Replacing stopcock, which size

[1animal1]

Hi, I am looking to change my stopcock to a 22mm version. I am currently getting everything ready for my unvented system and figured I'd get this done whilst I've got the floor up downstairs re piping the bottom central heating ring.

The plan is to run the pipe into the adjacent garage which runs parallel with the hallway, so that I can line off to the necessary 15mm pipes going upstairs, and run to where the unvented will be situated at the back of the garage.

I presume the blue pipe in the picture is a standard 22mm and I'll need and compression stopcock?

Thanks

 

[Scott_D]

Did you fit the one with all the PTFE on?

 

[1animal1]

Thanks Shaun. The unvented was going to be situated in the back corner of the garage, so I imagine it'd be similar footprint? This seems to be a halfway house.... What's the efficiency like compared to an average unvented? And is there a contingency should the combi stop working for hot water?

Yep, that's mine with the PTFE Scott. It's entirely hidden so didn't need to be neat

 

[ShaunCorbs]

yes same foot print and the same if not better but no, no elec immersion

 

[1animal1]

Apart from the lack of emersion and annual service, what's the downside compared to unvented?

Imagine the cost will be similar given the outlay for the unit (I had budgeted £3000-£3500 for the unvented).

And can I use with 2x CH rings with a potential underfloor add on..... And nest

 

[ShaunCorbs]

other than less stored water non

speak to your installer but should be

and yes

 

[1animal1]

Cheers Shaun, seems like you've given me a real credible alternative here.... Thanks.

I think the next step is to get this pressure checked first and foremost....

From reading, it seems I may still need this 22mm feed?

 

[ShaunCorbs]

Cheers Shaun, seems like you've given me a real credible alternative here.. Thanks.

I think the next step is to get this pressure checked first and foremost..

From reading, it seems I may still need this 22mm feed?

its best so just come straight out of the 20mm alk with a 20-22mm stop tap

 

[1animal1]

Excellent.... I'll try and source one. Should I bother my plumber now for just a pressure check given my 26/30 LPM readings?

Also... Should I direct all 15mm feeds to the various colds to where the boiler sits for post boiler balancing, or am I ok spurring off the 22 on the way to the boiler... Guessing the first suggestion so as not to reduce pressure to the new boiler

 

[ShaunCorbs]

I would to check, no harm in double checking also get the pressure static (no outlets open) and dynamic (one outlet open)

And yes 22mm straight to the boiler

 

[king of pipes]

Combi boilers have improved alot another option is this one from Alpha innovations i recently went on a training day and was impressed with its output they had a working model there supplying 4 outlets at the same time , someone on here will shoot me down but personally i would give one of these units serious consideration , you can have a immersion heater added in the model with seperate storage and if it could be installed central to you property it would save on water useage.cheers kop

 

[1animal1]

Opened a right can of worms here

Thanks kop. I'll certainly have a look at that.... My thinking is now cost orientated. Can I get two digital power showers going through a boiler with minimal heat change, integrate 2 CH rings with a nest on each, with availability to add one wet floor ring... The contingency of an immersion would be a bonus given the almost inevitable circumstance of the boiler going down at some point.

Worth pointing out that one power shower has a 3 metre minimal drop on 32mm pipework (couldn't get it any lower without major work due to stack location). So the flow doesn't need to be 30 LPM (obvious extreme). Also the climb to the furthest shower is probably 10 metres into the loft where it will connect to a digital mixer

The other power shower will be over a bath with what will be a 40mm waste if needed

Do any of these requirements rule any particular system out?

 

[1animal1]

For this joint, the 20mm/22mm stops are none existent as expected. Think I'm going to have to go up with a Philmac coupler, into a 22mm bend, then run a tap after that....

I love a challenge

 

[ShaunCorbs]

Plasson 7110 Reducing Coupler 20mm x 25mm | Travis Perkins

Plasson Adaptors for Copper Pipe 22mm x 25mm | Travis Perkins

You could do it that way and then out in 22mm

 

[1animal1]

I could, but with the space I have, it would be a struggle.... With the Philmac I can get the piece to fit on the pipe, the coupler being 132mm tall (only question is how much mdpe I need to fit into it), 22mm bend, then the tap after that... Otherwise I'll have to site the tap further away into the garage. Least amount of connections and all that....

The bend is inevitable I'm afraid

Or 20mm mdpe stopcock, 20mm bend onto the Philmac... How do these plastic stop cocks fair for longevity? Compared to say a peglar brass 22mm?

 

[1animal1]

I've just checked and my waste is 40mm to the shower...so I should be a good for a decent flow rate