How can I sense hot water flow?

[Rob Graham]

Our kitchen hot water tap is always getting left on because it is low flow and you cannot hear it running - and there is no point in shouting at the f amily because there is only two of us here and we are both guilty. And, ye s - I've shouted at her and I've shouted at myself- all to no avail.

So, I can do electronics and micro-processors and I thought there is a solu tion there, but putting a timer, a sensor on the hot water pipe and a bleep er is not going to work as the pipe will remain hot long after the tap has been put off - ditto doing that on the waste pipe. So I need a flow sensor to detect the tap has been shut off so that the bleeper doesn't start fals ely and to stop it immediately when it does do its duty. But is there some thing inexpensive that will do that ?

Thanks for any ideas. Rob

[The Natural Philosopher]

I THINK that a plastic pipe with a couple of electrodes inside and a permanent magnet will detect flow

the water becomes a basic generators

[tabbypurr]

w and you cannot hear it running - and there is no point in shouting at the family because there is only two of us here and we are both guilty. And, yes - I've shouted at her and I've shouted at myself- all to no avail.

lution there, but putting a timer, a sensor on the hot water pipe and a ble eper is not going to work as the pipe will remain hot long after the tap ha s been put off - ditto doing that on the waste pipe. So I need a flow sens or to detect the tap has been shut off so that the bleeper doesn't start fa lsely and to stop it immediately when it does do its duty. But is there so mething inexpensive that will do that ?

a flow switch?

NT

[Lee]

There are loads of cheap flow switches about, just a couple of examples.

Big Clive did a tear down of one similar to one of these if you want to search YouTube for it.

[Brian Gaff]

Motorised tap? Brian

[Brian Gaff]

I think such a low flow might be a bit of a challenge for most of the ones I've seen.

Brian

[MrCheerful]

get a concussive tap and adjust the shut off to a reasonable period

[GB]

If it's a stainless steel sink, remove the damping material from the bottom of the sink. Then you'll be able to hear the water hitting it? :)

[Harry Bloomfield]

Brian Gaff formulated the question :

A plastic paddle or propellor in the pipe, with a magnet moulded into the paddle and an Hall Effect sensor on the outside casing. You can buy them for pennies on Ebay. They work with very little flow volume.

[Andy Burns]

I'd noticed how cheap they were, was going to suggest them for the central heating status panel whoever suggested that a few weeks ago, rather than relying on the electrical head of 2 or 3 port valves, actually sense the flow to know if the valve has operated ....

[Adrian Caspersz]

Use an electrically operated water valve fitted under the sink and a push button. Press and hold for continuous stream, press 2 times to run until temperature warm enough, press 3 times for pre-measured amount to fill washing up bowl.

Actually, we need to do something like that for someone who is always leaving the gas rings burning away after cooking has been done.

[Harry Bloomfield]

Andy Burns formulated the question :

That was me - Installed and working fine, but needs a bit of interpretation to understand it.

[Rob Graham]

w and you cannot hear it running - and there is no point in shouting at the family because there is only two of us here and we are both guilty. And, yes - I've shouted at her and I've shouted at myself- all to no avail.

lution there, but putting a timer, a sensor on the hot water pipe and a ble eper is not going to work as the pipe will remain hot long after the tap ha s been put off - ditto doing that on the waste pipe. So I need a flow sens or to detect the tap has been shut off so that the bleeper doesn't start fa lsely and to stop it immediately when it does do its duty. But is there so mething inexpensive that will do that ?

Many thanks for all your replies, guys - as always helpful. And yes these sensors are cheap enough so I'll get one to play with though how I rig up a test bed that doesn't flood out the workbench is an interesting thought.

The problem is low head due to single storey cottage, a longish run and usi ng a mixer tap that is clearly designed for a high pressure system. The fl ow is therefore sluggish and silent.

Yes. I know there are a number of proper solutions to the problem, but they are a bit long term at the moment and not realistic in the winter, and thi s looks like a nice little project for the winter nights.

Rob

[Andy Burns]

A lateral suggestion while you acquire tuits to play with flow sensor, would sticking an aerator spout on the tap make it noisy enough to notice it had been left on?

[Vir Campestris]

How about a shower pump in the circuit? Gives you decent flow, and it's noisy enough to notice.

Andy

[0345.86.86.888]

Perhaps the best solution might be to change the tap for one more suited to low pressure.

That way you get a decent flow and reduce the chance of leaving it on.

Seems like you're trying to bodge a solution rather than fix the problem. :)