Monobloc splashing

[rbel]

Is it a feature of all new monobloc tap/bathroom basin combinations that they splash water over the user even when the tap is only slightly open or am I just incredibly lucky?

-- rbel

[Brian Gaff]

ah, this is a feature. its meant to indicate that you need a flow reducing device i think. Its rather like those Hi Fi amplifiers that you only need the first 1 eigth of the travel of the volume control for it to be far too loud. You thus need speakers with very poor efficiency which require very special and expensive speaker wires to drive them.

Brian

[rbel]

Many thanks for the rapid response. As the problem occurs even when the tap is only slightly open is the splashing still down to the water flow or could it be the pressure? We now have mains pressure hot and cold water services.

-- rbel

[David WE Roberts]

You are very very special and water loves you.

Our Ikea basin and monobloc tap produce a fizzy stream of water which doesn't splash unduly. I assume there is a flow reducer in there somewhere because full flow thorough the shower does splash around.

Mains pressure water through a combi boiler.

Cheers

Dave R

[Chris Hogg]

A simple stop-tap further back up the pipe and turned right down helped ours, but I see you've got mains pressure on both H&C so you'd need one in each line. I also took the spray fitting out of the end of the tap, which helped a lot, especially as it was half blocked with plumber's mait.

[newshound]

Is the mains pressure particularly high? You could put a pressure reducer on this.

[polygonum]

Or an aerating nozzle? They were available in Lidl something like a week or two ago - £4.99 IIRC for a kit including a spanner and a few nozzles. You might find some left somewhere.

[rbel]

I have removed the grid fitting from inside the tap end but it has little impact.

Not as far as I am aware - being located at the highest point for miles around we are on a local pump boosted mains supply - the heating engineers who recently installed our boiler didn't comment on it. The flow rate is pretty average with a maximum of 18 l/min.

As the splashing occurs with the tap only slightly open it could be worth trying pressure reducers on both the cold mains supply to the bathroom and the hot water feed from the combi.

-- rbel

[harry]

Look under the sink. There will likely be an isolator vavle that you can throttle back the flow a bit and solve the problem.

[rbel]

There are service valves on the pipework but how would closing these a bit help? The problem is that the splashing still occurs when the monobloc is only slightly open - when the flow is down to a trickle.

-- rbel

[David WE Roberts]

In which case it is the design of the sink and monobloc which is causing the problem. Possibly a very tall tap and a very shallow sink? You could try putting a bowl inside the sink to see if a reduced drop and/or higher sides to the bowl reduce or eliminate the splashing.

I assume you bought the sink and tap as a set? Care to name and shame?

Cheers

Dave R

[rbel]

The basin is an Ideal Standard Jasper Morrison 55cm semi basin which has a quite reasonable interior depth of 155mm. The tap was not bought as part of a package with the basin.

tap is a Mayfair Wave mono basin with a spout height above basin top of 78mm giving an overall drop of 233mm. have just tried running the tap with a raised bowl in the basin and with basin 35mm or greater from the bottom of the basin the splashing stops. Unfortunately Mayfair do not do a significantly shorter monobloc in this range (and it matches the bath mixer) so it looks like a bit of a rethink.

Many thanks for the suggestion - a good bit of lateral thinking.

-- rbel

[rbel]

As a postscript I have spent a while looking at various tap retailers and manufacturers sites and it appears that modern basin monobloc taps with low spout outlets are few and far between. I could only locate a couple (not overly attractive) with a spout height of around 40mm so I reran the tests in the basin with the bowl at varying heights and concluded that a tap with a spout height of up to 50mm should solve the problem. At 50mm a quite smart Bristan monobloc, in the Quest range is available.

When replacing bathroom taps it seems that perhaps tap spout heights need to be taken into account, particularly as the current trend is for tall pillar monoblocs.

-- rbel

[David WE Roberts]

With our Ikea tap and basin the basin is about 100mm in depth and the spout of the monobloc is another 100mm above that - about 8 inches total drop in old money. The tap has some kind of frother device which gives a soft bubbly flow but it doesn't seem to splash even when on quite fast. So given your measurements, there is probably something more than tap height involved here. Could it be the tap spout angle, making the water hit something which causes it to bounce?

Cheers

Dave R

[rbel]

The tap spout is rectangular in cross section, 30mm wide x 9mm deep, giving a flat water pattern. It hits the basin on or just beyond the pop-up waste, depending on the amount the tap is open. Thinking about it could be a combination of the unusual water pattern and the length of the drop that is causing the splashing. The bath mixer filler has an identical spout and it also produces splashes but due to the depth of the bath they are not noticeable to anyone standing near it.

The potential Bristan replacement has a standard round nozzle so hopefully that will solve the problem.

I put a lot of thought into the spec of the bathroom but it did not occur to me that something as simple as tap design could result in problems, but there again I know absolutely zero about fluid dynamics!

I notice that the current vogue in designer taps is the open top 'waterfall' spout

would hazard a guess that they could well produce similar problems.

-- rbel

[David WE Roberts]

I would hazard a guess that they could well produce similar problems.

To my sordid mind that looks like something designed for washing your Hampton.

Also looks as though it would need a lot of cleaning in a hard water area.

Just checked again and our tap water hits the far side of the popup waste with no splashing. With the plug in the water bubbles and froths so it is a gentle aerated stream.

If handbasin designers do check for problems like undue splashing then presumably they do it with their own brand of taps, which may be an argument for getting a matching pair.

Then again I think most people choose their basins, baths and taps from seperate suppliers.

Cheers

Dave R