Hot water recirculation pump good idea? Grundfos?

[CWHEATING]

Page 29.....

https://www.johnguest.com/speedfit/...Plg-Product-Guide-UNPRICED-Z2105-394-0414.pdf

A continuously operated re-circulating system is a water-replenished circulating system which is maintained at a constant high temperature to provide a constant source of hot water. Continuously operated recirculating systems are used to distribute constant hot water to draw off points that may be distant from the source or hot water storage vessel. Continuously operated re-circulating systems are very different from conventional hot water supply and central heating systems found in domestic properties, for which our products have been tested to, under either BS7291:2010 Class S or WRAS approval standards, and for this reason Speedfit products must not be used on any continuously operated re-circulating systems as they are not approved under the current version of these standards

Interesting. So basically what John Guest is saying they haven’t tested their products on recirculating hotwater systems so don’t use it and moan at us if anything goes wrong

 

[CWHEATING]

I guess fresh aerated hot water can take it’s tole on any form of pipework. Especially ones with rubber seals.

 

[dilalio]

Yep... been through this sh!t haven’t we @Dan Robinson

 

[CWHEATING]

Yep... been through this sh!t haven’t we @Dan Robinson

Do tell.

 

[Yorkshirebloke]

Well thanks boys! That's about as comprehensive as it gets. Copper it is then. (More bloody money lol)

I've had a good read over the grundfos comfort pumps. I can't quite decide if the self learning ones are worth all the extra money.
Also as a side note, there are essentially 4 pumps.
2 have a one port to port size, 2 have a bigger port to port size. (80mm and 110mm)
What exactly does that mean to me? I doesn't suggest there Is a difference in flow rate from their specs, so is it just a mounting size for already installed systems? If that's the case, being as I will be installing all of this new is there a preferred size I should choose? The 80mm is considerably cheaper.

Alex

 

[Dan Robinson]

Do tell.

Muppet builder didn't price in for one. Client demanded it. Muppet builder insisted on it being done in plastic.

We insisted he put in writing that he knew it was a schit idea and that we had told him.

@dilalio you still good for tomorrow and Wednesday?

 

[bernardgreen]

I can't quite decide if the self learning ones are worth all the extra money.

Does it "learn" on a daily basis ( all days are the same ) or a 7 day week basis ( Weekends different to weekdays ).

Personally I would opt for the temperature control option.

 

[Dan Robinson]

We use the Auto Adapt Grunny Comforts more or less exclusively unless direct replacement on existing systems:

They work better than traditional time and temperature setups as they're basing the future on and off times based on previous draw off and measuring the water passing from the cylinder back to the pump. Note the little red temp probe under the pump in the second picture - that gets strapped to the hot draw off about a metre from the cylinder.

Decent secondary pump + Decent timer + pipe stat + installation time + installation materials will work out roughly cost neutral to a Grundfos smart pump and a 3 pin plug.


Beware advise from those that do not do this for a living

Buteline which is a crimping system are happy for their product to be used in condition that the Pump is only in use for active periods.

i'd be surprised if Buteline are happy for their crap to carry water full stop, let alone put their fittings through the stress of secondary returns.

 

[bernardgreen]

as they're basing the future on and off times based on previous draw off and measuring the water passing from the cylinder back to the pump.

Does it memorise the draw off pattern over a week thus allowing for Saturday and Sunday to be different from weekdays ?
Can it do that accurately from just a single temperature sensor that is not positioned at the point of delivery ?

 

[dilalio]

@dilalio you still good for tomorrow and Wednesday?

Yep. Txt me where and when.

 

[Dan Robinson]

Does it memorise the draw off pattern over a week thus allowing for Saturday and Sunday to be different from weekdays ?
Can it do that accurately from just a single temperature sensor that is not positioned at the point of delivery ?

Couldn't be sure of the exact number of days. And it is not just a single sensor at the point of delivery. It is a sensor at the point of draw off and one in the pump. So it know when the system is both up to temperature and when it is being used using ΔT/time.

 

[Dan Robinson]

Yep. Txt me where and when.

Will do when i find the phone.... its Highgate though.

 

[dilalio]

Does it memorise the draw off pattern over a week thus allowing for Saturday and Sunday to be different from weekdays ?
Can it do that accurately from just a single temperature sensor that is not positioned at the point of delivery ?

Yes Bernard and it will also have a cup of tea and jam on toast ready for you at 7:30 on a Saturday morning, shortly before you use the washbasin!

 

[bernardgreen]

from just a single temperature sensor that is not positioned at the point of delivery

And it is not just a single sensor at the point of delivery.

The system that worked for a B&B with 4 en-suite rooms was a thermostat on the point furthest from the cylinder. When that went cool the pump ran long enough to bring hot water to that point. Simple and it worked for years.

 

[bernardgreen]

ready for you at 7:30 on a Saturday morning,

Too late, would need to be 6:30 at the latest. and marmalade is prefered.