High pressure hot water tank or whole of house pump?

[Boynielaad]

I've had conflicting advice re the above. I want to increase the hot water pressure through out the house.

First two plumbers have said whole of house pump will work whilst a third says the pump will just send the hot water to my expansion tank in the loft so I'll need the high pressure tank.

Who do I believe?

 

[Agile]

They have seen your installation! We have not!

Could you describe your installation in detail including the size of HW cylinder and the number of HW outlets and how many you expect to be useable at the same time.

Then we will have a chance of being able to advise you.

Has anyone measured the dynamic mains water flow rate?

Tony

 

[Boynielaad]

Not too hot on much of this but here goes:

4 bed house. Bathroom, en-suite with shower, kitchen, utility and downstairs toilet. Probably no more than 1 in use at any time.

Glowworm 18hxi boiler in the kitchen feeding hot water tank on 1st floor. Cold water tank in loft.

Hot water tank is about 3 ft high and just under 2 ft across. No idea on capacity.

The mains pressure is deemed to be good. No figures.

Hope that suffices.

 

[Agile]

Others may have something to say.

I will say that a twin shower pump could supply everything but not everyone would want to do that ( I dont know why but its not often done! ).

They do make a noise though and would usually be best sited close to the HW cylinder! Best supplied from a "flange" on the cylinder. Cost perhaps £400-£800.

Its not obvious to me what you want to achieve so perhaps you could explain?

Fitting a mains pressured unvented cylinder would be very good but would need figures on the flow to confirm its feesible. Cost about £900-£1500.

Tony

 

[besenzig]

Others may have something to say.

I will say that a twin shower pump could supply everything but not everyone would want to do that ( I dont know why but its not often done! ).

They do make a noise though and would usually be best sited close to the HW cylinder! Best supplied from a "flange" on the cylinder. Cost perhaps £400-£800.

Its not obvious to me what you want to achieve so perhaps you could explain?

Fitting a mains pressured unvented cylinder would be very good but would need figures on the flow to confirm its feesible. Cost about £900-£1500.

Tony

I'm faced with the same scenario. My conclusion is if you fit a pressuried cyclinder like a Megaflo for example the safety devices will need to be checked by a qualified by an engineer with 'unvented ' qualifications. This is an ongoing additional cost year after year.

A vented system with a pump quality pump (Stuart Turner) + Essex flange will work equally well and does not need annual maintenance. The results are the same and the system is much simpler to install and making use of the tank you've got....This is the route I will take unless someone can convince me otherwise. The only unvented portion in the system I would consider having 'unvented' is the CH.

Jod done, money saved

 

[Agile]

I'm faced with the same scenario. My conclusion is if you fit a pressuried cyclinder like a Megaflo for example the safety devices will need to be checked by a qualified by an engineer with 'unvented ' qualifications. This is an ongoing additional cost year after year.

If its combined with a boiler service this is unlikely to cost more than about £35 extra.

The advantage of an unvented is that they are very quiet compared with a pump which are very noisy.

Their performance is usually much better.

I find shower pumps to be very unreliable and I dont usually get involved in fitting them.

Tony

 

[Boynielaad]

The main reason for increasing the pressure is so that we can have a mixer shower in the bathroom at a later date. We currently have one of those taps with a hose coming off it (looks a bit like an old fashioned telephone).

It is virtually impossible to use the hose attachment as the cold water pressure is so much higher than the hot.

We also want to have a more powerful shower in the en suite.

His comment that a pump would simply push the hot water straight to the expansion tank has me worried. Could this be due to the layout of the pipes or is he wrong?

 

[Agile]

Properly connected there should be no problem.

Your problem is that the cold is mains pressurised and that means the hot and cold are unbalanced.

Depending on the actual mains pressure and the stability of that pressure it MIGHT be possible to just pump the hot only.

Just to make the shower more manageable you could have a pressure reducing valve on each feed to the shower so that they are balanced.

Tony