Non-Concussive Taps??

Pross

We've got a leaking tap in the office and the plumber has just come in to look at it. He says he has changed the washer but that it will still drip as it's a non-concussive tap and designed to drip when the heating is on. This sounds like BS to me (knowing nothing about DIY or plumbing) so can someone confirm if it is true? It seems odd that a tap should be designed to drip constantly!

sungod

he's spouting utter nonsense, the issue here is clearly non-competent plumber

bianchimoon

Sounds like your plumbers got concussion

veronese68

If t will still leak why did he bother changing the washer? Presumably it didn't leak previously, I too call BS.

MountainMonster

A quick Google of the term leads me to believe they shouldn't drip. Another way of explaining non-concussive taps is apparently self closing one. They are sold as water saving technologies, so again, they shouldn't drip.

Sounds like he's simply too lazy to do any real work.

Pross

Seems to back up what we are all thinking too. I guess we can see what happens when the heating is off!

Phil Fouracre

Oh, for crying out loud! He must be stupid, comments are correct, it should not leak, yes it's a water 'saving' device. And whatever the heating is doing will make no bloody difference whatsoever.

veronese68

Is that what they are. We have that sort of thing here, they don't leak regardless of what the heating is doing. They do occasionally stick on and not turn off though. Our plumber said it was because they were dirty.
From these feeble excuses I can only surmise that they are not very good and prone to problems so the plumbers resort to BS to get out of having to come back.

Pross

It'll be interesting to see how much he bills our landlord for changing a washer and not fixing the problem. No wonder he was available to come out at such short notice That said, despite his comment the tap doesn't actually appear to be dripping now :?

reds99

At work weve got a similar situ. Theres a note regards the hot water tap:" do not over tighten, this tap will drip as its self venting" or words to that effect

pinno

Is it the hot tap or the cold tap?

Some heating systems are pressurised. If it is the hot tap leaking when the heating is on, this could be because of a build up of pressure. This is not a healthy situation which needs to be looked at. Some pressurised heating systems or where there are more than 1 boiler/immersion heater utilise a 'Neutraliser'. Put simply, these alleviate pressure by balancing the differences in temperature and heat etc.
If your system has a Neutraliser but it is clogged up (because of limescale, oxidised metal, debris, poor water quality) the pressure build up will cause problems. Until this is sorted, take comfort in the fact the tap is leaking.
There are other causes of pressure build up but the fact is, either way, hot or cold tap, it is bollox.

http://www.dunsleyheat.co.uk/LINKUP_LEAFLET.pdf.

desweller

pinarello001 wrote:

Is it the hot tap or the cold tap?

Some heating systems are pressurised. If it is the hot tap leaking when the heating is on, this could be because of a build up of pressure. This is not a healthy situation which needs to be looked at. Some pressurised heating systems or where there are more than 1 boiler/immersion heater utilise a 'Neutraliser'. Put simply, these alleviate pressure by balancing the differences in temperature and heat etc.
If your system has a Neutraliser but it is clogged up (because of limescale, oxidised metal, debris, poor water quality) the pressure build up will cause problems. Until this is sorted, take comfort in the fact the tap is leaking.
There are other causes of pressure build up but the fact is, either way, hot or cold tap, it is bollox.

http://www.dunsleyheat.co.uk/LINKUP_LEAFLET.pdf.

I don't understand. I thought the vast majority of hot water supplies derived their pressure either from a gravity head or the mains pressure?

Semantik

Point of use or oversink hot water heaters used for handwashing in factories,workplaces etc. are often DESIGNED TO DRIP when the water inside the storage vessel is being heated(unless they have a separate expansion vessel) -the stored water is kept heated with the help of a thermostat so hot water is always available at a more or less constant temperature at the draw off point(i.e. tap)
See here:
http://www.hyco.co.uk/product.asp?id=270
The product description explains that it is normal for the outlet spout to drip!

Something may have been lost in translation of what the plumber said: 'when the heating is on' is a vague term at best. But it is true to say that taps will never drip simply because your central heating system is in operation, despite what one of the posters above seems to think. And if the plumber actually said this then, yes, he is a clown.

Pross

Yep, it's what he said. The boiler is in a separate room about 10m away.

bernithebiker

All immersion tanks must be fitted with a relief valve / tap to prevent potential explosion of the tank when the water is heated.

This valve can be seen dripping as the water heats up.

pinno

bernithebiker wrote:

All immersion tanks must be fitted with a relief valve / tap to prevent potential explosion of the tank when the water is heated.

This valve can be seen dripping as the water heats up.

Thank you. A relief valve or 'neutraliser' valve.

desweller

Why would the pressure not be equalised with the incoming mains pressure?

bernithebiker

DesWeller wrote:

Why would the pressure not be equalised with the incoming mains pressure?

I believe, because most mains inlets have a non-return valve in them to prevent household water returning to the mains. So it is in fact a one-way system.

desweller

Is there a reason the PRV could not be connected to the incoming supply? I.e. as a check valve in the opposite direction.