Can a shower pump work on any gravity-fed system?

[gerbils]

We're after a new boiler due to ours being inefficient. In an ideal world we would have a regular boiler + a shower pump but the 3 guys that came around didn't seem to like this idea.

1) Said we need a combi and confirmed our pressure is good.
2) Said we need a combi but could have a regular boiler if we really wanted, but each would require a mains booster pump
3) (came for a different job at the time) but said a shower pump wouldn't work (but didn't say why).

We have a standard gravity fed system with 2 big tanks in the loft and a standard 1985 glowworm MKIII in the utility room.

Close to getting a combi for the better shower pressure but concerned about leaks going from an open system to pressurised. Rads are a bit rusty.

 

[cross thread]

Shower pump will work if cold water tank is big enough and high enough ,if tank is lower a negative head pump may be required

 

[gerbils]

The cold water tank is pretty much directly above the 2 showers we have - maybe 2m away max. But in terms of height it's basically sitting on joists right above the shower so not very high.

 

[cross thread]

Negative head pump then,a lot more expensive than standard

 

[oldbutnotdead]

Your replies implied more than 1 shower? If mains dynamic pressure/flow is good you could look at unvented cylinders with yr new system or heat only boiler.
EDIT 2 simultaneous showers on a combi will be unimpressive.
Regarding efficiency, the cost of new boiler plus install will pay for many many less efficient running hours...

 

[Madrab]

but each would require a mains booster pump

Different from a shower pump, a mains booster pumps the cold mains coming in for the whole house.

Said we need a combi and confirmed our pressure is good.

Kind of negates the need for a mains booster, I presume what's being called the mains booster would actually be the shower pump?

Unfortunately the 3 guys may not know any better or have little or no experience with advanced hot water (HW) systems and only know how to throw combi's on the wall. Most gravity HW systems being fed from a large cistern (~ 50gal) in the loft can be pumped (cylinder dependent) but ideally both hot and cold would be pumped, it's just understanding what system is needed.

As suggested, a new boiler would take a long long long long time to recoup the install costs through better efficiency. Though it would be better for the planet.

 

[gerbils]

Different from a shower pump, a mains booster pumps the cold mains coming in for the whole house.

Kind of negates the need for a mains booster, I presume what's being called the mains booster would actually be the shower pump?

Unfortunately the 3 guys may not know any better or have little or no experience with advanced hot water (HW) systems and only know how to throw combi's on the wall. Most gravity HW systems being fed from a large cistern (~ 50gal) in the loft can be pumped (cylinder dependent) but ideally both hot and cold would be pumped, it's just understanding what system is needed.

As suggested, a new boiler would take a long long long long time to recoup the install costs through better efficiency. Though it would be better for the planet.

Thanks, yeah I may just get advice for a general pump and save the boiler for when it breaks.