feeds for a twin impeller pump (pics)

[dholi]

new to this site, trying my best to be as clear as crystal

im a fairly keen diyer and am looking to connect a salamander twin impeller pump to a new mixer shower. at the moment i have a shower mixer tap which is pretty useless.
my setup is as follows:
- cold from mains direct into kitchen and bathroom taps
- hot water is supplied from a double feed indirect hot water tank in a room 2m away from the bathroom but on the same floor (tank sits about a metre above the ground). there is no additional cold water tank to supply the hot water tank.
- I have a boiler in the kitchen downstairs which i presume controls the heating but there seems to be a heating pump connected to the hot water tank too, so im not too sure.

I've read and understood that mains pressure cannot work on pumps so my question is, how do i go about connecting hot and cold from this hot water tank. i can run fresh pipework into the bathroom and locate the shower at a distance of 3m from the tank with pump sitting directly below the water tank. alternatively i can locate the pump underneath the bath tub, at a distance of 2m from the tank.
as can be seen, im an amateur!
any advice would be highly appreciated.

pictures:

 

[gas4you]

You either need to locate a gravity supply for the cold from your elson or perhaps fit a single feed booster pump just for the hot. This is not perfect but may work.

 

[Gasguru]

The Elson tank incorporates a very small cold water tank. Its possible even a small shower pump would drain this tank during showering. Also the height of the tank may not be sufficient for the pump flow switches to operate.

Another solution might be a venturi shower eg Trevi Boost. Check specs. carefully though.

 

[Dan Robinson]

As GG said - you wouldn't catch me fitting a pump to one of these...

 

[dholi]

thanks for the advice..
buggaa!
no way i can afford another tank at the mo
i live alone in a 1 bedroom flat so am not really too concerned about water running out etc, just want to be able to have a quick 5 minute shower b4 work in the mornings..
i would like to go ahead with the install for now and then at a later date get the tank changed to one that can cope along with the pump.
question is, how do i gain access to the gravity cold supply from this tank??

 

[Gasguru]

Talk to Elson they may have suggestions.

Look at the diagram on the side on the unit it shows the hot and cold outlets.

I suggest you choose a cheap low powered (low pressure) pump. If possible find a regenerative pump (also known as peripheral pump), these pumps can cope with considerble air ingress into the water. Most pumps are however centifugal...they are intolerant of "bodged" installations such as this.

Running out of water will damage the ceramic seals in the pump - the warranty will be invalid on this installation. It may also just draw air in through the safety vent pipe. You will probably have to lower the shower head to start the pump.

If it does appear to run quietly then run it and monitor the water level in the cold tank - may need to use a mirror. It is possible to get higher flowing float valves or replace it with a 3/4 valve (if you can get a hole saw in to cut a bigger hole).


No guarantees with this setup though.

 

[gas4you]

As others have said, I was incorrect in the post I gave and it is best not to pursue this way forward.

Have you thought of fitting an electric shower?

 

[dholi]

As others have said, I was incorrect in the post I gave and it is best not to pursue this way forward.

Have you thought of fitting an electric shower?

did initially, but i have a very old property with severe electrical issues.
i invited an electrician to provide a quote and he made the job a million times bigger stating that i need a new CU before i go ahead with cabling in an electrical shower! this along with several other issues made the task of installing a shower a rather daunting process. hence the choice to install a pump...

 

[gas4you]

Look into gasguru's suggestion of a Trevi boost then.