Hot water recirculation pump good idea? Grundfos?

[Yorkshirebloke]

Wow, thanks so much for the info boys.
Had a little Google of the occupancy sensors.... Wow how very cool! Only thing is, for instance in the kitchen if you pop to the sink to wash your hands, the hot water won't be there? I appreciate that in a toilet situation, it's a good thing as you aren't probably going to wash your hands for a minute or 2.
Any way round that?
As for Teeing into the cold feed, does that not waste a smidge of energy? I was lead to believe that returning the slightly cooler water towards the top of the tank would save energy rather than pitting that back into the bottom. Is this noticeable?
On the Joules tanknits got the outlet/inlet already there, should I make use of it or plumb it back into the cold feed with a swept T and a NR valve.

 

[CWHEATING]

Wow, thanks so much for the info boys.
Had a little Google of the occupancy sensors.... Wow how very cool! Only thing is, for instance in the kitchen if you pop to the sink to wash your hands, the hot water won't be there? I appreciate that in a toilet situation, it's a good thing as you aren't probably going to wash your hands for a minute or 2.
Any way round that?
As for Teeing into the cold feed, does that not waste a smidge of energy? I was lead to believe that returning the slightly cooler water towards the top of the tank would save energy rather than pitting that back into the bottom. Is this noticeable?
On the Joules tanknits got the outlet/inlet already there, should I make use of it or plumb it back into the cold feed with a swept T and a NR valve.

No because heat rises. The hotwater displaces the cold.
Remember cold fill goes in the bottom of cylinder and the draw off to the taps is at the top of your cylinder regardless if you have a return pump/circulater

 

[Yorkshirebloke]

Ok, totally with you on that.
So, I'll plumb it into the mains in as you suggested.

Now, I need a pump. Found a good grundfos but no timer on it. Although that's not exactly a biggie I can put a timer in a plug socket.
What do you make of these?
https://www.mrcentralheating.co.uk/...MItunkiZuV2wIVq7ftCh2FLwqQEAQYAiABEgICxPD_BwE
Seem cheap enough and a small unit. But at half the price of the grundfos it set alarms bell ringing lol

 

[CWHEATING]

Ok, totally with you on that.
So, I'll plumb it into the mains in as you suggested.

Now, I need a pump. Found a good grundfos but no timer on it. Although that's not exactly a biggie I can put a timer in a plug socket.
What do you make of these?
https://www.mrcentralheating.co.uk/...MItunkiZuV2wIVq7ftCh2FLwqQEAQYAiABEgICxPD_BwE
Seem cheap enough and a small unit. But at half the price of the grundfos it set alarms bell ringing lol

I’ve only ever fit grundfos return pumps.
That one you posted a link to is only 1/2 inch. It would be better to use a grundfos with 3/4 pump valve unions. A better flow rate will be attained.

 

[Yorkshirebloke]

You see, that's why I ask the pros!
I'll fit the grundfos then. What's another 100 quid on 3k parts lol.
Thanks so much for the help, and everyone else who joined in. Really appreciate it.

 

[CWHEATING]

Just thought, if you decide to use a sweep T makes sure it’s not a black iron one. Stainless or copper only on potable water.

 

[Yorkshirebloke]

Yeah same as the pump. Brass or stainless.
Which incidentally means it doubles in price lol

 

[Bodd]

Not read through. If not mentioned that if your having a secondary return pump I advise that the hotwater supply is done in Copper in its entirety. Best not use push fit system of any sort.

Bod

 

[Bodd]

Grundfoss do a with an auto adapt memory function . It learns the Patten of your usage. So will flick on just before use and think it also clicks on with activity.

 

[Yorkshirebloke]

Thanks for the advice Bodd.
I will happily pipe it in copper, but just for curiosity why can't the secondary return be done in plastic?

I'll have a look at the grundfos site again and see if I can find it

 

[CWHEATING]

Thanks for the advice Bodd.
I will happily pipe it in copper, but just for curiosity why can't the secondary return be done in plastic?

I'll have a look at the grundfos site again and see if I can find it

I was wondering that too.

 

[Razor900]

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

 

[Bodd]

Thanks for the advice Bodd.
I will happily pipe it in copper, but just for curiosity why can't the secondary return be done in plastic?

I'll have a look at the grundfos site again and see if I can find it

What Razor has said apply s ( to my knowledge) all manufactures of push fit.

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. This is where the Grundfoss auto adapt bronze pump comes in .Or a pump on a timer ect ect.

Bod

 

[JohnD]

I formerly had a Bronze Grundfos, it was startlingly expensive. I don't know if the newer stainless version is as much.

 

[lostinthelight]

This pump has built in non return valve and only consumes 8watts I will run mine on a timer as the adaptive are much more expensive.the one the op links to is 26 watts and 1.2m head.
GRUNDFOS COMFORT 15-14 BX PM (110) BRASS COMFORT HOT WATER CIRCULATOR PUMP 240V
litl