Best way to install new flow and return but add rads at staggered times?

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Hi

I’m installing a new combi boiler with new flow and return as part of an extension, and this will feed the existing flow and return in the existing house, and then go on to feed new radiators in the extension.

I’m doing it all in copper with regular end feed fittings.

My question is, what is the best way to install as much of the pipe work now, but leave it so that I can easily add the new rads later (each time I do up a new room, I’ll want the rad to go live, so there’s about five different times I’ll need to add a rad).

I was going to put the 22/22/15 tees in now, but then how do I leave the 15 branch?

If I put the 15mm pipe in to the rad location and just cap it off, then when I fill and pressurise the system, there will be a load of dead end air in there that’s gonna maybe sit there or worse start to slowly work it’s way out and my auto air vent / deaerator will release it and I’m going to be fighting with pressure drops all the time.

Alternatively i add a short stub to the tee and then cap that off but then I’ve got to unsolder the stub out the tee which I’d prefer not to do.. (unless it’s the only way)

Or I could fit full bore valves to every 15mm branch of the tees but I don’t like the idea of having ten valves hidden away forever that could cause problems down the line.

The way I’ve designed the system I can fairly easily drain down the new flow and return to mess with the tees later. But surely there must be a way of just blocking off a branch without de-soldering later on?

Any other ideas?

Thanks!
 
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Bring the 15mm branches to each rads position and cap them with compression fittings, which you could loosen to release trapped air if need be.
 
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Bring the 15mm branches to each rads position and cap them with compression fittings, which you could loosen to release trapped air if need be.
Oooh that’s a good idea, so as I fill the system I can slacken them off till they weep, so I know the air has shifted? Is this the go to system for new installs then?
 
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Very common with extensions to take pipework to a particular point and cap ,ball ofix valves, push fit stopends ,compression stopends....whatever is on the van !!
 
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Silk purse out of sow's ear?
You're right to avoid using isolating valves, especially if you're thinking of using those cheap 1/4 turn valves...the heating water will quickly disperse the lubricant from the 'o' ring under the screwdriver slot, and the first time you have to rely on one it'll tear that 'o' ring and leak.

I assume you'll be installing under a suspended wooden floor.
Have you considered extending the (22mm?) flow and return pipework as you go, adding enough F&R pipework to reach the next room each time. This way you have a fighting chance of ending up with a neat installation, not peppered with excess joins?
Another way might be to work backwards from the 'last' room towards the existing F&R pipes, and joining into the wet system right at the end. Don't discount using electric heaters in the meantime...the emotional cost of making an unsatisfactory joint and the reparatory work that follows far exceeds the cost of a few weeks' electricity. ('er indoors will remember the leaking joint ( your leaking joint ) long after the inconvenience of switching on-off portable heaters is forgotten.

MM
 
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Silk purse out of sow's ear?
You're right to avoid using isolating valves, especially if you're thinking of using those cheap 1/4 turn valves...the heating water will quickly disperse the lubricant from the 'o' ring under the screwdriver slot, and the first time you have to rely on one it'll tear that 'o' ring and leak.

I assume you'll be installing under a suspended wooden floor.
Have you considered extending the (22mm?) flow and return pipework as you go, adding enough F&R pipework to reach the next room each time. This way you have a fighting chance of ending up with a neat installation, not peppered with excess joins?
Another way might be to work backwards from the 'last' room towards the existing F&R pipes, and joining into the wet system right at the end. Don't discount using electric heaters in the meantime...the emotional cost of making an unsatisfactory joint and the reparatory work that follows far exceeds the cost of a few weeks' electricity. ('er indoors will remember the leaking joint ( your leaking joint ) long after the inconvenience of switching on-off portable heaters is forgotten.

MM
Ha funny, but wouldn’t adding f+r as I go still result in needing to cap off a branch of a tee? Although come to think of it I’d only need to cap one off each instead of five off each so it’s a really good idea! Cheers mate
 
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Guess it all depends on whether the final positions are already known or not. If you know exactly where everything will go then no reason not to run the backbone and feeds to where they need to go to get yourself ahead. If you don't know then no point.

Any system I use like that I just put rad valves on the ends to allow them to be bled and the system tested.
 
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Guess it all depends on whether the final positions are already known or not. If you know exactly where everything will go then no reason not to run the backbone and feeds to where they need to go to get yourself ahead. If you don't know then no point.

Any system I use like that I just put rad valves on the ends to allow them to be bled and the system tested.
Oooh rad valves on the ends, that’s a good idea - thanks!
 
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Just use copper olives and don't rack them right up, nice and hand tight then half a turn with an adjustable and they'll twist off again when taking them off. Be gently and you can re-use the olives with a turn of (gas) tape.
 
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Just use copper olives and don't rack them right up, nice and hand tight then half a turn with an adjustable and they'll twist off again when taking them off. Be gently and you can re-use the olives with a turn of (gas) tape.
Thanks a lot for the advice. I’ve read your comments a lot. I know you love your gas tape. Cheers mate.
 

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