Is a powerflush the answer?

[Michael Rosen]

We have just had our boiler serviced and the water was a disgusting black - it clearly does need a powerflush which he said he would do for £400. (8 radiators)

However my worry is that the pipes and radiators are old and the powerflush won't really get rid of all the sludge and that some of the radiators should be manually emptied. Also, about 5 years ago we had a leak in pipes which we could not find and which seems to have been solved by putting some solution into the system. I am worried about potentially causing another leak if we powerflush.

So my question is not whether the powerflush is needed -it is. It's whether or not I am opening myself up to potential further costs if it is to be done properly. Looking for advice on the cost/benefits I guess.

 

[terryplumb]

Do you have a magnetic filter ?
Do all radiators heat up well and fairly quickly ?

 

[Michael Rosen]

Yes i have a filter. It was actually fairly empty of rubbish and sludge when he cleaned it.

The radiators all heat up well apart from one which clearly needs bleeding but the outlet is all painted over so I can't open it.

 

[terryplumb]

Forget the powerflush ,just add a proprietary chemical cleanser. Follow the instructions as to how long to leave it running round the system before manually flushing out.
With regard to the rad that you can't bleed ,post a pic of the air bleed valve ,then suggestions can be offered on what to do with it .

 

[Michael Rosen]

Thanks - photo attached. What cleanser would you recommend? I am sure it is easy but fear I just wouldn't know how to administer and flush it out safely, and don't want to do any damage

 

[terryplumb]

Sentinel X 800 cleaner.
Can't tell if the bleed valves are still square shaped or if it's been rounded off ,but a brass bleed key tapped into them will probably work. People tend to overtighten them and it's really not necessary.
If your system is fed from a small expansion tank in the loft ,the cleaner can be added there ( after draining some water out first). If your system is sealed / pressurised there are other ways to introduce it.
You can't really do any damage draining a system.

 

[ianmcd]

Sentinel X 800 cleaner.
Can't tell if the bleed valves are still square shaped or if it's been rounded off ,but a brass bleed key tapped into them will probably work. People tend to overtighten them and it's really not necessary.
If your system is fed from a small expansion tank in the loft ,the cleaner can be added there ( after draining some water out first). If your system is sealed / pressurised there are other ways to introduce it.
You can't really do any damage draining a system.

Sorry not often I disagree with @terryplumb , but I wouldnt put X800 anywhere near that system , your radiators will pinhole and you will knacker your pump, use X400 it is much milder, X800 is far too aggressive

 

[terryplumb]

Sorry not often I disagree with @terryplumb , but I wouldnt put X800 anywhere near that system , your radiators will pinhole and you will knacker your pump, use X400 it is much milder, X800 is far too aggressive

You basing that on the condition of the pictured radiator Ian ? Just took a closer look at it and I am thinking your right

 

[Michael Rosen]

Thanks for your advice Ian and terryplumb. I am sure it is very easy and failsafe but I just have no idea what I am doing and for peace of mind I'll have to pay for a powerflush.
The valves have been slightly rounded off and there is a build up of paint so the bleed key just can't grip very well.

 

[ianmcd]

You basing that on the condition of the pictured radiator Ian ? Just took a closer look at it and I am thinking your right

I never use it at all now Terry, I know Sentinell claim that they have changed the formula and it is not so aggressive now, but if you can not guarantee to get 100% of it out of the system afeter a very short period it will eat anything, the OP has already installed leak sealer and those rads are in very poor condition, X800 would pinhole that system all over the place

 

[gas112]

Those rads are 40 + year old It would be better investing the 400 quid in new rads

 

[Mottie]

I ended up changing my last 3 original 50 year old radiators after a powerflush and conversion to a sealed system as one of them leaked straight away and the other a week later. Whether it was the flush or the pressure that done it I’m not sure but as above, the money would definitely be better put towards a chemical flush, new rads and some inhibitor. My old rads got hot but the new ones chuck out much more heat so probably more efficient.