Radiator - flow and return on same side?

R D S

unread,

Dec 12, 2019, 11:42:19 AM12/12/19

to

It would be advantageous if I could connect up a rad with the flow and
return on the same side (top and bottom).

I get that best case scenario it will take longer to heat up, will it
take a lot longer? Will it fully heat up all?

tabb...@gmail.com

unread,

Dec 12, 2019, 1:04:46 PM12/12/19

to

That'll work fine. Hot in at the top would maximise heating, better than the usual bottom entries. Conventional rads largely depend on gravity for internal circulation, you're helping that along here.

NT

harry

unread,

Dec 12, 2019, 1:14:52 PM12/12/19

to

On Thursday, 12 December 2019 16:42:19 UTC, R D S wrote:

Diagonal connections give the greatest heat output
Top and bottom on one side cuts heat output by around 25% for a roughly square radiator.
More if it's a long and low radiator.

Thomas Prufer

unread,

Dec 12, 2019, 1:38:54 PM12/12/19

to

Flow/return on the same side means derate by about 5%, i.e. hardly at all.

(unless it's a very long radiator, or you put the flow at the bottom and return
at the top...)

Thomas Prufer

Andy Burns

unread,

Dec 12, 2019, 5:06:41 PM12/12/19

to

R D S wrote:

> It would be advantageous if I could connect up a rad with the flow and
> return on the same side (top and bottom).

aka plumbed TBSE, obviously the flow has to be the top, return from the
bottom, or the water will short-circuit it.

> I get that best case scenario it will take longer to heat up, will it
> take a lot longer? Will it fully heat up all?

I have a radiator plumbed TBOE, rather than the usual BBOE, it warms up
fine.

Steve Walker

unread,

Dec 12, 2019, 7:26:04 PM12/12/19

to

Can you still get the valves that were designed to connect to one
connection only? The valve had both flow and return piped to it and the
return had a tube fitted that extended along the inside of the radiator,
forcing it to run from the far end.

A quick google has brought the type up:

https://www.plumbersforums.net/threads/flow-and-return-going-into-one-valve.46614/

SteveW

John

unread,

Dec 13, 2019, 11:55:09 AM12/13/19

to

Steve Walker <st...@walker-family.me.uk> wrote in
news:qsulqn$tuv$1...@dont-email.me:

> https://www.plumbersforums.net/threads/flow-and-return-going-into-one-v
> alve.46614/

Obsolete as a thermostatic version was never made + many plumbers didn't
understand the significance of the internal pipe - or broke it when
removing a radiator.

"Twinfast" I believe.

harry

unread,

Dec 13, 2019, 12:00:07 PM12/13/19

to

They were made by Yorkshire Copper and called "Biflow Valves".
Haven't seen them for years. They worked well so long as the internal pipe was fitted.
Googled but no results.

R D S

unread,

Dec 13, 2019, 12:03:12 PM12/13/19

to

On 13/12/2019 00:25, Steve Walker wrote:
>
> Can you still get the valves that were designed to connect to one
> connection only? The valve had both flow and return piped to it and the
> return had a tube fitted that extended along the inside of the radiator,
> forcing it to run from the far end.
>

I can't find one in the wild. That would have been really handy as I am
very limited as to where I can provide a pipe.

John

unread,

Dec 13, 2019, 12:04:54 PM12/13/19

to

>
> They were made by Yorkshire Copper and called "Biflow Valves".
> Haven't seen them for years. They worked well so long as the internal
> pipe was fitted. Googled but no results.
>
>
>
>
>

Just been reading about how to remove the radiator. I never had a problem.
Move rad to one side after unscrewing valve and then unscrew the internal
pipe - which on all of mine were nylon - self threated into the valve.
Easily done with pliers.

tabb...@gmail.com

unread,

Dec 13, 2019, 12:36:05 PM12/13/19

to

Unless I'm mistaken you don't need to find one. Just attach a tail as normal at one end & slide microbore inside it. Terminate the join between the 2 using an unequal tee, IYSWIM, not sure how to describe it.

NT

Steve Walker

unread,

Dec 13, 2019, 3:57:25 PM12/13/19

to

Yes, my parents had them on all but one of their radiators (that was a
double panel with the feed between the two panels). Theirs had plastic
piping throughout from the manifolds (10mm, 8mm and 6mm IIRC) all sized
to give the correct flows, so no need for lockshield valves or balancing
(and no method to). My dad worked it all out in advance and put it in in
1972.

After about 30 years, they had to slowly shift to copper and use
conventional valves, as the plastic piping had become brittle and
snapped easily if knocked.

> Googled but no results.

No, I haven't seen them for years.

SteveW

Steve Walker

unread,

Dec 13, 2019, 3:59:26 PM12/13/19

to

I have one radiator with a similar problem. I brought both pipes up at
one end, connected one there and ran the other behind the radiator to
the other end.

SteveW

harry

unread,

Dec 14, 2019, 2:44:33 AM12/14/19

to

The bi-flow valves had a balancing valve incorporated.
You removed a cap and the was a slot headed screw needle valve to do the balancing.

I used them in my parents house, must have been the mid/late 60's.
I used copper pipe, the was no plastic back then

Steve Walker

unread,

Dec 14, 2019, 8:10:03 PM12/14/19

to

There was no screw on my parents'. The whole system was designed to be
balanced by design, hence the multitude of different pipe sizes available.

SteveW

John

unread,

Dec 15, 2019, 4:54:15 AM12/15/19

to

>>>
>>> No, I haven't seen them for years.
>>
>>
>>
>> The bi-flow valves had a balancing valve incorporated.
>> You removed a cap and the was a slot headed screw needle valve to do
>> the balancing.
>>
>> I used them in my parents house, must have been the mid/late 60's.
>> I used copper pipe, the was no plastic back then
>
> There was no screw on my parents'. The whole system was designed to be
> balanced by design, hence the multitude of different pipe sizes
> available.
>
> SteveW
>
>
>

My house was built in 1988 and used them (Maxitwin). Other houses in the
road had conventional ones so I think I was having left over ones used.
Ihad no probelems but eventually when Thermostatic valves were mandated at
bliler change I had them swopped. One pipe was taken behing the radiator to
the other end.

R D S

unread,

Feb 2, 2020, 2:58:10 PM2/2/20

to

On 12/12/2019 16:42, R D S wrote:

I have my answer, about half of it heats up fine, half gradually not
diagonally but i'm not too surprised as it is wider than it is high.

I'm planning to connect a pipe to the feed that runs along the inside of
the bottom of the radiator, thus feeding at the opposite end.
I presume there'd be a benefit to a hole in that pipe near the feed end
and one in the middle (at least).