Quick Plumming Question

Apip99

Morning all.

How can I tell if I have a sealed heating stystem or just your run of the mill gravity circulation?

I'm in the process of building an extension and have mounted the new radiator, and run all the new pipe work (the push and click joints are amazing).

I was hoping to be able to connect to the rad in the kitchen, but upon reading, if its a sealed system, I should get a trade plummer to do it. But surly it can't be that hard.

Non of my rads have a valve to connect a hose to, in order to drain the system.

Help please.

Thanks,

Pip

10-10-20

If you have a header tank (second water tank in the attic) or if the boiler has a pressure gauge which reads above 1 bar, or if there is a fill valve near/under the boiler which is normally off.

I'd also guess that a very high pressure discharge from a rad vent would be a clue also!

Apip99

Thanks for reply.

There is no pressure gauge on the boiler, and there are 2 tanks upstairs. Althought they are both the same?? Apart from one has a pipe. I'm guessing this is the Open Safty Vent Pipe. I've attached a picture

So my system is not sealed. Happy days. Now where on earth would the the valve be to conect a hose to drain. Not on any of the rads,, near the boiler, or under sink!!!

10-10-20

Sorry - I should have been clearer. I should have said two tanks other than the large coffin tanks pictured. You would usually have a small 2ft x 2ft tank, but you don't appear to have.
It could still be pressurised! Best wait for somebody else to come on to clarify further.

JamesM

Look for a large red (usually) cylinder close to the boiler - sometimes other colours, in other locations. If it is there - you have a sealed system. If not, there must be another smaller tank in the attic.
Jim.

TKK

You won't definitely have another tank for a non-pressurised system. I have a non-pressurised heating system and only one tank in the attic. The feed to the heating is taken, through a non-return valve off the feed to the cylinder.

10-10-20

And, the pressure vessel is often integrated into the backplate of the boiler these days... so you can't rely on that either!

JamesM

TKK wrote: »

You won't definitely have another tank for a non-pressurised system. I have a non-pressurised heating system and only one tank in the attic. The feed to the heating is taken, through a non-return valve off the feed to the cylinder.

I am pretty sure that yours is a sealed system. If you have a non return valve how does the water expand ? Maybe you just haven't spotted the pressure vessel
Jim.

Apip99

Its a sealed system.

And thanks for all the replies.

I have a plummer freind calling tomorrow night to hook it up.

Cheers guys N gals

Pip

TKK

The non-return valve is on the feed into the heating system to keep it topped up (there is also a valve which can be turned off with a screwdriver just before the non-return valve).

There is also an expansion pipe which feeds back up over the main tank.

Thinking about this I'm not so sure it is a good setup. Isn't the water in the heating system usually dirty? If so will that not contaminate my main water tank if there is a problem and the expansion pipe is called upon to do it's job?

2 stroke

If its a sealed system there is no expansion pipe from heating system expansion takes place in presure vessel. Just one from top of hot water cylinder. and sometimes in an airfilled dead end pipe.

JamesM

TKK, As 2 Stroke (and yourself) says, there should not be an expansion pipe from the heating system feeding over the main tank. Are you sure that that pipe is not from the ordinary water system in the hot water cylinder. If it is from the cylinder, it will branch off from the pipe coming out of the top centre of the cylinder (that's the correct way). If it is from the heating system, it will branch off the pipe from the boiler to the top connection of the coil going into the side of the cylinder (that is not good).
If it is the first, that's fine, but you still need to find out where your heating expansion is going. If it is the 2nd, I wouldn't want to be doing my teeth in that water :eek:
Jim.

TKK

You may be right on that JamesM. The more I think about it I believe that it is from the pipe at the top of the cylinder that the expansion I'm on about runs.

That leaves me questioning where the heating expansion goes/is. It's been a while since I looked at the heating system (given that it's been working ok since the time the non-return valve was seized and I couldn't get water in to resolve airlocked rads) so I may just be forgetting where it is. I'll have to stick the head into the hotpress this evening methinks.

I doubt, given the profile of the boiler (Vokera mynute 14e I think), that there is a pressure vessel built in and I know there is no space behind it as I'm currently doing some work on the other side of the stud wall that the boiler is mounted on.