New Granny Annexe, Hot Water and Power Shower

[Invisible-Man]

Hi,
I have just had a granny annexe built which consists of 1 bedroom with cupboard in corner (outside wall) to house a hot water cylinder/immersion (no gas to building), other side of cupboard (next room along outside wall) is the bathroom to include toilet, shower and hand basin, (further along same outside wall) is kitchenette/front room.
I have fitted a 50 gallon cold water tank in the loft above bathroom, height above ceiling joists approx 5".

The water main is good and enters the building at the bathroom.
I was wondering if I could use the mains water for all cold, to include taps, cistern, cold tank supply including power shower (using pump only for hot)?
If shower pump (maybe situated under hot water cylinder) is ok to supply hot water only from cylinder, is it ok supply all hot water, not just the power shower.

The reason I ask about pump supplying all hot water is that I was going to run hot supply from cylinder back up into the loft, then down into the bathroom/kitchen as easier to route, also without the cold coming through the pump aswell would save a hell of alot of pipes coming up and down into the cupboard from loft, plus having only 1 hot feed for shower and taps would save pipework up and down loft.

Hope this makes some sense, and would welcome any other idea's for a different setup (electric shower not an option due to power consumption)

Many thanks!

 

[ChrisR]

SOunds fine to me. A pressure equalising valve on the shower supply would give any mixer an easier time - check yer differentials on the mixer input spec.

 

[bster]

ChrisR -

Is it allright then to use pumped hot and mains cold for a power shower I thought pump both for a more balanced supply?

 

[Lee-King]

I'd install a Salamander whole house pump, you have 50 gallons of water which is a minimum requirement for one bathroom. 50 gallons of water just to feed your cylinder isn't really needed so you might aswell utilise the amount of stored water you have.

 

[Invisible-Man]

Thanks everyone, just a couple of things:

Obviously the cold mains is standard to run all in 15mm, but if all the hot water is running through a pump at what point would it be ok to reduce down to 15mm (before pump, straight after pump, or only reduce down to 15mm at each outlet)?

Also as all the hot water is through a pump, would the standard outlet from the hot water cylinder along with vent back up to cold tank be ok to feed the pump?

Can anyone recommend a suitable pump along with model number to suit this setup, I note the Salamander whole house pump as a recommendation (any particular model number)?

If I were to use an equaliser valve on shower as recommended, is this built in to the shower or is it a seperate purchased component?

Any recommended shower would be appreciated!

 

[Invisible-Man]

Anyone!