How do I power flush with a dead/ no boiler in place?

[coldboiler]

My boiler has died. It stopped producing hot water and heating the radiators and now the pilot light won't come on.

I need to replace the boiler but also need to get the system power flushed first. How can I do this when the boiler will not come on at all? Some companies have said there must be hot water to perform a power flush and others have said it can be done with cold water but less effectively.

Is it possible to power flush once the old boiler has been removed but before the new one is in place? I don't want to send dirty water and sludge through a brand new boiler.

The manufacturers all insist on a power flush before a new boiler is fitted or they won't honor the guarantee.

All of this is very confusing and I am getting conflicting advice from all corners.

If anyone can advise I would be grateful. I am trying to comply with all the regulations but I don't see how I can get a proper power flush with cold water and I don't want to damage a new boiler.

Also, I need to remove the boiler in order to brick up the flue (the new boiler will exit further along the wall). Once removed can I create a loop to connect the boiler pipes and so rejoin the circuit so that I can flush through and still get tap water?

The old boiler is a Vailant Sine 18. I had a quote from a gas safe engineer to install a new boiler but then found out that he was not qualified to install a boiler spur and was not confident about bricking up the flue but may put a breeze block in. Hence I am trying to break the job done into its component parts to get the appropriately qualified people to do the various parts. I am also having problems getting someone to upgrade the gas pipe to 28mm as advised by Worcester Bosch.

 

[Ermintrude]

One person should be able to do all of this for you. Where are u located? Sounds like your having issues finding a tradesman, from your post you have found muppets.

It's rexcomened to flush with old boiler but not always practical. Some powerflushing equipment heats the water .

I wouldn't worry yourself too much. Post the job in looking for a plumber section on forum and you will get sorted. Don't use the bloke u have he sounds a complete twit!

What size boiler u fitting? How did wb advise you on gas pipe? This normally requires a site survey.... Can't really do it over phone. All they should have said is ensure pipes are correctly sized to deliver x!

 

[AWheating]

no you dont need to heat the water to powerflush. its like doing the washing up without hot water, it can be done but it takes longer with cold water because heat accelerates the cleaning process. You can use a heater with a powerflush machine to heat the water if you want to speed up the flush, it depends on the equipment your engineer has.

The other point is no manufacturer requires you to powerflush your heating system, what they require is you to flush the system to meet british standards. This could be a chemical flush, a chemical flush with cold mains, a chemical flush with a powerflush machine. Which one you require will depend on the condition of your existing system.

the gas pipework will need to be decided with a site visit and measure up. You could need 15mm - 35mm, who knows?

 

[jam1979]

pop ur power flush machine on your boiler flow and return once the boiler has been took out or the guy who changes your boiler will by rights flush it anyway