Shower pump question.

[xr4x4]

Hello all.

Quick question.

Is it possible to install a twin impeller pump level with the cold water tank?

 

[Breesey]

They normally require a 2m min head but I've seen them working perfectly well with as little as about 750mm. Bear in mind head is measured to the surface of the stored water.

 

[seco services]

They normally require a 2m min head

600mm is fine on most pumps.

 

[Breesey]

Yes, I should have said most installation manuals say 2m min head.

I think it's fair to say, as you effectively point out, that placing a pump on the same surface as the water supply would be fine.

 

[xr4x4]

We have a Stuart turner universal 3 bar twin, this requires 200mm min from water level to highest point on pipework in inlet....trouble is... We dont have this..so are now stuck, as we are struggling to find somewhere else to install the pump.

The inlet pressures so bad, I can put my thumb over the pipe and stop the flow!

Give me a aqualisa digital pumped unit anyday!!

 

[hazetimesfive]

universal pumps don't, they go anywhere.

 

[xr4x4]

universal pumps don't, they go anywhere.

They don't what?

I'm quoting the info in the manual.

 

[hazetimesfive]

We have a Stuart turner universal 3 bar twin, this requires 200mm min from water level to highest point on pipework in inlet

don't require this.

 

[hazetimesfive]

2.26 Non-preferred pump location: If it is not possible to locate the pump in the
preferred area due to site limitations and it is necessary to position the unit
in the loft, or in a position above the secondary tapping that feeds the pump,
then there is an increased risk of air locks. This risk must be eliminated.
The following measures are suggestions that may overcome the problem:
A “U” bend or downward loop in the supply pipe to the pump of 350 mm depth
before rising to the pump should ensure the cylinder vents its air up the
expansion pipe not up the pump feed

but even that is probably not necessary, once the pump is primed it shouldn't really have any problems, unless your boning the tank dry.

 

[xr4x4]

2.26 Non-preferred pump location: If it is not possible to locate the pump in the
preferred area due to site limitations and it is necessary to position the unit
in the loft, or in a position above the secondary tapping that feeds the pump,
then there is an increased risk of air locks. This risk must be eliminated.
The following measures are suggestions that may overcome the problem:
A “U” bend or downward loop in the supply pipe to the pump of 350 mm depth
before rising to the pump should ensure the cylinder vents its air up the
expansion pipe not up the pump feed

but even that is probably not necessary, once the pump is primed it shouldn't really have any problems, unless your boning the tank dry.

That doesn't list the point I was refereferring too.

I ment the head from the supply tank.

 

[hazetimesfive]

pardon me, must be the beer goggles..

still think it would work ok, they ask the earth for a warranty, but sometimes its just not practicable, i've probably changed more properly installed pumps than i have bodged ones.. strange how that works out.

I always worked it out that if there was a decent enough drop from the pump to the outlet then the neg pressure on the pump would be enough to solve any issues with lack of positive head on the inlet side, but I guess that doesn't effect you since you have a neg pump.

I would say go for it, unless you run the tank absolutely dry the water should stay inside the pipework loop that feeds the pump, I've done it on pos head pumps, 2 years still going strong.