shower pump situation

[ethelfleda]

Hi, a bit of advice please on putting in a Salamander CT55 shower pump (1.7 bar) on the hot supply to a shower mixer via a double check valve just under the mixer. (cold mains pressure 2.0 bar)

I had originally intended this to go under the bath, but it is too big! ditto under the floorboards in the bedroom. The only place left is in the airing cupboard which is downstairs but I have a couple fo concerns:

1. the hot water output from the vented cylinder is right at the top of the cylinder (of course). which is on a shelf ... so I would need nearly 2metres of 22mm down to the floor & 2 meters back up again. is this normal? acceptable? if not, how do I get round it?

2. the input to the pump is 15mm/1/2 inch - do I need to reduce the pipe width (in both directions) or can I get 22mm/1/2 inch flexi connectors? if so, do you know where from?

3. shortly after the pipe leaves the cylinder it meets a t connector. One branch of this goes off to the bathroom (& probably down to the kitchen afterwards - it is all a bit up & over), the other seems to go up to the loft - presumably to overflow into the header tank which is only 2 ft above the shower head - bearing in mind the resistance of the shower head, is this height difference sufficient to stop the pumped water going up the overflow pipe instead of to the shower? (swirl shower mixer from SF). (I cannot connect after the t connector because of the bedroom floorboard situation mentioned above)

thanks for any help.

 

[seco services]

1, a ct55 is a twin pump.
2, you plan on running the shower on pumped hot mains cold. run them both off the pump not mixed pressures.
3, why run in 22mm when 15mm is ok for a ct pump and the length you are going.
4, fit a proper flange for the cylinder not t ing of the vent etc, use a surrey or essex flange.

 

[ethelfleda]

respectfully, a ct55 is a single pump, the ct 50 is the twin pump.

it's a long story, but in the end pumping up the pressure on the hot & using a double check valve seems to be the best solution - plumbing in a new output from the cold water tank etc, is due to the layout of the house & the rest of the system, just not practical.

the h/w pipework is already 22mm - I just want to up the pressure - ideally just for the shower, but I can't find a way to make that possible, so now for the rest of the sytem as well. Are you saying that I need to fit another output to the cylinder, or does the surrey flange attach inside the original output (or is there likely to be one there already?)

 

[seco services]

out the top of your cylinder is a 22mm pipe.
a surrey flange screws into the top of your cylinder and the existing pipe screws into the top of the flange and the shower outlet then comes out the side of the flange

http://www.bathroomexpress.co.uk/images/techflow_turbo_installation_manual_fig3.jpg

and the idea of running your shower of hot of pump, cold mains 9/10 times will cause problems

 

[ethelfleda]

that suggests that I need to put in completely new pipework for the shower all the way from the cylinder? What happens if I just pressurise the existing pipework using the pump - it is going to a straight forward bar mixer mounted on the bath.?

I know that equal pressure is the best, but I am hoping that the smallish difference I should get (0.2 bar) will not be too much of a problem - especially with the double check to prevent the cold pushing backwards.