Shower pump problem

[davhar]

Have a client whose shower pump seems to be drawing air into the hot side of the pump but I can not see why.

Set up is:

• Property is a one bed one bathroom property occupied by a couple
  airing cupboard next to bath room.
  hot cylinder in airing cupboard with tank mounted above it.
  Salamander ESP50CPV negative head pump is on airing cupboard floor.
  Pump is about 1 month old.
  Dedicated cold feed from CWSC direct to pump.
  Dedicated hot feed from hot cylinder via Essex flange with dip tube.
  Shower bar is an Ideal Standard Alto Therm
  

It works whenever I attend, flow measured with shower bar removed as 14 l/min on cold side 17 l/min on hot side and runs for long period. When customer uses shower runs for about 1 min before pressure drops and hot side of pump goes noisy as if air has accessed pump. Any ideas?

 

[slapper]

Have a client whose shower pump seems to be drawing air into the hot side of the pump but I can not see why.

Set up is:

• Property is a one bed one bathroom property occupied by a couple
  airing cupboard next to bath room.
  hot cylinder in airing cupboard with tank mounted above it.
  Salamander ESP50CPV negative head pump is on airing cupboard floor.
  Pump is about 1 month old.
  Dedicated cold feed from CWSC direct to pump.
  Dedicated hot feed from hot cylinder via Essex flange with dip tube.
  Shower bar is an Ideal Standard Alto Therm
  

It works whenever I attend, flow measured with shower bar removed as 14 l/min on cold side 17 l/min on hot side and runs for long period. When customer uses shower runs for about 1 min before pressure drops and hot side of pump goes noisy as if air has accessed pump. Any ideas?

Why wasn't a positive head pump used if below cylinder, also think about fitting non return vavles

 

[davhar]

Have a client whose shower pump seems to be drawing air into the hot side of the pump but I can not see why.

Set up is:

• Property is a one bed one bathroom property occupied by a couple
  airing cupboard next to bath room.
  hot cylinder in airing cupboard with tank mounted above it.
  Salamander ESP50CPV negative head pump is on airing cupboard floor.
  Pump is about 1 month old.
  Dedicated cold feed from CWSC direct to pump.
  Dedicated hot feed from hot cylinder via Essex flange with dip tube.
  Shower bar is an Ideal Standard Alto Therm
  

It works whenever I attend, flow measured with shower bar removed as 14 l/min on cold side 17 l/min on hot side and runs for long period. When customer uses shower runs for about 1 min before pressure drops and hot side of pump goes noisy as if air has accessed pump. Any ideas?

Why wasn't a positive head pump used if below cylinder, also think about fitting non return vavles

Pump is below hot water cylinder but shower head in bathroom is at about same height as top of CWSC, so no guarantee of free flow to shower head.

 

[slapper]

Fit a non return valve on the hot outlet, have you fitted an anti gravity loop to the hot outlet from the Essex flange?

My mistake dude, was thinking pump was higher than cylinder. Disregard what I wrote,(been on the sherbert)

 

[picasso]

How big is the Cold water tank ?

 

[davhar]

Fit a non return valve on the hot outlet, have you fitted an anti gravity loop to the hot outlet from the Essex flange?

My mistake dude, was thinking pump was higher than cylinder. Disregard what I wrote,(been on the sherbert)

Tried it with and without the non return on the hot outlet from the pump and that does not seem to make a difference.

Have not fitted an anti gravity loop, but if I did as far as I can see I would end up with an inverted loop as pump is at base of hot cylinder, and Salamander say the inverted loop is a no no.

 

[davhar]

How big is the Cold water tank ?

Cold tank is about 55 gallons, not ideal but recharge time after any testing I have done has not been long enough to indicate a water shortage problem.

 

[picasso]

I would check the temp of the water is less than 60c going into the pump, it could also be gate valve not open fully on cylinder cold feed or limescale blocking the cold feed at the bottom of the cylinder.