Twin pump: Alter HWC pipework or fit flange?

[benraz69]

Hi all,

I have a Stuart Turner Monsoon 3 bar pump which sits at the base of my HWC. When I originally fitted the pump, I just plumbed it straight into the existing H&C feeds for convenience - knowing that I'd have the opportunity to alter it later (This weekend, I'm redoing most of the pipework going to/from the HWC as part of another project).

The pump is currently plumbed in as below. With the left hand copper feed going to the pump and the right hand one going up to the F&E tank.

The pump works fine, no problems. My only concern is that, AIUI, the life of the pump can be compromised due to it dragging in air from the F&E pipe. I've read that a Surrey flange is too restrictive for a whole house pump & that an Essex flange can affect the HWC storage capacity. Is there a right answer?

Could I plumb it up like this-? This way, the pump is much less likely to drag in air from the F&E pipe, whilst still allowing the HWC to vent. Thoughts?

 

[rjm2k]

Don't know the answer, but I do know that air in the Cylinder is also a risk which is why a flange is used to take the water below the point where air will have settled.

 

[Breesey]

Use a warix flange, or similar and makesure the cold feed is correctly installed from cold tank ie BELOW hot cylinder feed.

 

[benraz69]

Don't know the answer, but I do know that air in the Cylinder is also a risk which is why a flange is used to take the water below the point where air will have settled.

Didn't realise there would be air in the HWC. I assumed the water level on the hot side would be the same as in the CWS tank, i.e. somewhere way up in the F&E pipe-?

Use a warix flange, or similar and makesure the cold feed is correctly installed from cold tank ie above hot cylinder feed.

Thanks, but from a quick google the Warix looks very similar to a Surrey flange. I'm guessing it's less restrictive somehow-? Also, not sure I understood the second half of your reply, sorry

 

[rjm2k]

Didn't realise there would be air in the HWC. I assumed the water level on the hot side would be the same as in the CWS tank, i.e. somewhere way up in the F&E pipe-?

Water is full of air, whilst a HW cylinder doesn't boil the water, think what
happens in your kettle or a pan as the water is heated up.

Also, not sure I understood the second half of your reply, sorry

Your pump installation instructions will detail the CW connection you need to make.

 

[Breesey]

Thanks, but from a quick google the Warix looks very similar to a Surrey flange. I'm guessing it's less restrictive somehow-? Also, not sure I understood the second half of your reply, sorry

Why the 'but'? This type of flange (warix/surrey) is an easy way of installing a pump with an air free connection, as is required.

The cold feed connection should be inserted into the cold tank BELOW the level of the cold feed to the HWC.

 

[benraz69]

Why the 'but'? This type of flange (warix/surrey) is an easy way of installing a pump with an air free connection, as is required.

Sorry, my understanding is that a Surrey flange was too restrictive for a whole house pump & I don't see how a Warix flange differs.

The cold feed connection should be inserted into the cold tank above the level of the cold feed to the HWC.

Thanks for the tip, why is this?

 

[Charnwood]

View media item 57784

 

[Breesey]

Sorry, my understanding is that a Surrey flange was too restrictive for a whole house pump & I don't see how a Warix flange differs.

Ok, sorry didn't read your OP properly! So you're pumping all hot outlets?? There could be some reduction in performance if you use more than one outlet at once but otherwise the warix/surrey flange should be fine - at least you won't be dragging air.
You could fit a 28mm essex flange but this isn't such a straight forward job as the warix

Thanks for the tip, why is this?

Because the cold tank feeds the HWC at the same time as it feeds cold to the pump the pump outlet should be BELOW the hot outlet for safety reasons should supply to the cold tank fail.

 

[Breesey]

I earlier incorrectly said that the cold pump feed should be above the cold feed to the HWC.

To clarify: Cold pump feed should be BELOW HWC cold feed - apologies for this.

Particularly annoying as it was only 2 weeks ago I last installed a shower pump Correctly I might add!!