Central heating - power flush required ?

[brightspark]

i did all; my own radiators copper pipework and valves no plastic crap . just got my mate to fit the boiler i did the flue through the roof . didnt cost me a lot and got the boiler guarantee and paperwork as well;

 

[gaz1]

we got the grant fitting even the signing person was annoyed at the fitters as the system wasnt done right, then we added more rads to the system as its big enough to do so

then ive upgraded some of the rads to better ones

no treatment in my system and the water is clear though i do flush and drain every few years and the water is still clear inside

the worst system ive come across is fireback copper boilers and pipework and one system that the hot water tank had burst upon inside its so gunked up badly it takes some heating ive flushed it with a full day of flushing and its still poor but its been working for the last few years but owner buys other stuff when they should do whats needed and then moans as i wont touch it in winter ( cold months)

 

[JOEPRO]

My rads are all working perfectly, no sludge in the middle. Clear water.

Thermal camera shows this very well


Rad behind curtain looks "cool" -

 

[knighty]

why not fit the filter now and does it with system cleaner / flush with water a few times before the change over?

 

[angellonewolf]

when they done my boiler 10 year ago id allready changed half the rads in the system when he come to fit the system he said did you want to flush the system but it will be more paid work if it casuses a leak or i can run a cleaner through the system and flush out a few times with water pressure did turn off every rad and went round and turned on the rads in sequance and every couple years i put a bottle of inhibator in the mag clean and he said the system when he done the last time its all ways just got a smuge of black over the magnet thats it and even the water is clean when you run some out

i think as long as you top up the inhibator often that makes a major dfifferance and i dont think they do that as part of the service they will test the water but top up is chargeable as cost them extra ?

 

[Morrisman]

Many years ago we had a system that clunked and klunked and grumbled every time it was turned on. New water pump twice, done by British Gas Homecare. Eventually the guy refused to work on it any more, said it needed a power flush and a load of pipework cutting out as it was lined with rust. £800++ he quoted, 20 years ago.

I went to see a mate who owns a big plumbers shop in Stafford, he wasn’t there but when I told my sad story to the guy at the counter, hoping for a cheaper quote, he reached behind him and gave me a bottle of some chemical. He said put that in and let it work a few days, all your noises will go away. And they did.

I had to add another bottle a couple of years later, but £20 suited me better that £800++. Fernox springs to mind, for the name of the stuff.

 

[armalites]

When I did a load of work on my heating I bought one of these

https://www.thoroughflush.co.uk/product/thoroughflush/

I fitted dedicated connection points near the boiler and set them up with valves so I could flush the boiler by isolating the filter return and the flow to the HW and CH or isolate the boiler and flush the system. It works incredibly well, you connect into the system on flow and return, connect mains pressure water and a drain. The valve allows you to instantly reverse the flow so you can dislodge deposits. You can then isolate radiators and leave one open to flush. Whenever I check the Magnaclean now there is only ever slight deposit.
The kit has pretty much everything you could ever need and comes in a nice kit bag.

 

[Morris]

The kit has pretty much everything you could ever need and comes in a nice kit bag.

Anything that comes in a nice bag must be ok

 

[armalites]

Anything that comes in a nice bag must be ok

amazingly it all fits back in the bag with zero issues.

 

[prepman]

I intend replacing ALL the house radiators and fitting a new combi boiler (gas aspect will be done by a qualified Gas Safe person). A Fernox TF1 filter will be fitted.
That means all that will be left of the old system will be the pipework.
Is a full power flush needed or would just mains pressure flush be sufficient ?
Cheers

One question is it headtank or expansion (sealed) system. Former I'd replace, latter I'd flush. Ferrox fllter?

 

[CompoSimmonite]

One question is it headtank or expansion (sealed) system. Former I'd replace, latter I'd flush. Ferrox fllter?

Current is a old type boiler with header tank but intend changing to combi.
On reflection cost of a proper power flush, even doing so myself with hired equipment, isn't cheap so decision made to put such a cost towards ALL new copper pipework.

 

[brightspark]

just washed my magnacleen on the heating today as this thread reminded me it hasnt been done for over a year new boiler has been in over ten years thought it was only about 8

 

[Mark 5]

I intend replacing ALL the house radiators and fitting a new combi boiler (gas aspect will be done by a qualified Gas Safe person). A Fernox TF1 filter will be fitted.
That means all that will be left of the old system will be the pipework.
Is a full power flush needed or would just mains pressure flush be sufficient ?
Cheers

Current is a old type boiler with header tank but intend changing to combi.
On reflection cost of a proper power flush, even doing so myself with hired equipment, isn't cheap so decision made to put such a cost towards ALL new copper pipework.

In no particular order but to answer a question, no in your case, a power flush is not required although flushing will be.

Assuming your existing set up is working it would do no harm to throw some CH cleaner in the header tank and let it circulate for a few days, you can flush if you want, in your case I see no point as system will be drained, tank/header tank will be removed/disconnected, the exercise is to simply clean any kept pipework internally.

Converting from a standard boiler to a Combi is straight forward but can be disruptive, carpet/boards up, that type of thing.

While conversion is relatively straightforward there are somethings requiring consideration, some or all may apply to your existing/new installation.

Brand of Combi, Rads' is your choice, all installers have their favourites but any decent installer should be able to install any combi of your choice without whistles or words of drama as is how your new system is to be controlled/zoned.

Don't get caught out on sales spiel as to to 5-8-10 year warranties, most will never apply unless you jump through an awful lot hoops.

If possible and the correct size, try to keep old copper pipe work in play, with some caveats.

Old copper pipe of yesterday year is, imo, far superior to the crap copper of the last 20 years, the caveat, like any copper pipework old copper work does have/can develop pinhole leaks.

Old CH systems/pipework will invariably have lead soldered joins, nowadays it's lead free and while that's a good thing, there is still a fair amount of misinformation as to lead or lead free, most installers will use lead free, resolves all concerns, the point I'm making is if you can use old copper, it doesn't have to be removed because of leaded joins.

Yesterday year it was common practise to install 15mm pipework everywhere, rule of thumb with combi installations, 22mm to rads' with 15mm tails, 15mm to all hot/cold outlets.

You may have to upsize gas supply from your side of the gas meter, this will depend on your existing gas appliances or future needs, this needs to be considered with any new installation, due to extra costs/hassle, is often overlooked or ignored altogether, your installer should be able to do the calcs.

Running a bath off a combi has always been taxing although doable, shower outlets and combis in most cases, no issues.

Make sure any quotes/estimates you receive include you receiving a gas safety certificate and in writing.

That's my quids worth.

 

[hunter27]

When fitting combi boilers I often fitted the 15mm filling loop on the return and a drain valve on the flow directly under the boiler, then by turning off either boiler valve under the boiler you could reverse flush the system turning off all the rad valves and flushing each rad one at a time.
Several boilers have a built in filling loops now but they are usually very thin bore and restrict the flow a lot but that doesn't stop anyone fitting an old style loop as well.
When plumbing a boiler it only takes a couple of minutes extra.

 

[gaz1]

When fitting combi boilers I often fitted the 15mm filling loop on the return and a drain valve on the flow directly under the boiler, then by turning off either boiler valve under the boiler you could reverse flush the system turning off all the rad valves and flushing each rad one at a time.
Several boilers have a built in filling loops now but they are usually very thin bore and restrict the flow a lot but that doesn't stop anyone fitting an old style loop as well.
When plumbing a boiler it only takes a couple of minutes extra.

i dont like using the boilers valves as they are known to fail so with my own system i have proper stop valves

comes in handy if you ever have to refit another boiler just shut the valves disconnect the pipes change the boiler and refit then its just fill up the boiler and turn the valves back on again so no draining of the central heating system but plumbers dont fit them for profit for themselves

but like you i prefer an external filling loop than the boilers also fills quicker as well