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Jonty · Joined: 26 May 2008 Posts: 7 Location: Lincolnshire, UK

I have a Rayburn cooker/boiler driving 11 radiators and domestic hot water. The heating side is hopelessly innefficient with only the top 6 inches of each radiator getting hot. The system is clearly sludged up and I would like to clean it out including the pipework and boiler.
Any advice on the best way to do this and any potential pitfalls would be very gratefully received. Oil prices being what they are I feel like I'm just throwing money away!
Cheers.

th4rn · Joined: 04 Jun 2008 Posts: 3 Location: uk

either get a professional to powerflush your radiators or turn off the mains water and take the rads of the wall one by one and clear them out with clean water

Jonty · Joined: 26 May 2008 Posts: 7 Location: Lincolnshire, UK

I am going to take the rads off anyway-I've done this before one by one. I was more concerned with flushing out the pipework and the boiler after the rads are removed.
Any thoughts anyone?

thescruff · Moderator Joined: 03 May 2003 Posts: 4755 Location: Bath

please remember the cooker needs 24-48 hours to cool down before you drain the water.

AlanE · Posted: Fri Jun 06, 2008 9:34 am Post subject:

Hire a powerflushing machine!

Dose the system with cleaner and run for 2 to 3 weeks then hire a flushing machine to flush the system out. Take around a day but everything, rads and pipes will be a lot cleaner than simply taking off wall and flushing.

Alternanatly dose system as above, make up adapters to convert pump couplings to accept hose and flush with mains pressure through system one rad at a time. Not as effective as machine.

Get a rubber hammer to hit each rad as you are flushing it whatever way you do it.

Jonty · Joined: 26 May 2008 Posts: 7 Location: Lincolnshire, UK

Thanks for those thoughts. I was warned against using a powerflusher given that half the system is over 25 years old and the other half is in a big extension we built 10 years ago. I was told that powerflushing may reveal weaknesses in some of the older pipework and joints. My main concern is making sure that the Rayburn boiler gets cleaned out as it's retaining too much heat. If I don't use a powerflusher how can I achieve this? I don't want to undo the heavy duty pipework to the boiler as this will seriously reveal my own shortcomings at plumbing!
Meant to add!
If I use a powerflusher can I do this without removing the radiators?

Yellowman · Joined: 03 Jan 2008 Posts: 83 Location: Sussex

You can get a pump head adaptor for the flushing machine. basically you remove the head of the pump and this screws in its place.

Withy the machine you can actually circulate and clean the boiler without acually having to touch the connections.

I have powerflushed a few older systems and never had problems to be honest.

thescruff · Moderator Joined: 03 May 2003 Posts: 4755 Location: Bath

Before we go too far it would be handy to know a little bit more about the cooker model etc.

Most Rayburn type cookers have a limited output for heating and hot water, I suggest you are way over that limit without more information.

AlanE · Posted: Sat Jun 07, 2008 5:59 am Post subject:

That is a good point Scruff. Just reread the original post and there are 11 rads.

Try turning off say half of them and what happens? If they now get hot vertually all over then it's not sludge.

Have they ever all worked properly? What are the approx sizes, & types, of radiators.

Jonty · Joined: 26 May 2008 Posts: 7 Location: Lincolnshire, UK

Thanks all for the input. Rayburn is a 760k model designed to feed minimum 12 ordinary sized domestic rads and the hot water. System worked fine for about four years after installation then has gone steadily downhill. The pump is over-capacity and was renewed four years ago. I have, over the last five years, sporadically taken radiators off and cleaned them out, turning upside-down and banging with a soft mallet whilst flushing with a high-pressure hosepipe, putting back on and bleeding copiously.They then work fine for a while until the gunge circulates round the system again. We have a mixture of older (steel) radiators about 26/27 years old and some more lightweight radiators about 10/12 years old. Would I be better to replace all the older part of the sysytem.
Still would like to know how to flush out the pipework and boiler!
Thanks.

AlanE · Posted: Sun Jun 08, 2008 7:41 pm Post subject:

Jonty · Joined: 26 May 2008 Posts: 7 Location: Lincolnshire, UK

Many thanks for all those comments-very gratefully received.
I've decided to go down the powerflushing route. Nothing ventured etc!

Yellowman · Joined: 03 Jan 2008 Posts: 83 Location: Sussex

Good decision.