Cleaning solution flush

[gazdkw]

Hi all,

First Post on here. I am hoping someone can help with the below.

I have mounted 2 new rads to a recent extention we have had. The rads are not connected up to the heating system which is a combi fed system.

I thought it would be good practice to clean, flush, refill and use an inhibitor when filling up with the new rads connected.

I purchased a flomasta clean and inhibitor kit from screwfix and put the cleaning solution in 2 days ago.

I plan to flush the cleaner out on monday/Tuesday but I am unsure how to flush it out. Is it a case of numerous drains and refills? Is there a way to isolate the boiler and use the filling nozzle built into the boiler to flush the rads (I have a drain valve on the lowest rad downstairs)

Any help would be great. Thanks

 

[Knappers]

Yes filling, running and then draining system thoroughly twice should do the job.
I tend to flush the way I'd call dynamically where I leave filling loop on and set drain off to a point that boiler maintains a reasonable pressure (say 1bar) then just leave it and get on with something else for a while

 

[Ben-gee]

It’s worth shutting up off all the rads except one and just flushing with mains as knappers says above.
Flush for a few minutes after the water had run clear, then close that rad and open another.
If you don’t do this you may find the flush takes the easiest route and some rads are not cleaned very well at all.

 

[Knappers]

Maybe but id worry you could just get cold flowing across bottom of rad. I like to have heating on and balanced rads. If they're all a bit warm then I know they're all flushing.
Horribly wasteful way to do it tho and just draining and filling is probably best, just need to make sure you drain all the drops.

 

[Ben-gee]

Fair enough, but to be honest all the crap is at the bottom of the rad so if it were flowing just there would probably do a pretty good job!!

Like to see a bit of muck coming out then running clear, you know you’ve done something then- and you’re right a hot flush is better (unless it’s my missus having it!!!)

 

[Knappers]

Oh OK... yes, for flushing dirt.
I'm thinking purging system of chemicals.
...
Could flush with mains via filling loop and even add in some agitation of rads with a rubber malet or something vibratey?
Make sure your not flushing dirt through boiler or pump tho!

 

[gazdkw]

Oh OK... yes, for flushing dirt.
I'm thinking purging system of chemicals.
...
Could flush with mains via filling loop and even add in some agitation of rads with a rubber malet or something vibratey?
Make sure your not flushing dirt through boiler or pump tho!

How do I ensure I'm not flushing dirt through the boiler?

Is there a way to bypass the boiler and flush via the filling nozzle on the boiler itself?

Quite happy to do numerous drains via the lowest rad and refill etc but I would like to know iv gotten all the cleaner out.

I have heard some inhibitors neutralise cleaners but I can't see any information on them to suggest they do

 

[Knappers]

If your goal is just to remove chemicals then just draining twice inc any separate legs is prob your best option.

 

[gazdkw]

If your goal is just to remove chemicals then just draining twice inc any separate legs is prob your best option.

Sorry to ask probably a basic question but what is a separate leg?

 

[gazdkw]

I just drained the system and refilled but came across some problems.

The system drained fine. I slowly opened bleed valves from upstairs to down. The system completely drained.

I think refilled system to about 1.5bar and went around bleeding rads. I kept topping up the pressure as it dropped when bleeding. On the last rad to bleed I topped up but the flow from the boiler feed valve seemed to stop at 1.5bar which was odd.

I turned the boiler on and it seemed to make alot of gargling and air bubbling noises. I tried running the hot tap and it seemed to work for a short time then kept clunking and gargling water etc.

I have let it settle, bled last rad and now the filling valve seems to work again. Topped up to 1.8bar.

Ran the hot tap and it seems OK, although there is still some small bubbling and gargling noises.

I need to do another drain and refil but I am unsure why this happened and nervous to carry on incase I damage anything.

Can any advise?

 

[Knappers]

It sounds quite normal, I wouldn't worry

 

[gazdkw]

So the boiler should bubble, gargle after refilling?

Plus, it kept initially stuttering when running the hot water after refilling, is that normal?

It's working fine now though so I can't have damaged anything

 

[gazdkw]

I have completed a 3rd drain but the water still seems a little murky. How clean is it meant to be?

the colour is slightly darker than apple juice

 

[Chuck]

I have completed a 3rd drain but the water still seems a little murky. How clean is it meant to be?

the colour is slightly darker than apple juice

You might find this helpful, illustrates use of turbidity test tube in the first section:

 

[gazdkw]

Thanks, looks like I'll be buying a vastly overpriced turbidity tube.

On another note, iv done the final connections on the 2 new radiators. System all filled up and all bled. 2 new radiators are not as hot as any of the others. Both trvs are fully open, installed on the flow side. Both lockshields are fully open. Pressure is up to 1.8bar.

Can anyone help diagnose why? Only difference I can tell from all other rads is that they are pipped in plastic for about 4/5 metres and then copper for the final section that comes from floor/wall.

One of the new rads is a 1400x600 type 22. It should be very warm.

 

[Ric2013]

In a nutshell, a TT test will only tend to pass if the water seems to be very clean when looked at in the normal way. In my limited experience of using TTs, anyway.