Hello,

In my heating system I have a WILO RS25/6-3 pump.

I would like to buy another similar one, but this WILO part seems to be
unavailable.

It is a 130mm pump and there seem to be many choices that are
mechanically compatible...

I would to make sure I buy something that equals or exceeds the performance.

So can anybody confirm that: RS25/6-3 means

* 25 litres/minute
* 6 Metres head
* 3 speed

If not can anybody explain, please?

D

On Dec 14, 6:18*am, Vortex10 wrote:
Hello,

In my heating system I have a WILO RS25/6-3 pump.

I would like to buy another similar one, but this WILO part seems to be
unavailable.

It is a 130mm pump and there seem to be many choices that are
mechanically compatible...

I would to make sure I buy something that equals or exceeds the performance.

So can anybody confirm that: * RS25/6-3 means

* * * * 25 litres/minute
* * * * 6 Metres head
* * * * 3 speed

If not can anybody explain, please?

D

There is no convention on circulating pumps. You might be right.
Most domestic circulating pumps are of similar capacity. Unless your
pump is running on the maximum speed you won't have a problem.

You should note that the heads /capacities given for pumps are not
simultaneous.
Ie on the above assumption, the pump would develope 6m head at zero
flow and 25l/min at zero head. This just shows it's upper limits, in
practice it would run some where intermediate.
The curve is non-linear too. ie it wouldn't do 12.5l/min at 3m head.
The manufacturers provide a graph so you can read off how much water
it shifts at various pressures.

http://www.cheresources.com/centrifugalpumps5.shtml

The curve you are interested in is the system curve on the graph shown.

On Dec 14, 6:18*am, Vortex10 wrote:
Hello,

In my heating system I have a WILO RS25/6-3 pump.

I would like to buy another similar one, but this WILO part seems to be
unavailable.

It is a 130mm pump and there seem to be many choices that are
mechanically compatible...

I would to make sure I buy something that equals or exceeds the performance.

So can anybody confirm that: * RS25/6-3 means

* * * * 25 litres/minute
* * * * 6 Metres head
* * * * 3 speed

If not can anybody explain, please?

D
There is no convention on domestic size circulating pumps. You might
well be right.
Most domestic circulating pumps are of similar capacity. Unless your
pump is running on the maximum speed you won't have a problem.

You should note that the heads /capacities given for pumps are not
simultaneous.
Ie on the above assumption, the pump would develope 6m head at zero
flow and 25l/min at zero head. This just shows it's upper limits, in
practice it would run some where intermediate.
The curve is non-linear too. ie it wouldn't do 12.5l/min at 3m head.
The manufacturers provide a graph so you can read off how much water
it shifts at various pressures.


http://www.cheresources.com/centrifugalpumps5.shtml


The curve you are interested in is the pump. curve on the graph
shown.

On 14/12/2010 11:29, harry wrote:
On Dec 14, 6:18 am, wrote:
Hello,

In my heating system I have a WILO RS25/6-3 pump.

I would like to buy another similar one, but this WILO part seems to be
unavailable.

It is a 130mm pump and there seem to be many choices that are
mechanically compatible...

I would to make sure I buy something that equals or exceeds the performance.

So can anybody confirm that: RS25/6-3 means

* 25 litres/minute
* 6 Metres head
* 3 speed

If not can anybody explain, please?

D

There is no convention on circulating pumps. You might be right.
Most domestic circulating pumps are of similar capacity. Unless your
pump is running on the maximum speed you won't have a problem.

You should note that the heads /capacities given for pumps are not
simultaneous.
Ie on the above assumption, the pump would develope 6m head at zero
flow and 25l/min at zero head. This just shows it's upper limits, in
practice it would run some where intermediate.
The curve is non-linear too. ie it wouldn't do 12.5l/min at 3m head.
The manufacturers provide a graph so you can read off how much water
it shifts at various pressures.

http://www.cheresources.com/centrifugalpumps5.shtml

The curve you are interested in is the system curve on the graph shown.

I have not been able to find any definitive datasheet on the WILO
pump I have, from anywhere!

This particular pump feeds the upstairs heating in my home, and was new
last year. It simply does not have as much "jaffa" as the old pump and
heat struggles to reach the most remote rads as a result. System is
sealed/pressurised and I have balanced as best I can.

Assuming Screwfix can deliver, I'm going to install a higher flow rate
pump at the weekend and see what happens. I expect it will improve matters.

On Dec 14, 6:18*am, Vortex10 wrote:
Hello,

In my heating system I have a WILO RS25/6-3 pump.

I would like to buy another similar one, but this WILO part seems to be
unavailable.

It is a 130mm pump and there seem to be many choices that are
mechanically compatible...

I would to make sure I buy something that equals or exceeds the performance.

So can anybody confirm that: * RS25/6-3 means

* * * * 25 litres/minute
* * * * 6 Metres head
* * * * 3 speed

If not can anybody explain, please?

D

You might want to look at automatic speed control.
http://net.grundfos.com/doc/webnet/p...edcontrol.html

Expensive though as I recall.

Am 14.12.2010 07:18, schrieb Vortex10:
Hello,

In my heating system I have a WILO RS25/6-3 pump.

So can anybody confirm that: RS25/6-3 means

* 25 litres/minute
Negative. 25 is the nominal diameter of the shaft. ca. 25 mm , about 1 inch.
* 6 Metres head
Positive.
* 3 speed

Dunno. Sorry.

HTH