Should I give the central heating a flush?
Discussion
Couple of years ago I called our Britgas insurance out as the CH pump was noisy. Cheeky eedgit told me he wouldn't change it as the system needed a powerflush, £750 he quoted.....
He also demonstrated to me how the system was lined with rust, as magnet would stick to the copper pipes near the pump and divertor v/v.
Anyway, being cheap, I simply added several litres of system cleaner/lube. Noise went away for a year. Last winter I did it again, but now it is being noisy yet again, making various rumblings and wooshing noises. Is it time to actually run a proper cleaner flush through it and drain/fill it with clean water?
Plan is to probably swap it all out for a combi boiler this year, so maybe I best just leave it until the next 'barbecue summer' starts in March and it isn't required.....
He also demonstrated to me how the system was lined with rust, as magnet would stick to the copper pipes near the pump and divertor v/v.
Anyway, being cheap, I simply added several litres of system cleaner/lube. Noise went away for a year. Last winter I did it again, but now it is being noisy yet again, making various rumblings and wooshing noises. Is it time to actually run a proper cleaner flush through it and drain/fill it with clean water?
Plan is to probably swap it all out for a combi boiler this year, so maybe I best just leave it until the next 'barbecue summer' starts in March and it isn't required.....
King Herald said:
Couple of years ago I called our Britgas insurance out as the CH pump was noisy. Cheeky eedgit told me he wouldn't change it as the system needed a powerflush, £750 he quoted.....
He also demonstrated to me how the system was lined with rust, as magnet would stick to the copper pipes near the pump and divertor v/v.
Anyway, being cheap, I simply added several litres of system cleaner/lube. Noise went away for a year. Last winter I did it again, but now it is being noisy yet again, making various rumblings and wooshing noises. Is it time to actually run a proper cleaner flush through it and drain/fill it with clean water?
Plan is to probably swap it all out for a combi boiler this year, so maybe I best just leave it until the next 'barbecue summer' starts in March and it isn't required.....
After you flushed the system, did you add a corrosion inhibitor?? If you flush the system with a good flushing agent, then add a good inhibitor, you shouldn't have any problems for a good few years. Most say 10 years. Any plumbers care to comment???He also demonstrated to me how the system was lined with rust, as magnet would stick to the copper pipes near the pump and divertor v/v.
Anyway, being cheap, I simply added several litres of system cleaner/lube. Noise went away for a year. Last winter I did it again, but now it is being noisy yet again, making various rumblings and wooshing noises. Is it time to actually run a proper cleaner flush through it and drain/fill it with clean water?
Plan is to probably swap it all out for a combi boiler this year, so maybe I best just leave it until the next 'barbecue summer' starts in March and it isn't required.....
rash_decision said:
After you flushed the system, did you add a corrosion inhibitor?? If you flush the system with a good flushing agent, then add a good inhibitor, you shouldn't have any problems for a good few years. Most say 10 years. Any plumbers care to comment???
The one I added was a bit of both, designed to clean, lubricate and be left in the system. Thing is, how many times can you really add that sort of thing before you have some sort of vegetable soup coursing through your tubes.

If you know you've had rust floating around the system, it might be worth popping the pump out and making sure that the impellors are not choked with debris.
Also, have you considered fitting some form of 'filter' to catch as much cr@p as possible ? You can buy cheap in-line filters (fitted with wire mesh), or spend a bit more and get a MagnaClean.
Also, have you considered fitting some form of 'filter' to catch as much cr@p as possible ? You can buy cheap in-line filters (fitted with wire mesh), or spend a bit more and get a MagnaClean.
SS2. said:
If you know you've had rust floating around the system, it might be worth popping the pump out and making sure that the impellors are not choked with debris.
Also, have you considered fitting some form of 'filter' to catch as much cr@p as possible ? You can buy cheap in-line filters (fitted with wire mesh), or spend a bit more and get a MagnaClean.
I can have a look at the pump, as it has isolation valves on it. Might be worth a try.Also, have you considered fitting some form of 'filter' to catch as much cr@p as possible ? You can buy cheap in-line filters (fitted with wire mesh), or spend a bit more and get a MagnaClean.
Not sure if I want to go to the expense of a Magnaclean, as I'm planning to possibly change the system over later this year, but I may strap a magnet to a short drain tube stub near the boiler, see if that attracts any floating magnetic passers-by.

King Herald said:
I can have a look at the pump, as it has isolation valves on it. Might be worth a try.
It worked for us - we had all manner of muck being pumped around our system (long story, but caused by plumber who fitted a replacement pump the wrong way round) and when the system got 'noisy', it was invariably down to clogged blades within the pump.SS2. said:
or spend a bit more and get a MagnaClean.
When we moved into our place we took out a British Gas contractmatey came out and said that before it would be taken on contract, the boiler actually needed about £190 worth of parts (new Heat Exchanger, Divirter & pressure release valve)
Well I wasn't not going to pay (I like a quiet life and the Mrs feels the cold), but as an added sweeter (and I wonder what he made out of it) he said that if British Gas installed a MagnaClean and we paid for it (it was the same cost of as the parts that were needed) - we could have the needed parts & fitting costs for free.
When he pulled the old heat exchanger out, it was filled with s
t - and he took the divirter apart too - ditto, filled with crap.With luck the MaganClean will do the job!!
LC926 said:
a guy at work was telling me he paid £400 for a power flush and system balance, he has a 3 bed semi. He reckons its the best thing he ever did, he says boiler isn't turned up as high and the rads are really hot and much quicker.
The guy who will probably be doing the combi boiler install said he'd do a power flush if required. If the copper pipes are magnetic it indicates there must be a fair bit of the old ferrous oxide/scale coating on everything. Plus, I'd guess our current boiler is 20 years old if it's a day.
Wings said:
Incidentally have you heard about the £400 grants being given out against fitting new combi boilers?
Oh yes, saw it in the paper a few weeks ago. Reckon I shall take advantage of the scheme. 
I'll see what the plumber says about the power flush, but I guess it is good sense to do it when the system is being overhauled.
British Gas are famous for recommending powerflushes, a very bonus-heavy product. They will charge at least twice as much as other people, who will tell you if you *actually* need one or not (Most dont).
You can tell if you need one - the bottom couple of inches will be a little cooler than the rest. Then drain a jam jar full of water from the rad with a drain. If its brown water its OK, if sludge comes out, then probably does.
Easy to do yourself, and then you'll get the proper inhibitor as well, which BG often charge for but 'forget' to add.
You can tell if you need one - the bottom couple of inches will be a little cooler than the rest. Then drain a jam jar full of water from the rad with a drain. If its brown water its OK, if sludge comes out, then probably does.
Easy to do yourself, and then you'll get the proper inhibitor as well, which BG often charge for but 'forget' to add.
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