Totally non boaty....power flushing the heating system

Fascadale

Fascadale

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Our twelve year old boiler: hot water and heating, a "system" boiler needs to be replaced.

The quote incudes this statement,

"Note: As per manufactures instructions we recommend that when replacing the boiler the existing central heating system should be cleaned out internally using a power-flush machine and a cleansing agent"

They want just under £500 (inc VAT) to do this. Eleven radiators.

Is this money well spent? How necessary is "colonic irrigation" for a heating system?
 
To save on it you may just disassemble something and check the insides. May happen to be OK, depends what fluid was in it, and was it replaced often or not. Some 'mud' will be in probably, flushing it out is easy. Flushing can be made with any decent pump, water pumped 'backwards'.
To descale (calcium) there are special chemicals on market, but citric acid (in water) can be used as well in most installations, in fact probably the safest stuff to use. It also softens the water, so then any detergent can be added so to wash the insides better.
 
Fascadale said:
Our twelve year old boiler: hot water and heating, a "system" boiler needs to be replaced.

The quote incudes this statement,

"Note: As per manufactures instructions we recommend that when replacing the boiler the existing central heating system should be cleaned out internally using a power-flush machine and a cleansing agent"

They want just under £500 (inc VAT) to do this. Eleven radiators.

Is this money well spent? How necessary is "colonic irrigation" for a heating system?
Click to expand...
Lounge :rolleyes:
 
Fascadale said:
Our twelve year old boiler: hot water and heating, a "system" boiler needs to be replaced.

The quote incudes this statement,

"Note: As per manufactures instructions we recommend that when replacing the boiler the existing central heating system should be cleaned out internally using a power-flush machine and a cleansing agent"

They want just under £500 (inc VAT) to do this. Eleven radiators.

Is this money well spent? How necessary is "colonic irrigation" for a heating system?
Click to expand...

After twelve years the system will almost certainly have crud it unless inhibitor has been introduced at regular intervals, £500 seems excessive if they are there replacing the boiler anyway but it is a really good thing to start out with a good clean system. They will introduce inhibitor once the job is done, if you want the best from the new system you can get a pressurised can of inhibitor to introduce through the filling loop every couple of years, it's a fifteen minute job and requires zero skill. Or if you have a regular boiler service ask the servicing people to bung some in at the same time.
 
This process has come to be excepted as the norm wheather needed or not. The engineers (so called) like doing it because it is easy & a nice little money spinner. Most of the time it is just not needed.
Check you CH water. If it is dark black and contains sluddgey deposits then it is worthwhile having it done. If not forget it.
Note this is a recommendation and in no way a requirement within the guarantee.

Incidentally, why does your 12 year old boiler & system require replacement ? I ask because I have seen so many con-jobs over the years where peeps get told their boiler needs replacing, obsolete, cant get spares, condemned, etc etc
You sure it needs replacing ?
 
I did have a fifty year old system "power flushed" and it was amazing to see the crud that came out of it. It certainly didn't cost me £500.00---from memory it was a little less than £200.00. I also had one of these fitted
http://www.screwfix.com/p/adey-magnaclean-professional-22mm/88402

I am rather sceptical about their claimed 6% reduction in bills but it is easy to clean out and does appear to grab hold of all the bits of rust that are inherent in such an elderly system
 
Been running anti freeze mix 50/50 in mine for over 15 years, drained and changed it again the other week was still clean, did notice when i removed a rad a few months ago a tiny amount of silt in the rad and that was it.
My father in law has been doing this for well over 35 years and i think all his system is original, pipes rads etc.


Lynall
 
No manufacturer to my knowledge instructs that a system should be "powerflushed". The requirement of the Benchmark system (a log book for the boiler) is to state what cleanser and inhibitor have been used - no mention of powerflushing. Some manufacturers are very quick to blame a dirty system on warranty call out faults. I'm surprised that the company showed this as a separate item (unless their operatives drive blue vans!) ; I normally include any required system cleansing in the total price.
 
The biggest problem with "new" style condensing boilers is the sediment ( magnetite) from the steel radiators contaminating the high efficiency heat exchangers. This will produce noise which will sound throughout the heating system. Normally this sediment is caused by the heating system not being installed correctly, that does not mean that the system has not been working adiquitly

As previously stated "it may not be" necessary to power flush the system, but given that most manufacturers will not honour the guarantee if it hasn't been done the best heating companies will go through the process of doing it to remove any sediment so as not to fall foul of the manufacturers guarantee. That said £500 seems a little excessive but it will depend on what condition the system is in to start with.

Bear in mind that heating systems are, regardless of what many think, more complex than appreciated. My advice is to find a good heating company that has fully trained staff that are prepared to give good advice and back up ! For some reason there are pipe stranglers out there that think they can call them selves heating specialists. You will find some great advice on here and some that is........well lets say not as good.

Tom.
 
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The whole question depends on what system, what made of, what fluid, what boiler.
For comparison:
Here we have -30'C winters, and central heating high power going for 8 months a year, so bit different I recon ;) I just changed boiler for this winter, from condensing to condensing, 10 years old.
Piping copper, radiators mild steel, boiler exchanger stainless. System is filled with prop glycol kind fluid (antifreeze - which should theoretically be used only 3-5 years). Theoretically this system should be "flushed out" but in fact such procedure wouldn't be of much use due to complexity of system.
Instead bigger pump was connected into and fluid pumped for couple hours through big filter, the kind used for domestic water supply. Faster flow did remove quite a bit of mud, fluid after filtering was deemed OK by specialist (who happens to be very good) which was nice to hear as there is 500 litres of it and filling the system would take days. Not to mention cost.
New boiler put in, everything works perfectly at the moment. Guarantee from manufacturer (of which this specialist is certified) granted, 5 years.
No extra cost, done as part of installing the hardware.

There is a filter installed on return, just before the boiler, so not to allow contaminants into heat exchanger. Serviced annually.
 
I agree this thread could go somewhere a bit less nautical, but anyway, I have just flushed a 12 year old system and to be perfectly honest, the use of power flush systems are a bit of a sledgehammer to crack a nut (and make plumbers money!)

Basically, if you have cold spots in your radiators, the problem can be sourced to two culprits.
If they are cold at the top you have air in your system and simply need bleeding, however if they are cold at the bottom there is sludge in your system; you need to flush it.

If you have a closed system, they easiest way to do this is to fix a hose to you lowest radiator outlet (should have a hose connector) and put that into a drain.
Then isolate the boiler heating flow and return cocks, connect the filling loop to one of the heating loop pipes and turn on the water supply. Its a good idea to close all of the radiator valves and opening them on one radiator at a time to flush.

It's a bit difficult to explain and to cover everyone's system setup but basically it certainly isn't rocket science, there's plenty of videos on yotube that could help.
 
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