Hi

Had a leaking valve in the house radiator system this week. British Gas guy comes around, produces a magnet, waves it around and says this proves the system is full of sludge and we need to pay a large amount of money for a system flush'.

Is this likely to be true or is it yet another 'hard sell' technique from BG ? I question it becasue a friend also had a problem with his central heating las week, that was not related to our fault and the BG engineer when though exactly the same 'magnet' and 'you need a system flush' statement.

Anyone else had this or is it just honest co-incidence? In all the years we have had radiators, I have never come across the 'magnet proves all' thing before.

Where does he wave his magnet and what are the results?!

When I had my new boiler put in last year, the guy pushed very hard to sell me a "Magna-clean", which is a plastic can containing a giant magnet which supposedly catches sludge in the system before it gets into the boiler internals. He serviced the boiler last month and cleaned out the Magna-clean.It was amazing how much sludge the magnet had picked up.

I'm sure they are hard-selling, and that anyone will do a cheaper system flush than BG, but I'm pretty sold on the need for them periodically. 🙂

Blaming sludge in the system seems to be a standard response.

We had a boiler that kept breaking. We had insurance, so they kept fixing it. Eventually, they declared it to be a problem with the system and so refused to repair the boiler. Strangely, the replacement boiler was absolutely fine…

Do you have the British Gas 3* plan thingummy? Power flushes are not covered on those, so are often 'required' by british gas.

Don't get me started on central heating flushes……grrr.

Our heating partially packed up (some rads working others not) just before the weekend – so I spent all weekend flushing / draining / refilling / getting rid of air locks etc and still the system is not doing what it should.

Some of our pipes are full of sludge as they're magnetic (shouldn't be as copper isn't magnetic and sludge is). I'm now waiting to book the plumber for a flush (£300 🙁 ) and maybe install a magna-clean (another £100+)

The magna-clean thingy looks pure engineering simplicity and looks like its won awards and got good reviews – just more cash I could without spending – but what price a warm wife 😯

One tip – DO NOT USE BRITISH GAS.

Now a little story:

At our last house we needed a full CH sysem installing, everything apart from hot and cold tanks. I went into a local plumbers who I knew were good and got 3 reccommendations for gas installers. We got all 3 round for a quote. All 3 were small local firms and gave quotes from about £3600 to £4300. All 3 came round, usually in working clothes, with a notepad and tape measure, and sent a proper written quote through the post. I'd ahve been happy to use any of them. A couple of people kept bugging us to try British Gas. So we did. Young bloke in a shiny suit comes round with a briefcase, takes literally a 2 minute look round the house and says "£6000. How does that sound?" So I showed him the £3600 quote. Never seen anyone look so ebarrased in my life. He scuttled off.

We're in a similar position right now, and doing the same thing.

Just don't use big chains for anything DIY related, unless it's just parts off the shelf at B&Q etc. Go to small local places for bathrooms, kitchens, gardens, drives, building work, everything. They live and die on service and quality. DOn't be swayed by posh suits and shiny showrooms. It's YOU that's paying for it. Get recommnedations, look around, and always get at least 2 quotes!

If anybody lives near Farnborough, Hants, I can happily point you in the direction of several decent tradesmen. 🙂

One tip – DO NOT USE BRITISH GAS.

+1
I had no end of trouble with them in my first (rented) house. Eventually I changed supplier and told the estate agents/landlord to change the people they used for boiler repairs.

Apparently he waved magnet up and down the radiator. I was not home at the time. Why is sludge magnetic? I thought rust lost its magnetic properties? If its not rust, what is it? – limescale has no magnetism.

I am not sure how this magnet thing works at all as the radiators are steel anyway.

Yes, the person who owns the house I live in does have a maintenance contract and the 'flush' would mean another additional payment to BG.

Yes, they did try to sell my housemate some magnetic filter thing.

I hate british gas, they become increasingly rubbish as greed gets ever more important than service. The engineers that call at the house seem mostly decent chaps though.

The newish boiler came from an independent company who did a great job at half the cost. My house mate wishes to stay on the BG service contract though and I have no say in that. Its not my house, its his.

British Gas and power flushes pops up on other forums quite often – seems to me that you're on a contract but they want to sell you an extra so they make more money out of you irrespective of whether it will help or not. So DO NOT USE BRITISH GAS. But I'm guessing that if you don't get it done then next time something goes wrong they'll say "it's because you didn't have a power flush and we're not covering it" so you're really tied into whatever price they quote !!!

You can DIY the power flush – it's not difficult so long as your follow the procedure. Also thread here

Oh, looked at Magnaclean (or one similar) a few years ago and I would go for one in any system from now on.

I hate british gas, they become increasingly rubbish as greed gets ever more important than service. The engineers that call at the house seem mostly decent chaps though.

couldn't have put it better myself and i speak as on of these "decent chaps"

BG are , like most big companies, greedy and aggressive in the market and as an employer

however they have one saving grace which is a highly skilled conscientious workforce of installers and service engineers so while i cant and wont defend BG business practice i still think they provide quality service

back to the OP depends where he was waving his magnet

radiators are magnetic anyway so that is bogus

copper pipes arent unless theres corrosion/ sludge but even then its not always conclusive proof

Likely to be marketing and related to the fact that some twunt invented the powerflushing device.

