new boiler and powerflush

[spammed]

Finally decided to get a new boiler fitted - going for an external combi boiler. Old boiler/pipework was fitted in 2005.

Plumber attended today to power flush prior to fitting the boiler tomorrow. He said the water wasn't too bad, a greyish color. He was here for around 90 mins and as far as I can tell didn't use any chemicals... just pumped clean water around the system. Anyway, tonight I swapped one of the radiators and the water coming out of it was very dark/almost black...

I am a bit worried about the new boiler being fitted if there is still dark water in the system. Is it worth disconnecting all the rads and manually flushing them out in the garden or would that be OTT? Thanks.

 

[Mottie]

I think that when doing a 'proper' powerflush, you are supposed to go round doing one rad at a time and use some kind of vibrating thumper thingy on the rad being flushed to loosen the crud inside. You'd be better off taking all the rads outside and giving them a good flush through and shake up.

 

[ianmcd]

that is not a power flush, a powerflush involves a machine and takes half a day to a full day to do properly

 

[spammed]

Thanks. He is a local guy I know quite well and I know he wont charge me much. He said that power flushing didn't remove everything and the new magnetic filter will help. We are also going to remove all the rads in the morning and manually flush them outside. Do you think that will be good enough?

 

[Mottie]

I got a ton of crap out of my rads that way. Take them outside, half fill with a hose, tip them back and forth, upside down etc. empty, rinse, repeat until you can get no more black stuff out.

 

[FiremanT]

I got a ton of crap out of my rads that way. Take them outside, half fill with a hose, tip them back and forth, upside down etc. empty, rinse, repeat until you can get no more black stuff out.

The reason that PFing gets a bad name is because of poor execution. As Ian points out it is at least a half day - I use to allow all day and expect to complete in 6 hours. Very boring watching water go in circles and disappear down a drain, though. It gets more exciting if you lose concentration and the pump is on the landing carpet

You have gone to all this work to clean the crap out of the rads, and you have pointed out that it takes some effort.

Why do we then imagine that the pipework, valves and pump are not all full of the same Shiite, and will not be redistributed on next use?

 

[Mottie]

If you're not having a full and proper powerflush, you can only do what you can do. I know the rest of the system can still contain some crap but I would imagine that the majority of the silt would be in the rads (and the header tank if it's a vented system) and that adding some system cleaner may shift a fair bit of the rest?

After I cleaned my rads, I ran some cleaner through for a few days and drained it several times before my boiler was fitted and then inhibitor and a mag filter was added. Been very clean in the 4+ years that was done.

 

[FiremanT]

If you're not having a full and proper powerflush, you can only do what you can do. I know the rest of the system can still contain some crap but I would imagine that the majority of the silt would be in the rads (and the header tank if it's a vented system) and that adding some system cleaner may shift a fair bit of the rest?

After I cleaned my rads, I ran some cleaner through for a few days and drained it several times before my boiler was fitted and then inhibitor and a mag filter was added. Been very clean in the 4+ years that was done.

The point is that when fitting a new boiler you sent REQUIRED to have a CLEAN system. It is not REQUIRED to do a PF, but whatever you do do, it must result in a clean system- and excuses such as time or expense will not cut it when a warranty engineer tests tge water.

Traditionally, people moan about combi’s performing badly a couple of years after installation, often the water going hot and cold.

I think it is likely that a lot of problems occur due to poor prep work and fitting a boiler in 2 hours