Powerflush, risky?

wersal gummage

Hi folks,

Grateful for any views. Long story here but leaving out all the unnecessary stuff...

New boiler and rads but several rads have the rainbow /arch pattern of hot at top and sides and cold at bottom and middle. Presumably full of sludge. New pipes were not installed on advice at the time that it wasn't necessary. It's copper from what I can see, not qualplex stuff.

Person who installed them won't come back but said over phone they deliberately didn't power flush when installing the system as risk of pipes bursting / leaks etc... Said rads need to be taken off manually cleaned outside with a hose etc....

Have rang one or two power flush outfits who are saying (over phone without looking at house) that it's 100% fine to flush etc... But I'm conscious they'll be gone and any leak then has me ripping out plaster or pulling up floors etc...

House is early 90s, standard enough.

Is a power flush risky?

Thanks

Alun

When I had my new boiler installed recently they did both those things, i.e. took all the radiators off and flushed them through manually outside with a hose and after reinstallation did a power flush as well. Our house also dates from the mid 90's and had never been flushed, so there would have been 25 years of accumulated gunk in there. Also got a magnaclean filter fitted. No issues with leaks fortunately.

Wearb

"New boiler and rads"

Unlikely the pipework held enough sludge to cause the problems you're having.

Do you have a solid fuel boiler also? Just trying to figure out where your sludge came from?

Alun

Aah, didn't see that he had had the rads replaced too.

wersal gummage

Wearb,

No we just have the one boiler, regular gas boiler. We have a wood burning stove but it's not plumed up or capable of such.

Sorry I may have given the wrong impression, the rads and boiler are in a few years now, less than 5 years. Initially all but 2 rads worked, those 2 rads were always in that "arc" of hot at top and sides, cold in middle etc.... Work was done in the early summer so we didn't notice an issue for maybe 6 months.... Over the last 2 years or so those rads have improved somewhat (but still have that same pattern) and the issue has started popping up in other rads, but not all rads by any means. Maybe we have 4 or 5 now out of 15+ with issues. I'm assuming the sludge had moved around a bit...

We also got the magna clean yoke so hopefully the boiler is safe....

Wearb

With even 4 or 5 rads displaying such cold spots, I expect the magnaclean needed regular servicing.

Those same symptoms can also be caused by not having enough heat delivered to the rads.

Turn off 6 rads that a working well and see if the faulty ones improve after an hour of heating.

With a gas boiler, installer should never install without some sort of flush. Anyway try the above and see what happens.

wersal gummage

I have already tried that, the 2 particularly problematic rads don't heat properly when other rads in house turned off. They never have. They are next to each other on the system so to speak, in adjoining rooms. Radiators at both higher and lower levels of the house working fine so boiler is getting heat up beyond them to higher parts of house if relevant.

At this point I don't mind trying the power flush (which was not done when the new rads and boiler installed, I only found this out much later).

Just don't know if first guy is a cowboy for not doing it properly, or whether he was right to have concerns about power flushing in general. He had no specific concerns when I spoke to him, just a general statement that you never know what you're dealing with in a house and anything could happen.....

Alun

https://www.boards.ie/discussion/comment/119845668#Comment_119845668

I seem to recall when my Viessmann boiler was installed it was a condition of the manufacturer's warranty that a flush was performed and (I think) a magnaclean or equivalent installed too.

Wearb

Those seem to be normal requirements IF sending in the warranty form.

youtheman

It's down to what is the 'max pressure' that the powerflush pump will subject your system to. If it's less than the current operating pressure then there is absolutely no risk. If it is above then there is some risk. Ask the powerflush company this question.

Lenar3556

Hard to see there being such a level of sludge buildup in the course of 5 years, with a gas boiler.

It may just be a more straightforward circulation issue that needs be addressed. (Possibly pump issue, blocked filter or air in the system)

I would hold off on an aggressive power flush unless it is definitely required.