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I need to add 3 rads to an existing system. There is an existing rad with accessible pipe work close by. The 3 rads are all close to each other. Do I simply pipe a loop from one of the existing rads pipe through to the other 3 rads and tee back into the other existing feed? Bit like how I would extend a electrical loop?
Or should I be doing something different? Google brings back adding a single rad not multiple. I’ve read flow and return aren’t an issue with newer rads
It is potentially as simple as that, however adding 3 rads will mean you should only T into a 22mm pipe, cutting into an existing 15mm pipe that is all ready feeding at least 1 rad will drastically reduce the flow of you add another 3 into it.
Rads should be in parallel rather than in series to use your circuit analogy.
"Designer" rads quite often have a specific flow and return due to the baffles in them.
Its easy to work out which existing rad pipe is flow. Just pop the heating on and sit by the rad to see which pipe gets hot first.
So if In parallel how should I pipe it? Im not running it all back to the boiler…. That would be massively disruptive, and I’m sure the rads don’t all go back direct to the boiler.
Not sure on the diameter of the existing rads pipes. I think 15mm. Renovations have removed 3 rads but all the pipe work has been removed by the builders months back
Pipe it with the flow on the existing rad to the flow on the new rads and return on the existing rad to return on the new rads.
Same as putting a bulb in parallel with an existing bulb
Don't know how your system is designed, and this is a simplified take, but really the should be a 22mm loop (or even 28mm, depends how big your house is and how many radiators you have) running round the house and then each radiator takes a 10/12/15mm flow and return from this loop. You can use this calculator to figure out how big the pipe should be for your needs. DeltaT is 20K for a condensing boiler, average water speed needs to be >0.3m/s to avoid sludge buildup but probably limited below 1m/s to prevent a noisy system. Unless your radiators are VERY small I wouldn't advise trying to run 4 from a single 15mm loop. It would be worth pulling a few floorboards to see if you can find the 22/28mm loop.
And after you've added the radiators you'll need to balance the system again, starting from the one furthest away from the boiler and working your way back.
OK thanks for pointing me in the right direction. After a little research I understand what I need to do...so I'll have to work back from the closet rad to find the flow and return loop and then t into that, with the 3 rads all running back to it they are all within 3m of each other so should be straight forward.
in fact I do recall seeing some bloody big pipes under the floor and assumed they were for the old boiler.
I'm only confident in working with push fit, any issues with using speedfit on a CH system? used on hot and cold.
"designing" a system is a bit grand. we've bought some rads we like the look off, and I've gone bigger than i think we will need with the view incan always turn them down if the extension gets too hot....my simple brain says there was 5 rads we removed so I'm just putting 5 back (2 already piped by plumber who let me down)
so if the pipe I'm thinking is indeed the 28mm heating circuit, any issues with using a speedfit 28 to 22mm reducer tees to create a new small 22mm loop that I then tee the 3 new rads to in 15?
(all speedfit)
and whilst I've got you here....how do you remove a magna clean that just won't budge. tried with as much force as I'm will too at the point the pipework starts to move I'm not putting any more force in! does it need cutting out and replacing?
I’m only confident in working with push fit, any issues with using speedfit on a CH system? used on hot and cold.
No but make sure the pipes you are joining on to are clean. Copper onto speedfit et al also has a greater chance of damaging the o ring so make sure the cut is not sharp push on nice and square and give a squirt of PTFE lube
Yeah, I wouldn't be using a hacksaw to cut copper pipe ready for a speedfit connection. You can get a proper pipeslice from Plumb Center/Wolseley/Willie Wilson/whatever they're called at the moment.
how do you remove a magna clean that just won’t budge?
Two big spanners method? If you're going to cut it out anyway I'd have a go at removing it with spanners first. Grasp both spanner handles in one hand and just squeeze them together rather than going one hand on each spanner. You'd be suprised just how strong the human grip is.
work back from the closet rad to find the flow and return loop and then t into that
That's what I'd do.
If you do end up replacing the filter be mindful that the first 1 metre of pipework from the boiler <span style="text-decoration: underline;">must</span> be copper and not barrier pipe, so if your filter is closer than that I'd be trying very hard to get it off with spanners. I also wouldn't be all that happy connecting the filter with barrier pipe either, but that's maybe just cos I was taught to use copper throughout.
thanks, the filter is right under the boiler so will need to be piped in copper. another reason I'm not keen on messing with it. I'll have a look to see if I have spanners big enough. I take it it isn't reverse thread or something dumb like that?
I have a 22 and 15 pipeslice, they are great tools. Will need a 28 though.
jobs getting expensive 🙂