Chemical flush question

[Mottie]

I'm having a new boiler fitted on Friday and they are planning to start at 6.30 in the morning as boiler is in loft and it’s like a sauna up there. I want the system as clean as I can get it before the new boiler is fitted.

I had a powerflush about 18 months ago. Over the last few weeks I’ve removed my rads and flushed them out manually and added a bottle of X400 chemical flush last week. Because I’m not around tomorrow I was planning to drain the system down today, fill with fresh water, drain, fill and drain again.

May be a stupid question but will it be okay to leave the system filled with plain water for a couple of days or should I leave it empty?

 

[muggles]

Should be fine with plain water, although for peace of mind you could spend £10 adding a bottle of inhibitor...

 

[AndyPRK]

plain water will be fine for a few days. Will help flush out any more remains rather than leave dry

 

[Mottie]

Cobblers! Just drained it out, filled with fresh, just running it up and the plumber calls to cancel for Friday! To be fair to him he was booked to come today but I phoned him on Monday and said today was supposed to be the hottest day of the week (was over 40°C in the loft on Monday) and was okay with me if he puts it off till later. He checked the weather report and it was supposed to be cooler on Friday so we rebooked for then. Then the weather changed again. Supposed to be 36° on Friday now so really will be unbearable in the loft. I’ve put him off till after I come back from my hols in mid August now. He said it’ll be okay to leave fresh water in the system until then as he’s going to drain and flush anyway and he will add inhibitor etc as part of the install. I think I’ll chuck a bottle of inhibitor in to be on the safe side though. I know I’m going to get it in the ear from the wife for interfering but I just can’t help myself.

 

[AndyPRK]

I'm sure there are plenty of people who run plain water for years, with little problem

 

[ianmcd]

fresh water will be fine, your installer will add inhibitor anyway, you are just wasting inhibitor for the sake of it.

 

[Mottie]

Ok thanks. On my third flush and the water is still a bit cloudy so I’ve found a quicker solution. I’ve left the heating running, pump on max, drain tap cracked open, fill tap cracked open and I’m holding it at 1.5 bar. The water coming out is warm so it’s obviously going round the system so I’m going to keep running it until it runs clear.

All clear now. Might not be getting the new boiler fitted for a month now. Leave just plain water in the system or chuck some inhibitor in? It’ll only be circulating the heating coil until then. Not bothered about the boiler. I have a mag filter fitted but will my rads start corriding internally in a month? I don’t want any **** in the system when the new boiler is fitted.

 

[ianmcd]

if you keep constantly flushing your system you will cause corrosion, you are determined to add inhibitor so do it then leave it alone.