D.I.Y Power Flushing central heating system

[happychap]

Looking for some advice on how to flush my central heating system without damaging any of the internal parts of the boiler. The boiler is a Worcester green star system fitted in 2007. I've seen on You tube a method by which after taking one of the ground floor radiators off, and isolating all the radiators but the one that is to be flushed and fitting a hose pipe to to outlet and another to the inlet connectors. This then allows you to flush each radiator in tern, my query is about isolating the boiler and not having the water being forced through the boiler to get to each radiator. I hope that makes sense.

[Rickyy]

You need to use a powerflushing machine. Running mains pressure water will remove gunk in the pipes and some in the rads, but nowhere near as effective as a proper flushing machine.

You can hire them from most tool hire companies.

Alternatively, you could remove the rads and blast them out with the hose pipe, but obviously the pipework and boiler will still need cleaning.

[roofer]

As Ricky suggests. Before I plumbed the AGA in, I took all the rads off, made up loops between the fittings, and put mains pressure through for an hour. It only took the girlie an afternoon to mop up where one of the connections came adrift

All rads had bungs etc removed and flushed out and turned and flushed again, remarkable how much sludge is created in them, which fekking stinks ( she said )

[happychap]

Thanks for the reply's chaps. The option of taking the radiators off might be the best way to do this, will give a bit more thought.

[Rickyy]

happychap said:

Thanks for the reply's chaps. The option of taking the radiators off might be the best way to do this, will give a bit more thought.

Won't harm to bung some cleaner in the system for a week or two first, this should mobilise any crud in the system and make it easier to flush out.

Consider fitting a magnetic filter to the boiler return also.

[henrycrun]

I've done this. Choose the ground floor radiator to be removed adjacent to a door or window for the inlet (garden) hose and exit hose.

Make up some fittings with an inline tap so you can start, flush until the exit water is clear and stop.
Mains water pressure unlikely to harm the boiler.

[Foppo]

My radiators are now thirty five years old.Unless I have been very lucky never used a power flush.

What I did do every four to five years drained the system and took every radiator in the house off.Then emptied the radiators in the garden.Put all the radiators back and added fresh Fernox in the system.

We used to have a small Glow worm boiler which was replaced after about twenty eight years.The radiators we have are the old Myson radiators.We now have a Combi Boiler.Still have the copper microbore pipes which have proven to be ok.One radiator upstairs has a Thermostate on it but in the winter I warm the whole house.I don't turn any radiators off.

Just my experience with central heating.

[happychap]

henrycrun said:

I've done this. Choose the ground floor radiator to be removed adjacent to a door or window for the inlet (garden) hose and exit hose.

Make up some fittings with an inline tap so you can start, flush until the exit water is clear and stop.
Mains water pressure unlikely to harm the boiler.

I've identified the radiator in the kitchen that enables me to run the outlet pipe to the outside drain that has the outside tap next to it so that follows your advice. I'm looking for confirmation that using this method will not damage the internals of the boiler as the water is forces through to flush each radiator. Thanks again for the comments.

[Rickyy]

happychap said:

henrycrun said:

I've done this. Choose the ground floor radiator to be removed adjacent to a door or window for the inlet (garden) hose and exit hose.

Make up some fittings with an inline tap so you can start, flush until the exit water is clear and stop.
Mains water pressure unlikely to harm the boiler.

I've identified the radiator in the kitchen that enables me to run the outlet pipe to the outside drain that has the outside tap next to it so that follows your advice. I'm looking for confirmation that using this method will not damage the internals of the boiler as the water is forces through to flush each radiator. Thanks again for the comments.

That method will not be very effective. Water takes the path of least resistance, so it will just run around the outside of the rads and miss most of the gunk in the bottom. You'll also lose most of the mains water force through friction in the pipework.

That's why powerflush units have a massive pump on them, to keep a high flow rate through the rads.

Taking them off the wall and cleaning them with a hose pipe is far more effective, you can then run mains water through afterwards to purge the pipework out afterwards.

[dazwalsh]

I just remove the bleed valve of the radiator near back door and connect a hosepipe from that into the drain, I open up the filling loop and flush the radiators one at a time, a few soft blows of a rubber mallet to the bottom centre of each rad whilst its been flushed breaks up more of the crud. Once all running clear I put fresh water and inhibitor in and jobs a good in.

I add system cleaner a few days before hand and for a few hours before I whack up the heating to full.

I do this every 2 years to each of my rentals. Out of 26 boilers I rarely get called out to them.

I've seen some 4 figure quotes for powerflushing which is frankly madness, a few hours and a few quid for cleaner and inhibitor is all it takes.

I understand a powerflush is more powerful and effective but if you get THAT much crud in your system there is something wrong.

[Mick50NCD]

More often than not commercial heating systems incorporate valves when the system is fitted when new to be able to maintain the system but very few domestic heating system have these valves.
If there are valves fitted so that the heating system can be isolated from the boiler and tees/valves which allow the fitting of hoses to allow flushing the heating circuit only. Every radiator is isolated bar one radiator deemed to be the 'starting' radiator and mains water pressure is then allowed to flow through the radiator that is turned on. It is imperative to make sure the drain hose valve is open fully and one radiator is on and all others in the heating circuit is off when the water runs clear through the 'open' radiator the next radiator must be turned fully on before the clean radiator is shut off. The procedure is done until all all the radiators are flushed.
The boiler can also be flushed singularly if valves are in situe to allow the process but of course the safety bylaws state that no valve shall be fitted into the flow pipe that would prevent the escape of pressure within the heating system.
If the heating system is warm / hot when the process of flushing occurs it will be seen that as the radiators cool clean water replaces the dirty water in a very large percentage of water within the radiator circuit.
After the initial flush without chemical the system can then be used for the correct time as per the chemical manufacturers instructions & the the process as above can be redone. The water quality
then observed to see that there are then no solids or chemical present in the water that is left in the system.
In heating systems the quality of the circulating water,the saying 'cleanliness is next to godliness' is very sensible if not essential.......