Anyway I've previously done it myself – non power flush (Fernox products – use flusher then cleanse with water then refill with inhibitor) on an open system(header tank). (All my rads have drain cocks thta I can fit a hose on). Not sure how good it is in comparison to a power experience but it cost me about 25 …..

a well installed and commissioned radiator system should never need flushing

at least not in the lifespan of a boiler (20 yrs?)

sludge is a symptom of a sick system so flushing will remove sludge but wont cure the root cause (system design/ leaks etc)

definitely worth flushing and fitting a magnaclean if youre having a new boiler/altering the ststem

otherwise try to find out whats causing the problem first

British gas will ALWAYS tell you a power flush is required.
Just a con really. Drain it slowly from a radiator so the header tank doesn't empty. Do that for 20 mins on each radiator. Then bung a bottle of sludge remover in it for a week. Do the above again. Then repeat. After the second time, it should be clear, then add a bottle of inhibitor.
If it's really bad, it could well need a powerflush. You can rent one for about 65 quid plus the cost of chemicals, or pay someone to do it. Should be able to get it done for about 150-250. Check ebay

Do Not under any circumstances use British Gas. Their sales people and the techniques they use are the lowest of the low. They practically forced my aging and not all together with it father to sign away £4300 for a new boiler and 1 radiator. Normal cost from any decent plumber would have been £2000. No wonder their profits keep rising.

As someone who has dealt with BG in a professional capacity (nothing to do with servicing boilers) I can safely say they are a bunch of sharks. Not much more so than any big company, but sharks all the same.

Generally the sales talk is always much better than the level of delivery.

Funny really considering that this is a company that's reputation is based on trust and integrity. Shame they got such customer loyalty, built partly on the "british" aspect of their name.

pipes copper, boiler heat exhchange copper..
CH pump impellor is normally alloy,
only the rad's will have any steel in them so what use is a magnet ?
modern practice of small bore pipes is more of a problem (but cheap to install).
get your system replumed with proper sized pipes (and no manifold rubbish) flush your existing rads and boiler and add some corrosion inhiitor to the system when you fill.

so what use is a magnet ?

sludge (magnatite) contains ferrous particles which are magnetic through copper pipe

Most likely a selling technique. Your system could well be suffering with 'sludge', but sometimes powerflushing will not work. I own a machine and do do it sometimes, but if a radiator is very bad, usually a triangular cold spot in the bottom middle section, than it most likely wont. You will need to take the radiator outside, use a hose to blast it, half fill it and turn it vigoursly a few times followed by more hose. They have started selling all sorts of attachments to go with the machines as they are finding that on their own they wont always work. Things like clamps to put on the radiator that you attach a drill to to vibrate the deposits loose.
If it is not that bad, generally you will be ok with a cleaner (only use Sentinel or Fernox products as some boiler manufacturers will not like some of the cheaper alternatives) and let it go round the system for as long as recommended, then a good flush with clean water and finally refill with corrosion inhibitor at the correct concentration.
Powerflushing is over sold, misused and seen as a cure all by some sections of the heating industry. if you are suffering with corrosion then you need to treat the cause as well, which is usually poor system design, particularly the cold feed and vent arrangement.
And the filters are good, but again they are being used to cure a problem that with good system design should not occur. Also go for a filter that has both a magnet and a mesh system, as the magnet will only pull out ferrous material, and not remenants of PTFE tape, copper fillings etc, that could all damage the system.

Good luck!

wonny j – Member
As someone who has dealt with BG in a professional capacity (nothing to do with servicing boilers) I can safely say they are a bunch of sharks. Not much more so than any big company, but sharks all the same.

As above I worked for BG as a service engineer and I was bollocked on a regular basis for not selling "giving best advice" BG products

Told em to stuff the job up there arse and collect the van after one "chat " too many

They promote scare tactics at team meetings and preying on the trusting and unsuspecting customers which boosts the engineers quodos points which gives gift vouchers etc in return commission bascically

I used to work for British Gas. Shocking.

Develop a relationship with your local independent heating engineer – and I don't mean start dating him.

[Edit – just read post above, similar to me. I couldn't get my morals and respect for other folk low enough to hit their targets.]

Waderider

Good man, morals will not make us rich but I can sleep at nights

Why is sludge magnetic? I thought rust lost its magnetic properties? If its not rust, what is it? – limescale has no magnetism.

It seems that the sludge is magnetic as it is not rust, due to it being oxidised in a reduced oxygen/slightly alkali environment. So testing the copper pipes for reaction with the magnet would suggest lots of sludge. However on the radiator it's utter tripe, as they're 99x out of 100, steel and the magnet would stick.

Father in law needed his heating system flushing. He is into BG big time with all sorts of contracts and warranties. Can't remember what they quoted but I've got a mate who runs a central heating company and they quoted half the price. Unfortunately BG had put the fear in my father in law by hinting at void warranties etc if the work "was not up to their high standards". Irony of the situation was tha BG had been onto my mates company offering a sub-contract out the work of flushing systems to him.

I'm glad I wasn't the only person to avoid BG like the plague……. 😐

coffeeking – Member

Why is sludge magnetic? I thought rust lost its magnetic properties? If its not rust, what is it? – limescale has no magnetism.

It seems that the sludge is magnetic as it is not rust, due to it being oxidised in a reduced oxygen/slightly alkali environment. So testing the copper pipes for reaction with the magnet would suggest lots of sludge. However on the radiator it's utter tripe, as they're 99x out of 100, steel and the magnet would stick.

Nope still don't get it. Yes the water will have some iron(II) and iron (III) in it but if it is alkaline then they will come out of solution as the hydroxides, this precipitate is not magnetic. This reaction will be preferential to any reduction the iron ions may undergo.
If those conditions gave iron then we wouldn't be spending billions a year on smelting plants we'd just have massive radiators keeping the world warm and dropping out iron.