Converting from an vented system to sealed system

[MilSki]

I've recently renewed my boiler and installed a vented system. Can I convert is into a sealed system without changing the boiler itself. And what items would I need to have changed?

 

[Slugbabydotcom]

Why ask about changing the boiler when you have just renewed it? d:-S
Are you sure your terminology is correct?
What is the make and model of the boiler that you have just renewed?

 

[MilSki]

2 years ago i replaced my old boiler with a vaillant ecotec 428 boiler. The CH and Hot water system is an open vented one. I don't want to change the boiler, I only want to change the system to a sealed system and get rid of the header tanks in the loft. I not sure if I can do this without changing the boiler too..

Your advice is appreciated.

 

[45yearsagasman]

Read the MI's and that should tell you all you need to know about your boiler and sealed systems.I am almost certain you will be ok.

 

[xr4x4]

Beware of old joins springing leaks at the extra pressure.

I have seen many old joins that have fell apart when moved.

 

[Slugbabydotcom]

The information you require is on and around page 16 here
You will only lose the small F&E tank that feeds the CH system unless you get a combi fitted or have your hot water cylinder replaced with an unvented one by suitably qualified persons of course.

 

[MilSki]

Thanks for all the advice..

 

[mogget]

Another tip with these boilers is to have the pump set on maximum, if you haven't already. I have the (related) Vaillant 418 and it's very finicky about having plenty of water flow through it. It doesn't modulate properly if there isn't enough flow (boiler cuts out or goes to minimum flame).

Mine is also a sealed system converted from vented and one poorly made joint did pop. Fortunately it was a drip rather than a deluge and was in an easy-to-fix location.

Sealed system components you would need are expansion vessel, filling loop, pressure gauge and IMPORTANTLY pressure relief valve with pipe safely positioned outside. Not ending above the patio door like my neighbour's