Plumbing : Boosting hot water to kitchen

[J-Tuner]

Hi All

Seeing as there has been a few plumbing threads recently i thought i would add to the list

My flat as a gravity fed hot and cold feed for the bathroom. The kitchen has a mains fed cold and a gravity fed hot for my mixer tap.The hot water pressure is dire and you have to turn the cold practically off to get warm water mixing. At present the mains in has been turned to 50% closed i think as its too much otherwise. This feeds the kitchen tap and the tank that feeds the bathroom.

Now i was looking for a cheap way to boost just the hot side of the mixer as everything else works fine as it is.

I was thinking i could purchase a single 1.2bar pump ( http://www.jcsbathrooms.com/12-bar-stuart-turner-s...) and plumb this under the sink on the hot water feed before the mixer tap. My friend said as the cold is mains (limited as mentioned above) it might damage the pump if it went back up the pipe to the pump. Therefore i was thinking i could fit a one-way check valve just after the pump to protect it from any feedback from the cold.

Would be a reasonable solution to my problem and not wreck a pump ?

Cheers !

Steve

Edited by J-Tuner on Tuesday 19th August 14:26

[convert]

Could you fit a service valve to the cold feed, and partially close it, thus reducing the flow to the cold tap?

[J-Tuner]

convert said:

Could you fit a service valve to the cold feed, and partially close it, thus reducing the flow to the cold tap?

No that wont work unfortunately. The mains is already at 50% closed via a tap/valve on the mains coming into the flat. If i reduce the cold any more i will just end up with a trickle of hot AND cold which is worse

[convert]

OK, How is the mixer tap connected to the hot supply? Does it use a flexi pipe? If so is this kinked?

What is the hot pressure like at other taps?

[J-Tuner]

convert said:

OK, How is the mixer tap connected to the hot supply? Does it use a flexi pipe? If so is this kinked?

What is the hot pressure like at other taps?

Ok the mixer tap has two flexi pipes coming out of it that connect into 15mm copper. No kinks anywhere at the tap. Hot water is provided from the cylinder so its gravity fed. The cylinder is stupidly at a low level (its on the floor of the flat) although it doesnt appear to be an issue in the bathroom suprisingly. It looks like its been like this since the flat was built. Above it is the cold water tank.

The Hot water pressure in the bathroom seem to be fine. The power shower is more than happy (in fact its too hot to be honest) and the bath and basin hot taps have a decent enough flow rate.

The kitchen tap on full open is a small flow, maybe fill a cup of water in 8-10 secs or so... its not great at all !

[HiRich]

I don't claim to be a plumber, but doesn't this suggest a problem with the kitchen spur?
You say a flat, so I presume the pressure head should be the same for kitchen and bathroom, being on the same floor (at least the kitchen is no worse than the bathroom).

• Is the run to the kitchen dramatically longer than that to the bathroom?
• