Hot flush or power flush

[FergBut46]

Hi - I need to upgrade my old combi boiler to a new condensing combi. Existing Worcester Bosch 24 cdi installed before 2002 (date unknown). Rads may be older than that (house built 1986). Would you always recommend a powerflush to clean the system? One guy has advised that a hot flush is sufficient and that a powerflush isn't what it's cracked up to be. I'm dubious, as I've seen others mention that not having a powerflush invalidates the guarantee.

Also, I've assumed I'll need new 22mm pipework from gas supply to boiler (about 9 metres apart)..... same guy seemed to dispute that this was necessary. I have strong reason to believe pipework isn't already 22mm, as neighbours in identical house have had new pipework run along outside wall.

Any advice on powerflush vs hot flush and pipework would be much appreciated. Ta!

 

[muggles]

Hot flushes are for girls, powerflushes are for heating systems...

 

[Twin Dad]

I'll soon be looking for a new boiler on a central heating system installed in 1987.

Be interested to know what the difference between the two are?

 

[Madrab]

most reputable manufacturers will insist on a powerflush to validate their warranty for a boiler replacement.
A hot flush, apart from the girlie variety that muggles mentioned is when the system has cleaner added, the boiler run up until the system is hot and then drained and flushed out.
A power flush is where a powerful pump is used to flow cleaning agents and water back and forward through the whole CH system along with other activities - vibrating rads to loosen material etc - to ensure the system is as clean as it can be before installing a new boiler. New boilers can be susceptible to blockages if this isn't done correctly due to narrow waterways through heat exchangers etc.

 

[Cgas]

Definitely worth getting it power flushed, yes it's added cost on an already expensive job, but you will regret it further down the line when manifolds etc start blocking cus all the existing crap in the system has started to manoover itself into your nice 2 year old boiler causing you a lot of hassle and will end up paying to get it power flushed further down the line cus the manufacturers refuse to replace parts when they take a water sample and you have no proof it's been flushed. Be careful as some people call it a powercleanse this is just another name for filling/chemicals/draining a system to attempt to clean it.

Edit: most boilers need 22mm supply....... However let him quote you not to upgrade it and make sure it's a fixed quote and you'll get it done for free - serves him right!!!! Worth a try.

 

[gazdaz36]

It depends on how good the person power flushing is. A bad flush is worse than no flush at all because all they will do is loosen and dislodge the crud, then leave it to float around your system until it ends up blocking up your boiler

 

[Bunnyman]

As said it depends how well it's done and how dirty the systems are? I have fitted many hundreds of boilers but mine are all Combi swaps.. I never power flush (muck moving) . I hot an cold flush an can honestly say I've never had any problems. Power flushing has its place for older and dirty systems but some just pay lip service, move the muck an Fook up the new boiler 6 months down the line...

 

[Madrab]

The other tip I would give, once the flush is done, is to have a magnet filter installed into your system. It is yet another expense but so is repairing a blocked boiler. This allows any muck that is still in the system to be filtered out before it hits the boiler.

 

[FergBut46]

The other tip I would give, once the flush is done, is to have a magnet filter installed into your system. It is yet another expense but so is repairing a blocked boiler. This allows any muck that is still in the system to be filtered out before it hits the boiler.

The most thorough quote so far includes power flush, magnet filter, system shock arrestor, scale reducer etc. They're a local company with good rep, but pricier. They also confirmed that I'd need new 22mm pipework. Beginning to think it's worth paying a premium for peace of mind.

Thanks - appreciate all the comments.

 

[Madrab]

Yup, it's a rare beast that provides the best overall system at the cheapest price. It can be good economics to spend that little bit more to ensure everything is up to scratch.