Radiator Flush

[Icemaiden23]

Have just had our boiler repaired (again) and been informed that the radiators will need flushed as they are full of brown sludge. The house is only 5 years old and the repair man said that there had never been any inhibitor added. We have had the boiler repaired around 10 times now, which is a lot in itself, and this has never been mentioned before. Just looking for some advice as the quote for the powerflush is over £700. We have had an annual service plan with the same company for 4 years. Should the housebuilders have ensured that the system had inhibitor in the first place? Any advice/help would be greatly appreciated. Many thanks.

[johntywino]

I,d change the company!!!I can't see how your system could be full of sludge after only 5 years If you want to check it out turn off a radiator, put a bowl under and carefully undo the rad from the pipe a little way and see how much black "Sludge" comes out!.Go to B&Q and get some rust inhibitor and put it in the system....Incidentally the rads are on a sealed system and don't keep taking im fresh water,so there shouldn't be reason for sludge....

[The Builder]

Yes, there should have been an inhibitor added when the system was installed.
But, after only 5 years, it really can't be that bad that it needs a powerflush.

Somewhere around the lowest point of the system there will be a drain valve. A little spouty thing, probably attached to a radiator valve.
Push a hosepipe over it and throw the other end of the hose out into the garden.
Switch off the boiler at the wall.
Open the valve and drain down.
Assuming it's a combi boiler, open up the filling loop to the boiler to let in fresh water. Eventually the water should run clean(ish).

[The Builder]

Oh yes ........ as Johnty said .......... do the final re-fill with inhibitor in it. The pack will tell you how.

[johnny37]

Im not an expert but there are a couple of questions come to mind. Firstly, I believe the first sign of sludge will be that the bottom of the rads are cold while the top is hot. The other thing is why was your boiler repaired 10 times? You may have had a right to a replacement because the system was not fit for purpose (including no inhibitor). Your rights do not stop after 12 months. Under consumer protection a boiler should last more than 5 years. Check your NHBC guarantee or contact the NHBC. There may be a problem in that accepting the repair and paying for it you have invalidated any possile claim.

[marden40]

you say the house is only 5 years old, are you the first occupants in the house and how long was the house stood empty before it was occupied.....this could have major implications on the condition of the system and should have been checked out before you moved in......the best advice is exactly as "the Builder " has said....the drain off will be on a rad close to an outside door so its convenient for the hose to drain the system to the outside...this type of flush should be adequate for a system of this age....but I would do the flush a couple of times, leaving a few days between, then follow the inhibitor instructions on the second flush

[buildersmate]

No point even looking anywhere near the NHBC warranty.
The warranty regarding 'technical' type components is 2 years - it is only the structural warranty where 10 years is relevant.
Do as The Builder suggests.

[Icemaiden23]

Thanks for all your help. The house was completed end of September and we moved in beginning November so it wasn't empty for long. Also the radiators are cold at the bottom so obviously does need flushed. Will try what's been suggested,

[Icemaiden23]

p.s. most of the repairs have involved lack of pressure, code that comes up. Should the company (national) that services/repairs have looked into this before now? The last service was only a month ago (albeit the engineer said that if there were still problems he would come back and strip the boiler). Before this repair, three days ago, I was topping up the system continually and if the boiler did cut out I was managing to get it started again - eventually! Sorry to go on, but... just a bit annoyed to think that this could have been dealt with before it got so bad that they want so much to fix!! Hopefully my DIY, as suggested by yourselves, will work!

[johnny37]

I still think she should go for a replacement on the boiler, through the small claims court if necessary. 10 repairs in the first five years? Contact the original installers.

[The Builder]

Frequent topping up and lack of pressure most often indicates that the pressure vessel needs recharging (bicycle pump from Halfords ....... vessels usually have a "schrader" valve, the same as a car tyre.)
If not, then maybe the vessel diaphragm is ruptured.......... pressure rises, blows out of the safety valve ........ losing water and pressure.