Mixer tap pressure low

The 0.2 is to cover vented domestic water systems like yours.

The 5 bar will cover unvented (mains pressure).

I’d just get a new tap.

Where is the tap? Bathroom/kitchen? Are both supplies the same pressure?
Kitchen, mains cold would be high and vented hot would be low. Just something to bear in mind as if you install a thermostatic tap here, the cold will force up the hot pipe.

There are a few thermostatic taps suitable for the above situation.

Two options upgrade your system to mains pressure and keep the new tap or change for a low pressure tape eg with the good old 1/2 washer style

Timmy D said:

The 0.2 is to cover vented domestic water systems like yours.

The 5 bar will cover unvented (mains pressure).

I’d just get a new tap.

Where is the tap? Bathroom/kitchen? Are both supplies the same pressure?
Kitchen, mains cold would be high and vented hot would be low. Just something to bear in mind as if you install a thermostatic tap here, the cold will force up the hot pipe.

There are a few thermostatic taps suitable for the above situation.

Click to expand...

Is a kitchen mixer. I spoke to a guy at Stuart Turner yesterday discussing this. It was decided what was needed was a negative head pump due to uneven pressures available. Was all good until I was told the pump must be no further than 4m away from the HW cylinder , so that knocked that on the head. So am now looking for a new tap. And as you rightly state needs to be the correct
tap so if mixing the cold does not push the hot water backwards.

Bogart said:

Is a kitchen mixer. I spoke to a guy at Stuart Turner yesterday discussing this. It was decided what was needed was a negative head pump due to uneven pressures available. Was all good until I was told the pump must be no further than 4m away from the HW cylinder , so that knocked that on the head. So am now looking for a new tap. And as you rightly state needs to be the correct
tap so if mixing the cold does not push the hot water backwards.

Click to expand...

This is really a FYI and to clear up any potential misunderstanding.

You said a negative head pump was recommended due to uneven pressures...

The options are either a positive or negative head pump.

The “default” as such is a positive head pump.

A negative is used when the highest outlet (typically a shower head) is 600mm or less below the bottom of the cold water tank.

A positive head pump relies on the tank water pressure to start the pump. When it’s close to the tank, there’s insufficient pressure to start it. So we use a negative pump.

You can’t put the pump next to the cylinder?

Or depending on age of current cylinder, upgrade to an unvented (mains pressure/flow permitting).

Timmy D said:

This is really a FYI and to clear up any potential misunderstanding.

You said a negative head pump was recommended due to uneven pressures...

The options are either a positive or negative head pump.

The “default” as such is a positive head pump.

A negative is used when the highest outlet (typically a shower head) is 600mm or less below the bottom of the cold water tank.

A positive head pump relies on the tank water pressure to start the pump. When it’s close to the tank, there’s insufficient pressure to start it. So we use a negative pump.

You can’t put the pump next to the cylinder?

Or depending on age of current cylinder, upgrade to an unvented (mains pressure/flow permitting).

Click to expand...

Stuart turner said a positive pressure pump would not work in my situation. Pump next to the cylinder would be possible but not without a lot of additional pipework involved. The hot water exits the cylinder going right. There is about

As they say a picture paints a thousand words. Attached are 2 photos.
Second shows arrangement at top of HW cylinder. The 28mm pipe exiting right is the hot feed to all baths and basins. It is approx 300mm in length with a gate valve in the middle before it disappears behind the plasterboard. The 22mm pipe exiting directly above the HW cylinder is the pipe feeding a shower via a Stuart Turner twin monsoon seen in first pic the copper pipe coming in from top right. Now my dilemma is/was how to fit a pump. The only real tap with a problem is the monobloc in the kitchen, with as mentioned before a pathetic flow rate, caused by it being a high pressure tap on a low pressure setup. All other hot outlets are fine.
The ST pump in first pic is a 2 bar twin Monsoon, feeding just the one shower. I did think of a few options. One was to put a pump
on the shelf above directly over where the 28mm gate valve is. Dump the gate valve and insert a pump into the pipework there. Not sure how it would like bouncing around on a slatted shelf though I could beef that up. To put a second pump on the floor like the current pump would involve a lot more pipework. One other option I thought of was make the ST pump do the whole house hot.
Or just buy a low pressure tap.

ShaunCorbs said:

Two options upgrade your system to mains pressure and keep the new tap or change for a low pressure tape eg with the good old 1/2 washer style

Click to expand...

Latter option much cheaper and simpler.