domestic water booster pumps

What type of pump are you looking at? A domestic water booster pump? What's that then?

I've installed a few, but only to supply high flow rate pressure washers, so not a domestic environment. Having said that, they all worked a treat.

Machine Mart is the place to go, big selection.

We have a pump attached to a small pressure vessel which feeds the house. If the mains pressure is healthy the pump does not operate, but if pressure falls below a set level the pump starts and boosts the pressure. Turn the taps off and the pump pressurises the vessel again and then cuts off.

The pump has a max load of 500W, promises 40L/mimute at 15M head, and is self priming to 8M lift.

I'm sure I heard it called a 'hydroflor' but in this case google's not your friend. It came from a French DIY shed, Mr Bricolage.

You are not permitted to pump the incoming main directly. Where a pressure increase is required you have to use a header tank supplied by the mains and pump the output of that to feed the house, letting it recover slowly in between.

so far it's a pump (usually with pressure vessel attached) to boost my (spring fed) water supply up to the top of the house to supply a new shower room we're putting in. Current gravity arrangements have "done" for years but now not enough head to get water into loft tanks (for e.g) plus I want to add a filtering system which needs a good flow & pressure to backwash it- hence I need a pump etc.

jim

Hi keith - that sounds on the right lines - is it intrusively noisy when starting/running? Does it kick in every time water is used - or is there a chance to get a drink of water at midnight without waking everyone up for e.g.?!!

We have a spring fed system; gravity into filter and storage tank in garage. Switched pump through filter and UV purifier (and soon water softener) up into cisterns in loft. The pump is the one that came with the house so must be 30 years old and is switched with various float switches in the tanks. The head from the loft tanks is good enough for us without a booster pump.

I've used pumps with a pressure vessel and switch to provide decent pressure to outside taps and the best for that purpose was the Machine Mart CBM240E. Th electronic control system has a soft start, so the lights don't dim and the pressure changes as it switches on and off are less objectionable.

aha! that sounds almost exactly like the setup i want - except I'm thinking to do away with any high level tanks an d do hot water via a heatbank/thermal store (via heat exchanger).

Ah, right. I'll leave you all to it. :-)

Thanks for making that clearer for me.

Unfortunately my answers probably won't be too relevant to you, I'm in Bulgaria and although the pump's intended to boost the mains supply, mine's mounted at the top of a well shaft. When it kicks in the lights dim, but the electric supply is that poor the fridge has the same effect. When the town water supply drops I manually change over the gate valves to the well pump. From inside, directly above the shaft, the pump noise is quieter than the PC fan. On opening the tap you get an initial rush of higher pressure water, maybe half a litre or so, the pressure drops, then the pump kicks in and flow increases again. After the tap closes the pump runs on for a second or so. The tank is roughly the same size as a 25 litre calor gas cylinder, the pump's half that size, bolted on top and the whole thing's in an alloy frame with rubber feet. It would be simple to build a sound insulated enclosure, the power supply is a standard socket, so mounting in a basement, utility room, etc. would be easy and not too obtrusive.

Cheers

Keith, is your pressure vessel pumped up?

We used to have one at a club I was in, and when the vessel went flat that's just what it did. When the vessel was full you could get quite a bit of water before the pump came on. OTOH, sometimes you'd get a glassful and the pump would run for ages...

Jim, don't know the make. Sorry.

Andy

I've fitted a couple from Pump Express, like

The second installation I used a potable expansion vessel from Toolstation which was £30 instead of £40 Pump Express wanted.

They're remarkably reasonably priced for the specs.

There's a noticable drop in pressure until the pump kicks in again, which might be an issue if e.g. you're just pumping the HW to a non-thermostatic shower, but for a whole-house cold water pump it should be OK.

Also they're not the quietest things in the world so need to be installed carefully.

thanks to all so far - I have been told sketchy details (by a 'professional') about some special "flow controller" that apparently means an expansion/pressure vessel is not needed - does this ring any bells with anyone?

(it seems to me so far, that this would have to be rather special to detect small flows (or pressure drops) correctly and call the pump in time to recover and maintain an acceptable pressure?)

The noticeable pressure drop occurring when water is drawn and before the pump starts worries me a bit - is that something that is going to be hard to get away from? would a bigger pressure vessel help or just delay the inevitable "dip and surge" in pressure?

Thinking on - as the HW would be coming straight from the heat store heat exchanger fed by the the same pumped cold supply, I would hope that even non-thermostatic showers should not be *unbalanced* as the pressures of H & C should move together, (i.e. stay same relative to each other) - a bit of a dip and then a surge - does that sound reasonable?

all thoughts welcome thanks again Jim

The Machine Mart CBM240E that I mentioned earlier doesn't have an expansion vessel / pressure switch but has some sort of electronic controller. Although there is some pressure variation it's less than the expansion vessel / pressure switch types that I've used.

Seems reasonable to me.

Bill

hi Bill,

I checked with machinemart technical via email and they say *none* of their pumps come with a "soft start" setup... was it definitely from machinemart and definitely soft start?

many thanks Jim

I'm in the process of installing a log boiler with a rather large thermal store, so the hot water will be heated with a heat exchanger in the store rather than the current hot water cylinder.

I still want to use stored water in the loft though. It has the great advantage that you still have a water supply if you have a power cut. I'm hoping that the extra head loss due to the heat exchanger coils and the thermostatic mixing valve won't be too great; if they are I'll have to resort to a pumped system.

Bill

It definitely is the MM CBM240E. You're probably right, however, in operation it gives the impression of a less violent start than the standard pumps that I've used. It's probably imagination!

The manual gives the start/stop pressures as 1.6/4.8 bar which might give you an indication of the sort of pressure changes that you will get. I see the other small pumps with expansion vessel give 2/3.5 bar as the switching points which would imply less pressure variation than the electronic one. The other pumps that I've used weren't from Machine Mart so may have had greater switching hysteresis.

Bill

sounds interesting too! - I plan to install a bypass around the low level tank, pump etc etc to hopefully leave us where we are now, pressure wise- should it be essential to fill a kettle during a prolonged power cut - thinking further I might just have a tap on the incoming supply (from hillside tank) to enable cold sypply to fill a kettle

I can't think off hand of any bigger emergency requirements that may justify a full-on bypass setup??

Who is doing your heat store? I'm seriously looking at DPS -

Jim