shower pump

[pompeyfc]

hi ive just done my bathroom and fitted a new shower thermal mixer i have low hot water pressure so i wanna get a pump i have a gravity system cold tank in loft hot water cyclinder on 1st floor but i will need to go back up and over with the pipe work into the loft to the bathroom and down so not sure if i need a positive or negitive pump and would there be any benefits getting a twin pump or singel and haven the cold coming off the mains

 

[steadyon]

1. Whether you need a positive or negative head pump depends on the distance between the shower head in its normal position and the base of the cold water storage cistern (CWSC). Check the manufacturer's specifications for this distance relevant to the pump you are going to buy. As a rule of thumb, 600 mm is usually enough to start a positive head pump.
2. If you have the cold off the mains and pumped hot (single sided pump) you may have difficulty balancing the pressure. You'd be much better advised to go for a double sided pump.
3. The pump will need separate feeds from the CWS and the hot water cylinder (HWC).
3a. The feed from the CWSC needs to be taken from a slightly lower level than the feed from the CWSC to the HWC. This is to avoid scalding if the cold water runs out.
3b. The feed from the HWC must be in accordance with the manufacturer's specification. This normally requires a special flange fitting to the HWC to avoid aeration of the hot water feed to the pump.
3c. The best place for the pump is level with the base of the hot water cylinder. Not under the bath.
4. My preference is the Stuart Turner Monsoon range. Quite expensive, but last a long time and you can get spares if necessary.

 

[pompeyfc]

1. Whether you need a positive or negative head pump depends on the distance between the shower head in its normal position and the base of the cold water storage cistern (CWSC). Check the manufacturer's specifications for this distance relevant to the pump you are going to buy. As a rule of thumb, 600 mm is usually enough to start a positive head pump.
2. If you have the cold off the mains and pumped hot (single sided pump) you may have difficulty balancing the pressure. You'd be much better advised to go for a double sided pump.
3. The pump will need separate feeds from the CWS and the hot water cylinder (HWC).
3a. The feed from the CWSC needs to be taken from a slightly lower level than the feed from the CWSC to the HWC. This is to avoid scalding if the cold water runs out.
3b. The feed from the HWC must be in accordance with the manufacturer's specification. This normally requires a special flange fitting to the HWC to avoid aeration of the hot water feed to the pump.
3c. The best place for the pump is level with the base of the hot water cylinder. Not under the bath.
4. My preference is the Stuart Turner Monsoon range. Quite expensive, but last a long time and you can get spares if necessary.

thanks for the reply i have this shower BUY NOW Milan Modern Chrome Thermostatic Shower - https://www.victorianplumbing.co.uk/milan-square-thermostatic-bar-shower-valve-riser-kit-chrome and the rain full head is about 450mm from the bottom of the cold tank the other head is about 600mm ish i forgot to say i have got the S Tank Flange Fitting so with this then would be best to get a negitive pump as postitve wont be any good for the main rain full head on the shower

 

[steadyon]

1. Decide what pump you want, then look up the manufacturer's documentation.
2. Negative head will work in most situations but is more expensive.

 

[pompeyfc]

1. Decide what pump you want, then look up the manufacturer's documentation.
2. Negative head will work in most situations but is

ok thanks i was looking at stuart turner shower mate in screwfix i looked at the instruction manual and it says Outlet head must be below bottom of cold water tank and able to pass a minimum of 0.8 l/min of gravity flow so how would i test the flow