creating) the subsequent problem.

 

[NOTDIYFROMHELL]

I don't see how iron oxides particles, especially "flakes of magnetite", can possibly pass through a sufficiently fine filter. The filters I use would certainly stop it.

What filter do you use/recommend?

Cheers.

 

[Slugbabydotcom]

I use this method frequently but kept it quiet because strictly speaking it may not comply with the water regs. The bit about preventing waste or misuse.
A Flowerpusher recycles the same water therefore using less.
Another water wasting trick I have used is where the feed pipe on a conventional system is blocked is to connect a hose to the vent pipe and turn on. Just let it run out of the overflow for half an hour or so.

 

[ChrisR]

ChrisR wrote:

even if there's a filter in the return

I don't see how iron oxides particles, especially "flakes of magnetite", can possibly pass through a sufficiently fine filter. The filters I use would certainly stop it.

In any case, I normally find oxide flakes collecting even after chemical cleaning. The cleaning seems to weaken the bond between the oxide and the radiator/pipe walls so increasing (or even creating) the subsequent problem.

I know this is an old thread but since it has been referred to recently I'll answer that point made.

Judging by whay I have found, and supported by others' findings, if magnetite is left in the rads, especially if it has been disturbed, it will get round the system as tiny particles. It will clog a fine filter. It will also pass through a fine filter and deposit on the insides of the primary side of a plate heat exchanger - making big flakes.

Obviously, big flakes of the stuff won't go through a fine filter.

To be specific, if you use a standard 22mm Y strainer you get two flters. If you leave the finer one in it will clog up. But enough still gets through to line heat exchangers.

If you use chemicals of course you will dislodge flakes of stuff from the surfaces they are in contact with. This is the problem with putting a chemical in then just draining, or just squirting the mains through the bottom of a rad - you will leave a lot behind. That is where flushing machines come in. You don't remove it all but by concentrating on one rad and reversing the flow a lot and using mechanical means such as air injection and sds drill derived vibration, you get more of it out. Fernox only claim 80% though.

 

[Agile]

Only two points as my screen name was mentioned in the beginning!

Power flushing by independents is £250-£450 and definately NOT £400-£600.

Chris Hutt has apparently not yet bought a power flushing machine. Soon when he gets one he will realise that they do get more debris out of a system. If he was closer I would lend him one of ours!

Tony Glazier

 

[chrishutt]

Chris Hutt has apparently not yet bought a power flushing machine

True. Why would I when I fail to see any significant advantage over a combination of mains flushing and circulation of chemicals by system pump? One can even rig up a 4 valve manifold to allow reversal of flow during cleansing and flushing.

With regard to ChrisR's comments above, I am tempted to try a Magnaclean type magnetic "filter" which would presumably remove even the finest iron oxide particles. I take his point about subsequent deposition on heat exchangers, etc. after cleaning.

 

[NOTDIYFROMHELL]

ChrisR wrote:
... This is the problem with putting a chemical in then just draining, or just squirting the mains through the bottom of a rad - you will leave a lot behind....

ChrisR,

Does the water not force the magnetite flake from the primary plate heat exchanger if the main water comes in through the filling loop via the inlet pipe? I had my return pipe close to stop any rubbish re-enter the boiler.


Cheers.

NDFH