To power flush, or not to power flush (small property)

[lookbadgers]

I have a small 2 bed terrace and I'm planning to replace the old heat only boiler with a combi. My plumber has suggested for the price of the power flush I could replace the 5 radiators, because the sludge normally accumulates there.

However after looking through the forums here the general consensus seems to be you need the power flush but this was for a much large property 4 or 5 beds, firstly would the same apply to my 2 bed?

Are there any cheaper alternatives if I replace the radiators then a power flush?

Is a power flush only required by the combi boilers? Should heat only boilers also have a power flush or will the manufacturer still give you that 5 year guarantee even if the system if full with sludge?

Thanks for your time

 

[Howsie]

Welcome along.

Dose it with some system cleaner, mains flush, change the rads. Job done.

 

[lookbadgers]

Thank you.

I'm currently trying to justify the extra cost of the combi boiler, since half of the difference between the combi and the heat only is the powerflush or radiator replacement. Could a manufacturer of a heat only refuse the guarantee if there is lots of sludge, or does the heat only not have such small internal pipes, so therefore it is never a issue?

The extra space from a combi is an advantage but the extra cost means I would have to sacrifice something else in my house. So the smaller I can make the perceived difference to myself the better really.

 

[Masood]

You're going to be hard pushed to quantify the amount if sludge to be able to judge whether the larger waterways in the heat-only boiler will cope without a powerflush. Howsie's solution would be the ideal compromise, and prolong the life of your new boiler, as well as not giving the manufacturer any ammunition to wriggle out of warranty work.

 

[Gary71]

The quality of the water dictates the level of flushing required.


Theres nothing to wriggle out of, the system is either clean or it isn't, identifying the impact of contaminated system water isn't rocket science, it is what it is and the customer is the one who picks up the tab a couple of years down the road.


Flushing with mains can work well but it's dependent on the level of contamination and if its not left right then your looking at no warranty or in some cases a new boiler.

i think you'll have to trust your installer on his opinion of your system water.

 

[AWheating]

the required flush is the one most suitable for your system. as we cant see your system you will need to take the advise of your gas safe heating engineer on board more than a stranger on the internet. If the system has a small amount of sludge then a chemical flush with the mains should be enough, if its heavy sludge then the only solution is a power flush or replace it all.

 

[PowerFlusher2]

Careful reading of any manufacturers instructions will show that it says 'the system must be flushed'. It doesn't say 'powerflushed' so chemical or mains pressure flushing would qualify as complying with manufacturers instructions.

 

[lookbadgers]

Thank you for your replies it has given me some more confidence in what the engineer is suggesting. I assume it's easy enough for them to carry out a chemical test to find out if the mains flush and new radiators are enough?

 

[Gary71]

Careful reading of any manufacturers instructions will show that it says 'the system must be flushed'. It doesn't say 'powerflushed' so chemical or mains pressure flushing would qualify as complying with manufacturers instructions.

All a manufacture requires is a clean system, it's up to the experience of the installer to decide what method, leaving anything in the system that impacts on the boiler still can effect the warranty.

 

[Gary71]

Thank you for your replies it has given me some more confidence in what the engineer is suggesting. I assume it's easy enough for them to carry out a chemical test to find out if the mains flush and new radiators are enough?

There are tests but most installers go by the look of a water sample or monitor the water coming out of the drain down hose.

 

[AWheating]

Careful reading of any manufacturers instructions will show that it says 'the system must be flushed'. It doesn't say 'powerflushed' so chemical or mains pressure flushing would qualify as complying with manufacturers instructions.

most instructions will say something like the system needs flushing to the current british standard BS whatever. This standard allows 3 types from memory, gravity, mains and powerflush. Your choice is based on the systems needs/condition, but at the end of whatever flush you do the system must be very clean. Manufacturers will refuse warranty claims due to sludge, you are the engineer, you need to use your engineering judgement to decide whats meets the requirements.

dont make assumptions that because the MI does not use the word powerflush you dont need to carry one out.

 

[stevetheplumber]

if the existing system is open vented i would say you definitely need a powerflush