help! do we need a powerflush?

[pegassus]

Hi please help anyone!
I have no plumbing knowledge so simple answers would be apreciated!!
3 of our 4 radiators are virtually stone cold as are the pipes leading to them. 1 is hot!
when we ve tried bleeding them the water is clear. However water in the pump in the combi is
black. Theres also a horrible screech from the boiler when we run the hot water tap from the bath upstairs.
2 companies we ve asked about a power flush said we did nt need it and theyd just be ripping us off as its a boiler problem. but british gas who we have homecare cover with have said its definitely a block somewhere and only a power flush will sort it.
Please can anyone help us with this? power flush or not!?
Helen

[WILLWONKER]

I take it that your homecare with BG does not cover power flushing? and yes i,m afraid to say that these days BG will rip you off if they can, i would try and get yourself an independent plumber who will give you a free quote for work required, power flushing has become a big earner and in many cases a big sam for BG, now i,m not saying it dos,nt need cleaning, but if it does it will be a lot less from a one man band that wants to keep your business.

[Hymie]

I would say that you have two separate problems:-
One, the screech with hot water demand (running bath water), the other the cold radiators.

Is the screech constant during the whole time the bath water is running, or only short lived for a few seconds?

Your cold radiators could well be a result of crud in the system, which will be cleared with a power flush. Since British Gas claim a power flush will sort it – could you not get an agreement from them that if after the power flush, all the radiators do not reach full heat – you will not pay them for the power flush? You will then find out how certain they are that it needs a power flush. Bear in mind they will charge over £400 for this.

Other than the above – get yourself a rubber mallet and give the pipery around the non working radiator valves a gentle bash – which may dislodge anything blocking the valves.

[pegassus]

Thanks for advice- the screech lasts a few seconds and then starts over. This repeats til we turn off the taps. We get the same noise if the dial for the central heating on the combi is turned up full.if the radiators were full of gunk shouldnt the water from them be black too?
Helen

[buildersmate]

It is simply untrue that Power Flushing is the only way to remove sludge. Power flushing has only been on the scene a few years, whereas CH has been around in volume use for over 40. Power flushing just happens to be a nice convenient solution that heating companies just loooooooove to sell you.
The alternative a chemical such as X400 from Sentinel (Advertising Stds Authority warning: other chemical cleaners are widely available). This is the generic website for this company and the chemcials are widely available from plumbers merchants (and even the DIY sheds these days).
http://www.sentinel-solutions.net/
The trouble with chemical solutions is that they take time to work - meaning multiple visits from a heating company - hence they don't want to use them because every visit 'costs' in travelling time for them.
Black colouration in the water is a sure sign that your radiators are being eaten alive from the inside - you won't see the colour when you try and drain from the top because the sludge is a heavy suspension of iron oxide in the water and it generally sinks to the bottom - where it sits, preventing water circulating.
Once cleaned and washed out, replacement inhibitor (normally X100) should be installed to prevent future sludge formation.
The cost for the whole lot? - less than £40 I guess, plus some time and a bit of mess. How many hundreds are you being quoted for power flushing? What rate per hour do you get paid? How many hours of work would you have to work to pay for a powerflush? It's a no-brainer.

[pegassus]

This is great info for someone like me! Thanks for this. its really helpful. Yeah british gas want about £600 for the 4 radiators so would definitely be looking around elsewhere as power flush does nt get covered in the home care package.
Helen

[Hymie]

Without hearing the screech it is difficult to say which component is at fault – but from what you say, I would hazard a guess that it is from the fan – with the blades in contact with the fan housing (until it gets going). This could be due to the bearing on the way out – eventually the fan will fail – resulting in the boiler failing to ignite. But before that happens, I would expect the noise to get even worse.

You could try buildersmate’s advice of trying additives – but it is not a simple matter to add 500ml to the system (as some would have you believe).

[WILLWONKER]

Do you not just drain the system from the lower point radiator add the cleaner too the header tank and then refill, expell air, leave to clean for a week, drain down again and add inhibtor too header tank refill again and so on as above, also if you are really brave after the first week of cleaning take your lower rads off as most of the crap wil be in these rads and take outside to empty the black slush out. flush out with hose pipe and refit, in fairness BM did say it,s not going to be a walk in the park but neither is paying £400/500 if you are a DIY then give youself a day to do it, if you don,t know how to do it there are plenty of DIY books that tell you how

[Hymie]

Willwonker’s method will work if you have a header tank – but if you have a sealed system, it is not that simple – but worth the effort for £400.

I would concur with Willwonker, if you can drain down the system and remove the radiators – they can be flushed through in the garden using a garden hose. It really is not that difficult, you only need the correct spanner(s) and a roll of ptfe tape.

[pegassus]

Thanks for your help everyone! Its much appreciated
Helen

[Surreyplumber]

The only real way to no if you need a power flush, powder flush or pellet flush is to have the central heating water tested. Have a look online, you can have it done for free or at very little expense. Even if you try a power flush it might fail to clear the block, while powder flushing or pellet flushing clean the hardened sludge much better.