Adding A radiator....Using the flow circuit only

[TheBigMatt]

Hi Softus,
Thanks for your patience.

Let me start again,

I have a regular CH system driven by a combi boiler.

As i understand it, there are pumped flow & return circuits from/to the boiler,each radiator is connected once to the flow circuit (rad valve) and once to the return circuit (lockshield valve).

Assuming i have that correct...

What i want to do is to break into the Flow to a given radiator (not the main flow circuit),& insert another rad. The water from this new rad will continue on into the old rad and then back to the boiler as before.
I.E if i turn off the new rad, the old rad goes cold as well.

I would call this being connected in series, instead of being added in the "normal" way. Is this OK??

I believe that you suggested i could do a similar thing BUT instead of breaking the flow to the original rad use 2 x "T" pieces and so achieve a Parallel connection.
I.E if i turn of the new rad, the old rad still gets hot.

What i was worried about was how the water would circulate around the new rad, as it would effectively have 2 flow connections and no return.

All of this is because i cannot easily access the return circuits as they are all under the floor, and it is impracital to lift the flooring/floorboards at the moment.

The flow circuit for this particular rad happens to be (historically) in the loft, making it an easy job to break into it. The New rad and the Old rad will be in the same room (bathroom)

If i knew how to upload a diagram i would do so if it would help.

Regards Matt

 

[Softus]

Hi TheBig

As i understand it, there are pumped flow & return circuits from/to the boiler,each radiator is connected once to the flow circuit (rad valve) and once to the return circuit (lockshield valve).

At the risk of sounding picky, I wouldn't say that there are two circuits, but a pair of pipes corming just one circuit (much like the concept of a domestic electrical ring final circuit). By convention, the pipe carrying water from the boiler is called the "flow", and the one carrying water into the boiler is called the "return". Correspondingly, the water arriving at a rad does so on a pipe that is teed off from the flow, and leaves it on a pipe that is teed into the return.

What i want to do is to break into the Flow to a given radiator (not the main flow circuit),& insert another rad. The water from this new rad will continue on into the old rad and then back to the boiler as before.
I.E if i turn off the new rad, the old rad goes cold as well.

I'm with you.

I would call this being connected in series, instead of being added in the "normal" way. Is this OK?

It makes sense.

I believe that you suggested i could do a similar thing BUT instead of breaking the flow to the original rad use 2 x "T" pieces and so achieve a Parallel connection.
I.E if i turn of the new rad, the old rad still gets hot.

Yes.

What i was worried about was how the water would circulate around the new rad, as it would effectively have 2 flow connections and no return.

Yes, I can see that you're worried, but try not to be. This a microcosm of a pipe topology known as a "single pipe system", where there's only one pipe instead of a pair, viz:

All of this is because i cannot easily access the return circuits as they are all under the floor, and it is impracital to lift the flooring/floorboards at the moment.

The flow circuit for this particular rad happens to be (historically) in the loft, making it an easy job to break into it. The New rad and the Old rad will be in the same room (bathroom)

If you find that a single pipe arrangement for the new rad doesn't work, you can easily turn it into your original arrangement by either (a) replacing the tees with elbows, or (b) inserting a closed valve into the pipe that 'bypasses' the new rad.

Does this make sense?

 

[Agile]

I still think that you two are talking at cross purposes!

Softus thinks you have a single pipe system as evidenced by his diagram.

The OP is not sure what he has got but I have no reason to think that its still a standard two pipe system.

A nice Softus diagram of a standard two pipe system should enable the Op to decide which he has.

I dont know because I have not been there but still think he is describing a two pipe ( with some difficulty ).

Tony

 

[Softus]

I still think that you two are talking at cross purposes!

Oh give me strength.

Softus thinks you have a single pipe system as evidenced by his diagram.

No. I. Don't.

FFS, the diagram is the proposed topology.

The OP is not sure what he has got but I have no reason to think that its still a standard two pipe system.

A nice Softus diagram of a standard two pipe system should enable the Op to decide which he has.

I dont know because I have not been there but still think he is describing a two pipe ( with some difficulty ).

You've had too much Easter Monday red wine Agile. The OP knows what he has. I know what the OP has. Heck, even the Pope knows what the OP has.