Flushing on commissioning

[LA3222]

Right, what's the crack with this flushing malarkey? All the instructions for UVC and ASHP go on about it to clear crud, debris etc. 

 

Does anyone do it? Will a flush through with mains pressure water do?

[Nickfromwales]

8 hours ago, LA3222 said:

Right, what's the crack with this flushing malarkey? All the instructions for UVC and ASHP go on about it to clear crud, debris etc. 

 

Does anyone do it? Will a flush through with mains pressure water do?

A wise man I once chatted this over with, sterilises the primary pipework before introducing the anti-freeze / inhibitor mix into the system. IIRC he uses a wheelie bin with a submersible pump and a load of Milton tablets. He says this gives maximum longevity to glycol etc and he has a lot more letters after his name than I do so I tend to listen when he speaks. How many people here have done that is unknown. 

[LA3222]

1 hour ago, Nickfromwales said:

A wise man I once chatted this over with, sterilises the primary pipework before introducing the anti-freeze / inhibitor mix into the system. IIRC he uses a wheelie bin with a submersible pump and a load of Milton tablets. He says this gives maximum longevity to glycol etc and he has a lot more letters after his name than I do so I tend to listen when he speaks. How many people here have done that is unknown. 

That sounds like a lot of effort. You raise something I hadn't considered though, what is a reasonable effective life span of the antifreeze mix? 

[Nickfromwales]

1 hour ago, LA3222 said:

That sounds like a lot of effort. You raise something I hadn't considered though, what is a reasonable effective life span of the antifreeze mix? 

Some say 5-7 years, others say indefinite. Best to ask the manufacturer of the one your considering using. 
Milton technique is more for GSHP I think, where the longevity of the glycol is a serious cost consideration, plus the glycol cannot be dumped into the collector as one ‘slug’ as it will congeal and not function / protect plus it will cause serious problems with circulation.

[Bonner]

Sterilising the system will kill bacteria and other organisms but it won’t necessarily remove any debris. That is a bit specialised IMO, a good flush through with mains water will clean the system quite adequately. Used to be needed more in full copper pipe systems due to swarf and flux, which is corrosive. Modern systems should be a lot cleaner.

[LA3222]

On 07/09/2021 at 16:04, Bonner said:

Sterilising the system will kill bacteria and other organisms but it won’t necessarily remove any debris. That is a bit specialised IMO, a good flush through with mains water will clean the system quite adequately. Used to be needed more in full copper pipe systems due to swarf and flux, which is corrosive. Modern systems should be a lot cleaner.

That is pretty much as I thought. Flushing needs some proper kit, all i intend on doing is a rinse through at mains pressure. Cylinder came pre plumbed so most of the plumbing is compression/push fit, not much in the way of soldered joints.