Flushing CH system after X400

[richig]

I have had X400 in our open system for a month now and its time to flush the system and add inhibitor. Is it ok to use the following method?

Connect hose to the drainoff point on the radiator downstairs, open the valve and allow the water to run clear.

Or should I isolate the FE tank and drain and refill the system until the water is clear.

Then add my inhibitor.

I feel that it would be easier to use the first method and just allow the water supply from the FE tank to run through the system and out of the drainoff until clear instead of the more time consuming draining and refilling several times.

Any thoughts/advice

 

[Agile]

I agree that to run out as it fills is better.

But that's mostly because done properly it will not create any air problems.

But you must run out SLOWER than it refills.

Also you need the pump ON as you do this.

All depends on your system but should be possible to arrange to run pump without needing the boiler on. But the motor valves need to be in manual locke positions!

Tony

 

[richig]

I agree that to run out as it fills is better.

But that's mostly because done properly it will not create any air problems.

But you must run out SLOWER than it refills.

Also you need the pump ON as you do this.

All depends on your system but should be possible to arrange to run pump without needing the boiler on. But the motor valves need to be in manual locke positions!

Tony

Thanks. Bit unsure how to make the pump run with the boiler off - is it essential for the pump to be running? I have an S plan wiring layout if that applicable?

 

[JohnD]

unless you baled out the F&E before you started, it is probably full of sludge, fungus and drowned wildlife. It is not helpful to run that into the system so bale it out into a bucket and sponge it clean.

 

[Agile]

It is essential otherwise all you will flush out are the direct path between feed and drain.

Not only must the pump be on but all rads turned on as well.

Tony

 

[richig]

It is essential otherwise all you will flush out are the direct path between feed and drain.

Not only must the pump be on but all rads turned on as well.

Tony

Thanks. To clarify I have 7 rads in total (small semi 2 bed detached house) - 4 upstairs and 3 downstairs. All three downstairs have drain offs.

As an alternative to running the pump could I go around each of the downstairs rads in turn flushing water until clear (with valve in manual position)?

It may also be of not that I have a combined feed/vent pipe with air separator fitted though I drained the system down and refilled about a year ago with no problems. What I am really trying to do here is flush to save time and avoid air in system as Agile says.

 

[DP]

Richig, only way to flush the system is fill, vent, drain and evacuate/ empty the system, several times

You have got X400 cooking in the system for a month. It is everywhere- base of radiator, middle and top too. Now, by all means drain as header fills. All that will happen is clean water enters the radiator, flows across the base rib and comes out the opposite end to then flow out of the drain point

You eventually see pristine clear water flowing out. BUT, water with X400 remains untouched in area ABOVE the base rib

 

[JohnD]

If you can afford the time and money to fit a system filter, you will be gratified to see that it continues to collect sludge for quite a long time, even after you think you have drained thoroughly. The x400 loosens it.

The amount gradually reduces, as it is trapped and you clean it out, until, eventually, you only need to clean it once a year and there is just a smudge of sludge.

 

[james0james]

Is your system operating better than when you inserted x400 best to test before assuming all is ok,just to reduce time and future expense.
Check all visable pipe joints fittings rad valves etc in case x400 has removed crud which was previously sealing water leaks,do before draining down and repair any leaks before refill.
Check your air separator is not restricted before refill.
Clean expansion tank,scrub it clean and don't let debris fall into system.
Personally I would leave x400 in the system until it has had a good chance to circulate,maybe 4 weeks of winter circulation. x400 can be safely be left in the system for ever.(APMI).

Good luck.

 

[JohnD]

but it does gradually lose its cleaning power, and the sludge re-settles.

IIRC 4 weeks is recommended as the longest time (hence the most thorough clean) before the power starts to diminish. The makers say (it is not an aggressive chemical) that it will not damage the system if you leave it in for ever; but of course if you don't drain it out, you won't drain out the sludge it has loosened.

Some of the other cleaning chemicals are aggressive, some are acids and actually eat holes in things (I have the pictures to prove it). Professionals sometimes look down on it but IMO X400 is especially suitable for DIY use as it is most unlikely to do anything but good.

As a DIYer I used it in my very dirty system with old iron boiler, flushed very thoroughly, fitted a Magnaclean to capture the residual particles, kept cleaning it until there were no more. Later the system was powerflushed at boiler change, and there was hardly any dirt.

 

[Agile]

Most consider the X400 needs a minimum of four weeks and that six is better.

But leaving for over six weeks risks depositing dirt back again so I would say it should always be removed by six weeks.

Tony

 

[Agile]

You would see that Kamco have "borrowed" my words and description of "dynamic flushing" to describe flushing as above.

But it does need to be done with the system pump or a power flushing pump on to ensure there is good circulation through each radiator.

Kamco have a glass radiator for exhibitions so you can see the movement of the dirt through it.

Tony

 

[DP]

You eventually see pristine clear water flowing out. BUT, water with X400 remains untouched in area ABOVE the base rib