slow heating rads on 10mm

[perfect plumb]

Some people say that 10mm pipe is better for central heating systems but I find that it makes them very inefficient as the radiators take a very long time to fill up with such a narrow bore and therefore become less efficient as the boiler is still on full no matter how quick the rads are filling - any comments?
Are there any benefits to 10mm pipe in a central heating system other than fast fitting?
Thanks.

 

[newbie1]

in a word no
small bore slow flow and easily clogged
east to use small bore for tight spaces thats it

 

[stevetheplumber]

Some people say that 10mm pipe is better for central heating systems but I find that it makes them very inefficient as the radiators take a very long time to fill up with such a narrow bore and therefore become less efficient as the boiler is still on full no matter how quick the rads are filling - any comments?
Are there any benefits to 10mm pipe in a central heating system other than fast fitting?
Thanks.

i have to disagree ive noticed no difference in warm up times on microbore sytems .On a normal domestic system most of the radiators will be near closed on the return to achieve the desired temp drop across the radiator thus proving the pipe work is actually normally oversized
take a look inside any thermostatic valve and youll see the appeture is well under ten mil
the major benifit in new work is no joints below chipboard floors,pipework is installed through joists like cables at least 50 mm down so no nail damage and as you point out ease of fitting
micro bore got a bad name in the seventies due to sludge and pipe damage during building works with sealed sytems jetflushing and constant use of inhibitor sludge should not be a problem. Building sites are cleaner and plastic pipe more resilient to damage so this is no longer such a problem

 

[migoplumber]

agree with steve, and will add, if you look inside your 1/2 inch trv's you will see the bore is less than 8mm anyway!

 

[Plucky]

I've done a few new builds using 10mm plastic. Each floor has its own manifold and each rad has a seperate flow and return back to the manifold. Lots of pipe used but very good. Easy to balance and works extremely well. If you have a dodgy rad or leak somewhere in pipework you can isolate and leave rest of system up and running. Pipes go into a backbox with a special plate on the wall just behind the rad so first fixing is a piece of cake.

 

[Macca160670]

Hi

Could someone please help!

Currently got a heated towel rail in bathroom but due to it probably being too small and having a house with solid walls the heating may as well not be in on in that room as it is the same temp off on or.

Looking at having radiator 600x600 fitted the bathroom is only 6x6 foot so hoping this may do the trick.

Anyway two quotes for changing £150 and £125, had third quote today for £300 claiming that the pipe needs to be changed from 10mil to 15mil so floorboards will have to come up as well as tiled floor then whole system drained down etc etc.

Could you please advise??? I know I'm a women but come on is all that really necessary??? he claims that system can be not be effecient with 10 mil even though half the rads in the house only have 10 mil piping and I've not noticed any difference in heating with the smaller pipes?

 

[tamz]

10mm pipe will make no difference to how the rad works. Go with one of the other quotes.

 

[Billy Bob Bob]

as i always say nothing wrong with mini bore problems arise when plumbers expect to much out off it like overloading its btu carrying ability

 

[Macca160670]

Thank you for the response gents.

Can I assume that he was trying to make a bigger job out of it and that a 600x600 rad will be lower enough BTU for 10mil pipes.

Do you think that a radiator will do a better job than a small heated towel rail as todays plumber was sugguesting that the heated towel rail was sufficient and that the pipe was not capable of powering the towel rail?

 

[tamz]

Towel rails are really just towel warmers and are not really designed to heat the room although in well insulated houses they will. To get the same heat output as a 600 x 600 single rad the towel rail would need to be around 600 x 1750 if chrome or 600 x 1200 if white. (chrome gives of less heat)
If your house has uninsulated stone walls and high ceilings a 600 x 600 single will probably be too small. You will need around 800w.

 

[Macca160670]

Thanks Tamz.

Yes the current towel rail is chrome and approx 420 x 940 so it looks to be well unsized.

The rad I was considering was 600x600 double.. do you think this will be big enough?? The problem being that the bathroom is not very big so any bigger and you'll be burning your legs sitting on the loo

 

[plumbandplumber]

As a guestimate, your bathroom needs between 1500 to 1800 BTUs. A 6' X6' double rad gives out 3500 BTU. A 500mm X 400mm double rad will be closer to what you need. 10 mm microbore will easily heat this.

 

[Macca160670]

Thank you, that sounds good to me, I just don't want to go through the cost of changing it for the room to still be cold. I've already changed the window in their which did nothing to reduce the cold so the rad is the last resort!

 

[tamz]

A 600 high x 500 wide K2 would do it no problem. Stick a TRV on.

 

[Macca160670]

Thank you.

This website has really put my mind at rest so many thanks to everyone that responded,