difference between sealed and open vented/draining a sealed

[beaumontnz]

hi everyone,

how do you tell what kind of system you have?

I believe if it is open vented there is an extra exspansion tank in the loft, but what is there if it is a sealed or combi system?

Is there any way of telling without venturing up into the roofspace?

I am venturing into the property world,but this is something I do not know about.

i have also read that you must consult a professional before draining a sealed system,but also have heard it is not that much different than a n open one.Do you just do as normal(is there a tank in the loft)?, and open up the drain valve and let it run?

any advice appreciated.

 

[muggles]

As you have said, if you've got an open vented system then you will have a feed and expansion cistern in the loft. If it's a sealed system then the boiler or system will have a pressure gauge, there will be a metal braided flexible filling loop and a hot water cylinder in the house somewhere. If it's a combi boiler, then the boiler will fire when you switch a hot tap on, and shut down when you switch it off. There will be 5-7 pipes going to the boiler, and there will be no hot water cylinder.

You can drain a sealed system yourself, just open the drain valve as you say. The tricky bit is getting fresh inhibitor into the system (essential) when you come to refill it.

 

[beaumontnz]

thank you for your reply.
however i am slightly confused when you refer to a sealed system,you say' there will be a hot water cylinder somewhere', then later on state 'there will be no hot water cylinder if its a sealed system'.

don't think i'm being pedantic, i'm no plumber!

 

[Goldspoon]

First things first...

If you have water tank/s in the loft (or high in house) then you have a vented system (tanks are usually black plastic or galvanised steel) and have a valve in that lets water into the tank when water is used in the house. These tanks will have a 22mm copper pipe, open on the end, that points into the tank (called a vent pipe).