Correct way to plumb in rads.

[Keithsurf62]

Hi
I'm having a new boiler after 16 years and wanting to address a problem with the instalation of 2 tall rads. I'm not a plumber and did this DIY fit in my younger years to cut costs when we moved in and I'm pretty sure I did it wrong as the internet wasn't as useful back then.
The rads have always taken ages to warm up and rarely get too hot to touch unless the heating has been on constant for a few hours so I guess I plumbed them wrong.
I plumbed them so that each ones in and out feeds branch off the main flow rather than the flow going through the rads as part of the main flow. Which is right, branch off or run through. As water will usually travel in the path of least resistance I'm assuming thats why not as much goes up into the rads from the T as its easier to just go straight on? Many thanks for any answers.

 

[cross thread]

they should be connected from the heating flow and into the return if you have a Two pipe system ,if it’s a one pipe you are never going to get good performance from tall rads.

 

[ETAF]

did you or have balanced the system ?

 

[Keithsurf62]

I think it's a 1 pipe system so maybe that's why then. As far as I know I balanced it best I could. Thanks

 

[ETAF]

I think it's a 1 pipe system

you did say

I plumbed them so that each ones in and out feeds branch off the main flow rather than the flow going through the rads as part of the main flow.

is that just 1 pipe you used - or a feed and return separate pipe ?

 

[Keithsurf62]

In all honesty I don't really know. The rads are fitted in a loop so is that a feed and return?

 

[Justin Passing]

YOu need to know if it's 1 pipe or 2 pipe. If it's 1 pipe all the rads are in series, and probably have a pipe underneath connecting flow and return.
If they don't have that pipe, turning one off will stop the lot.
1 pipe is pretty hopeless, and TRVs and modern boilers aren't designed for it. Modern TRVs are too restrictive.

Usually it's not all that much plumbing to convert from one pipe to two, if you draw the plan of the house and where the pipes are..

With 2 pipe, all the rads would be in parallel, like bulbs in a car.

It's only the shaded bit which s new pipe, if you get me. You change fittings... You can order the rads how you like to make it short, for your layout.

 

[Keithsurf62]

Thanks for the diagram. From what I remember when I was under the floor I think I've done it as the first one so will look at changing the pipework as suggested, makes sense. Just need to widen the hatch in the floor as either it's shrunk or I've grown in 15 years....

 

[foxhole]

Some rads are designed for both vertical and horizontal use , these have internal knock outs that need removing for vertical use .