Can Anything Be Done

[jennyjoan]

I have a hot water tap (kitchen) which is just more than a trickle so when it is too hot I turn the cold water tap to mix - however the cold water overwhelms the hot tap and I can't get even luke warm water.

Could a plumber sort this. thanks

[Old_Geezer]

You need the plumber to tell you why the flow is so weak and whether it can be fixed. The solution will depend on your system.

[The Builder]

A very common problem JJ, when the wrong type of tap is used.
I guess you have a gravity hot water system (immersion cylinder in cupboard?)
The cold will be from the mains, hence overpowering the hot.

These mixers can restrict (strangle) the hot supply. Apart from replacing the tap, all I can suggest is either an electric pump on the hot supply (could be some expensive faffing about),

or .... get a plumber to fit a water pressure reducer to the cold supply.

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[vulcan42]

The Builder, would turning the inlet tap down a bit (very technical description) help?

[The Builder]

Vulcan...

I guess you mean the incoming main stopcock?

That's what a lot of people do. It's rather hit and miss, and rarely solves the problem. Doing that, not only restricts the pressure, but can severely reduce the flowrate as well.
Reducing flowrate affects the whole house, resulting in problems of enough supply when more that one tap is opened at the same time.

Pressure reducers just reduce the pressure....... not the flowrate :o)

[vulcan42]

The Builder, thank you, I'll stick to the woodworking!!

[The Builder]

My favourite too, Vulcan :o))))

[hereIam]

I have this problem too. I had a new kitchen fitted just over two years ago with mixer taps and while it was just more than a trickle before, it seems even worse now! Interesting to note it's because I have an immersion heater. I have thought about getting a plumber out, but manage by boiling the kettle if I need really hot water.

[The Builder]

Yep, hereiam, as I said above, a very common problem, caused by pressure imbalance.

Supply to taps is 15mm pipework. Modern mixer taps have braided connecting tails that can have as little as 8 or 10 mm diameters. That's where things go wrong with a gravity system.

Another cause may be the use of "ball-o-fix" servicing valves fitted under the sink. ( you know the ones ... either a handle or a screwdriver slot.)
These also strangle hot supplies greatly.

[The Builder]

Seriously, to hereiam and JJ both....

I would consider returning to the "old days", and replacing the mixer tap with two separate taps. The trouble is, mixing is so convenient.

Alternatively, replace the mixer with one that is capable of handling a very low pressure. Mixer specifications usually give this information. It'll say something like "suitable for gravity systems".

Even then, reducing cold pressure is still needed to restore "balance".

[bhg481]

hereiam - I can see no reason why having an immersion heater should restrict your water flow. I think the builder only mentioned immersion heater as an easy way of defining whether you had a gravity-fed system or a combi-boiler. From my understanding, combi boilers have the water under pressure whereas gravity-fed systems just use the height of the loft tank to provide the hot water pressure.

I wonder if the hot water stop-valve in JJ's airing cupboard is not fully turned on.

[jennyjoan]

thanks all for your answers - I will leave well alone cos I don't understand plumbing. When my nephew is well I will get him to look at it again.

[jennyjoan]

Builder - I don't think I could get the separate taps as like HIA - I only got the new sink (Blanco) last year and there is just one hole in it for the mixer taps.

[The Builder]

Good point JJ. Single taphole-

for bhg.......

No, I didn't say a gravity system can restrict flow.
But, as you say, it relies solely on gravity for pressure. What I was getting at is the restricting nature of braided tap tails, modern mixers, and/or servicing valves.

When you have a low (gravity) pressure to start with, restricting the hot, and combining with mains pressure cold, just makes for mixing problems.

I assumed JJ has this system. If she had a combi, then the problem couldn't arise in the first place. :o)

[bhg481]

The Builder - thats what I was trying to explain to hereiam, who assumed that the immersion heater would cause pressure loss. You wouldn't normally have a combi-boiler AND an immersion heater so, if you have an immersion heater your hot water pressure depends solely on the vertical distance between your tap and the header tank in the loft (less constrictions such as tap-tails etc).
Incidentally, I gave you an hour to explain to hereiam before I posted and then I assumed you had work to do, unlike this retired person.

[hereIam]

My hot water used to trickle before I had my new mixer taps though, but not as bad as it is now. I live alone, so I'm quite happy to boil a kettle whenever I want hot water quickly and I'm used to that now, so I probably won't get it fixed. I remember the last time I had the misfortune to get a plumber in, I was charged £270 to fix a problem in my water tank, afterwards a friend told me he could have done it for free with the necessary piece of equipment costing £6.70 in the shops (the plumber charged £55 for the said article!) and he made sure he went into a second hour to charge me more. Didn't look me in the eye once and never smiled! My beloved Dad was a plumber and he would have been horrified !

Thanks bhg and The Builder.

[Hopkirk]

Buy a plastic washing up bowl, and run hot then cold until you get water at the temperature you need.