Central sealed system question

jgallcash

I live in a development of 54 flats and as new builds we have had a number of challenges with boilers. Long story short.... pressure has dropped in the systems at various speeds and because people haven't topped up the system manually some of the boilers have given up the ghost.

I was shown how to manually top up my boiler and have to do this maybe once every 3 months to increase the pressure to 2 bar.

I have been told that in sealed systems there is some chemical present and it is not just merely water running through the radiators and pipes. Also told that topping up the system manually with water will eventually make the system perform poorly or worse damage it.

Is there any truth in any of these comments? If so what is the chemical that is present? Should I be doing something to ensure the lifespan of the boiler?:beer:

roger196

When the boiler is cold, the pressure should be 1.5 bar ( some models will be 1.0 bar you need to check the instructions which can be obtained from the manufacurers website). If the pressure falls below 0.8 bar ( some models 0.5 bar), the boiler will cease to function until the pressure is topped up. This is normally done by a filling loop (a flexible braided pipe) which should be disconneted after topping up to prevent the possibility of the CH water contaminating the drinking water. A few models use a detachable key, check the instructions again.
If the pressure is still dropping, there is either a water leak somewhere or the automatic bleed valve in the boiler (assuming there is one)is taking a long time to remove the air from first filling.
You need to add a lot of water before the inhibitor (usually Sentinel X-100 or other makes) is seriously diluted. You could ask the gas bloke to test the water for sufficient inhibitor at the annual service or use one of these kits www.bes.co.uk part no 18812(Fernox) or part no 7583 (Sentinel)

gas4you

What boilers are fitted in your flats?

jgallcash

Made by 'Ideal' can get more specific info tonight if it would help.

EssexFitters

Hi reading this post and noticed jgallcash asked how to fill the system... im guessing you are using the filler loop to fill the 'sealed system' - to fill a sealed system with inhibitor you either need to purchase a pressure filling bottle that you attach to the filler loop or drain system and inject inhibitor into a radiator. AND yes it is very important for your pipe work, rads and boiler that you don't allow the inhibitor to run low. You will get a good 3-4 years with out it but will notice leeks along the way. Where do you live? you will be charged around £120 from a plumber for a job like this and that's including the inhibitor which will cost him around £25