Silly question; why do we use motorised diverter valves?

[Googlyhead]

Aside from the obvious; "to divert..."

In the UK;
An s-plan is usually a pump, with a valve for the tank, and a valve for the heating.

Wouldn't the better option simply be a pump on each circuit (instead of the valves)? Two pretty reliable items instead of three (everyone seems to complain about valves!), no more expensive, more controllable, less wasted power...
Worst case; if there's any risk of back flow, add a NRV.

 

[transam]

Grundfoss came out with a double pump set up a good while back , never seemed very popular ? u can use 2 stand alone pumps if u want ?

3 way valve ( mid postion ) 1 port will always be open , can negate a by pass (sometimes ) any unvented cylinder will always require a MV irrespective of 2 pumps , 3 way vave ect ! some boilers require a pump over run ! 2 pumps can cause problems on open systems ( maybe ??)

 

[transam]

double post

 

[Agile]

The design uses the cheapest parts to do the job.

pumps are expensive and heavy!

 

[moggridgeplumbing]

It looks much neater zoneing with MV's than seeing banks of bulky pumps.

And what about increase the size of system boilers to incorporate three pumps!

 

[picasso]

if you use more than one pump you have to use relay/s, as you know relays are extremely complicated so its easier to wire up zone valves without actually knowing what your doing.

 

[misterdubya]

Aside from the obvious; "to divert..."

In the UK;
An s-plan is usually a pump, with a valve for the tank, and a valve for the heating.

Wouldn't the better option simply be a pump on each circuit (instead of the valves)? Two pretty reliable items instead of three (everyone seems to complain about valves!), no more expensive, more controllable, less wasted power...
Worst case; if there's any risk of back flow, add a NRV.

Stick with your google'ies.

Mr. W.

 

[Googlyhead]

The design uses the cheapest parts to do the job.

pumps are expensive and heavy!

I've no experience of buying in bulk, but they don't seem to be. Standard price for a typical pump seems to be a little more than a decent (danfoss / honeywell) valve; some pumps are cheaper still. Admittedly the very high efficiency pumps would be over £100 a set, but then you would probably be getting to a pretty specialist system.

Grundfoss came out with a double pump set up a good while back , never seemed very popular ? u can use 2 stand alone pumps if u want

Didn't know there was (once) such a standard system. Will have to do some reading...!

 

[misterdubya]

Well, this is IT

Mr. W.

 

[Googlyhead]

It looks much neater zoneing with MV's than seeing banks of bulky pumps.

And what about increase the size of system boilers to incorporate three pumps!

Who said three? You won't need the main pump; just one where each valve is now!
Who said in the boiler? Once upon a time, pumps were a separate bit of equipment...

Yes; lots of zoning is probably better with individual actuators, But a basic heating and/or hot water system selecting between the two circuits is what I was thinking of.

 

[Googlyhead]

Stick with your google'ies.

Mr. W.

I try to.

if you use more than one pump you have to use relay/s, as you know relays are extremely complicated so its easier to wire up zone valves without actually knowing what your doing.

and you can't just wire in a pump as if a 2-port valve? Bar the overrun mentioned (there'll probably be a requirement for a high efficiency control centre in another year anyway!) it's either circuit on or circuit off!

edit; Actually; there is a wiring centre; http://www.gasapplianceguide.co.uk/pumpplan.htm / edit

Well, this is IT

Mr. W.

Umm. Ok. Just get two 'normal' pumps then! More flexible and cheaper. I can see why it didn't take off.[/i]

 

[misterdubya]

I can see why it didn't take off.

From a plumbing point of view, so can I!

Mr. W.

 

[mickyg]

without a valve you leave the circuits open your not using. so your rads will heat up when the hot water is on.

 

[Agile]

The Grunfos pump plan got round that by having a spring loaded non return valve.

They were a good idea but just were not accepted.

They made so much publicity for it and it went nowhere.

Yet the booster pump is a wonderful job and they have never publicised it at all.

 

[Agile]

The Grunfos pump plan got round that by having a spring loaded non return valve.

They were a good idea but just were not accepted.

They made so much publicity for it and it went nowhere.

Yet the booster pump is a wonderful job and they have never publicised it at all.