powerflush

[ambrosia]

when power flushing a heating system with a combi boiler, if you dont isolate the boiler are you risking damaging the diverter valve, plate heat exchanger etc

I've been doing powerflushes without isolating the boiler because i thought powerflushing the heat exchanger would be a good thing,
have i been lucky so far not to have caused myself more problems, or is this how the majority of you guys do it

 

[michael c]

technically you should isolate to prevent any sludge being pushed into the boiler. I have seen mentions of people powerflushing the boiler/heat exchanger independently of the rest of the system.
Personally i would isolate the boiler and flush the rest of the system clean. Once you are confident it is clean then open the valves and flush the boiler. Most Mi's do state to isolate boiler during flushing so just be aware you would be liable if the flush created any faults.

 

[ambrosia]

thanks Michael,
so its the slush problem rather than fragile components

 

[dave1]

Had a job this week where a power flush caused the main heat exchange to block on a flexicom. I'd recommend isolating the boiler.

 

[michael c]

as far as i am aware ambrosia. Never heard of a heat exchanger being damaged as generally you dont flush much higher than the operating limits of the boiler if at all.

 

[Roger Welton]

Generally do it with boiler, though if during a swap with the old boiler as I like to get the system good and hot to make the chemicals more active. I do us a magnacleanse in line though so hopefully most of the gunk is removed before it gets back to the boiler..

 

[lame plumber]

plate hex liable to totally block if you shove contents of a rad thro it by mistake, shouldnt happens but all that sludge and the owner turns on a hot tap!

 

[Roger Welton]

plate hex liable to totally block if you shove contents of a rad thro it by mistake, shouldnt happens but all that sludge and the owner turns on a hot tap!

Shut cold feed under boiler

 

[lame plumber]

Shut cold feed under boiler

theres always that, but having told her not to touch any hw taps etc whilst flushing off she went!!!!!

 

[FD Powerflow]

Best thing you can do is get a powerflushing filter. Realistically you want the boiler on so that you can get heat in, heat = faster chemical reaction, think washing machine, doing the dishes or good old school days with a bunsen burner. Powerflushing filter will stop magnetite from banging back through HX.