Stainless steel hot water cylinder

[Cowboy Pete]

Three years ago I installed a new 50 gallon cold water tank in my loft on a platform 54 inches above the ceiling and a new stainless steel 140 litre hot water cylinder which had 22mm welded flanges for inlet and outlets.

I then built a shower room in a spare bedroom fed by a Salamander CT50 pump. I made a special outlet for the shower by cutting a 22mm hole in an immersion heater blanking plug and soldering a 22mm copper pipe which extends 150mm into the hot water cylinder. From this I used 22m plastic pipework to the Salamander pump sited in the loft above the shower room and included an anti gravity loop as per the instructions.

Now when my wife runs her bath the hot water will not feed the shower. I know the instructions say the feed to the hot tank must be 28mm in this situation but this is not possible.

[FONT=&quot]Would running 28mm pipe from the cold tank to the 22mm inlet using a reducer at the hot tank help or would using copper pipe instead of plastic solve the problem ?[/FONT]

 

[Chalked]

Is the cylinder in the loft?

 

[ShaunCorbs]

and did you get a negative head pump aswell?

 

[Cowboy Pete]

The hot water cylinder is on the first floor not in the loft.
I do not understand about a "negative Head pump". The instructions for the Salamander show it can be installed in the loft with an anti gravity loop from the outlet of the hot tank. It recommends installation near the hot water cylinder but this is not possible in my house.

 

[MSM]

The water needs to flow through the pump to activate the switch inside so the pump would engage. By the sounds of it you got negative pressure so the switch never activates = no hot water. you can buy a negative head pump or move the existing pump down so you achieve a positive head. See manual for the pump. My guess 2m should be enough.

 

[ShaunCorbs]

The hot water cylinder is on the first floor not in the loft.
I do not understand about a "negative Head pump". The instructions for the Salamander show it can be installed in the loft with an anti gravity loop from the outlet of the hot tank. It recommends installation near the hot water cylinder but this is not possible in my house.

you need a negative head pump if your not installing it by the cylinder no ifs or buts

and this is from the Salamander manual

 

[SimonG]

Its all quite clear in the pump mi's. Move it or change it.

 

[GasmanxxxR1]

I always thought that a negative head pump was for when the shower outlet was higher than the cwsc regardless of the pump position. Shows what i know!

 

[ShaunCorbs]

I always thought that a negative head pump was for when the shower outlet was higher than the cwsc regardless of the pump position. Shows what i know!

yes and no for a normal pump, you still need gravity pressure coming through the pump and the pump turns on via a flow switch,

negative head pump senses pressure drop when a tap, shower valve, etc. is opened. and the pump starts up

if you mount the pump in the loft you wont get any flow through it as its on nearly the same level of the cwsc