Flushing radiators with sentinel x400 - any tips?

Penny_Farthing_2

HiMy DH is going to try to flush our heating system with Sentinel X400 tomorrow morning. He's not the best at DIY and I've got a nasty feeling about all of this. Please does anyone have experience/ tips to offer?Thanks

EliteHeat

What is his exact plan on how to achieve this?

Penny_Farthing_2

Umm. Don't know and he's taken our 3 and 2 friends swimming so I can't ask at the mo. Do I take it from your question that it's A COMPLICATED JOB?

EliteHeat

No, I just thought from your complete lack of confidence in his abilities that it was worth asking what his plan was.

Penny_Farthing_2

Aah, now I love my DH to bits and he's very good at very many things, but as the sloping shelves and 'extra' drill holes in the wall above every curtain rail will testify, DIY is not his best skill - though he is keen. My aim is to offer gentle support and encouragement - not to rip the poor man to shreds. BUT we can't afford to get a pro in and I will need some heating this winter! Should I start by asking him what his plan is in the hope that will steer him into having one?

malamute

Penny, Elite Heat sounds like someone who knows all about this type of job .

I carried out this job 2 years ago (system had been in use for just over 22 years).
I drained the system and topped up with fresh water and ran for 24 hours and drained.
I carried out above 3 times and every draining the water got cleaner.
Now i put the cleaner in and ran the system for 7 days and drained followed by a flush. Then it was time for the inhibitor and the system has run perfectly for the last 2 years.

The way i did it required entry to the loft and putting the chemicals into the system that way (remember a foot through the ceiling does not come cheap), you can buy a kit that allows you to put the chemical's directly into one of the radiators.

Penny_Farthing_2

Thanks Malamute. We have a combi boiler and I don't think there's anything in the loft. If you drain a system, how do you know when it's full when you refill it?

malamute

Every radiator has a bleed screw make sure they are all closed, with water supply on, you work from the ground floor up and open each screw individually until the water starts to drip / run slowly out then close the screw. You do this to all the radiators separately until the whole system is done.
Draining is the opposite with the water isolated work from upstairs down with the drain open outside the house.
There is all sorts of advice and guides on the Internet use Google with "Chemical Cleaning central heating system" as your search.


Example

http://www.diyfixit.co.uk/diy/centralheating/_centralheating_index/_centralheating_index.html
has every thing you need to know see index.

EliteHeat

You have a combi? That’s a bit of a surprise and there is good news and bad news associated with it.

The good news is that it is a simple procedure with no feet through the loft ceiling involved. The bad news is that your sealed system should not require flushing at all.

I don’t want to sound condescending but it’s back to basics for a bit. In an open-vented system (with a header tank up in the loft) the system has an unlimited amount of oxygen available to it. As everyone knows, oxygen is the catalyst for corrosion and these systems can get pretty clogged up. A sealed system is the reverse, it has a finite amount of oxygen in it and when this is depleted – via corrosion – it is not replaced.

Therefore, the question you should be asking yourself now is “why does this need doing at all?”

Anyway, the practicalities of the procedure are easy. Just do these:-

• Run system to maximum temperature on heating
• Attach a hose to your drain-off and open it.
• When the hose stops running, open the rad air vents starting from the top
• When this is done and the hose stops running the system is empty(ish)
• Close the drain-off and rad air vents
• Disconnect the cold water side of the filling loop
• Pour your X400 into the open filling loop – slowly
• Pressurise to a constant 1 bar while someone else bleeds the rads
• Run the heating as much as possible for about a week and then flush
• Add X100 as a final step before re-pressurising
• All done

That is it. Good luck. Very little to go wrong!

Canucklehead

Hi

Was the system sealed from new ?

Corgi Guy.

Penny_Farthing_2

Thanks both. Have discussed DH's plan over dinner and Elite Heat's step by step guide sounds the job. Thanks for your help but I think there'll be questions! Will get DH in to have a read in a minute. Our boiler is one of the first Worcester combi's so has been going for years. We plan to replace as soon as we can afford it. My kitchen fitter thought he was doing me a favour by draining the system 3 or 4 days in advance of the plumber coming to move a rad. I think that's what caused sludge to settle in the system so a couple of rads don't get very hot. We got help with that on here and closed each rad down until the cold ones were forced to work. It worked the once but I couldn't be doing it all the time so we thought a flush would help.We'll also check out your helpful link Malamut. Signing off to swap to laptop.