Flushing a sealed system

[basmic]

Right, I'll start with what I know:
Boiler: Halstead Quattro Gold
Downstairs: Small rad in bathroom close to boiler, and a large double in the living room
Upstairs: Large and medium single radiators, serving the two bedrooms

I can hear odd little 'popping' noises and crackling noises from the boiler, more-so when the heating is on a high temperature (50% on knob, on the front of boiler).

I did ask the plumber who does the landlord checks, and he said it would cost in the region of £200-300 to flush the system - I'm assuming this would solve the problem.

Anyway, after a friend did his (open (?)) system and recommended me this cleaning stuff, I had a look on a DIY site (beginning with S) - and for nearly £8 for each of the bottles that I need I'm tempted to give it a try myself. He reported that his system was almost 50% more efficient after flushing.

From what I've read the prcoess is as follows:

1. Turn boiler off (using switch at front of boiler)
2. Open bleed valves on both radiators upstairs, and catch any water
3. Open bleed valves on both radiators downstairs, and catch most of the remaining water
4. Undo the bolt (opposite side of the normal control valves) at the bottom of the radiator, and flush off any excess water
5. Close valves on one radiator downstairs
6. Add cleaning soloution to open radiator downstairs, and put back together leaving the bleed valve open
7. Slowly fill the system until water comes out of radiator
8. Stop filling, close bleed valve and continue to fill until upstairs radiators are full - then closing bleed valves on those radiators
9. Allow cleaner to run through system for specified time (1-2 weeks, with normal use)
10. Flush three times, using steps described above
11. Add inhibitor, and voila!

Feel free to correct me where I am going wrong - I am a TOTAL newbie to this sort of DIY, and don't want to blow the house up...(lol?)

Thanks...particulary for being patient with me. [/list][/b]

 

[EliteHeat]

Your plumber was talking about a power flush which is different to what you are suggesting. If you add an item to your list called "attach hose and open drain-off" your method might work. If it doesn't it's only cost you eight quid.

The good news is though that it is almost impossible to accidentally blow your house up by doing anything that you mention

 

[kier]

i use fernox f2 superconcentrate noise silencer.£16.00.
much easyier to dose your system,dose via a radiator or via filling loop hose useing a standard sealant applicator gun. £1.00.
its a lot quicker and little chance of spilling water.
see www.fernox.com
click products then repair products then click on super concentrated silencer f2.
good luck.

 

[JohnD]

If you haven't already got at least one drain-off at the lowest point of your system, fit at least one of these to your downstairs radiator.

If the pipes to the downstairs rads come down from the ceiling, you need one on each downstairs radiator.

If you have a sealed system, surprisingly little water will come out when you unscrew and remove your old radiator valve, provided you don't remove more than one at the time and the filling loop is closed.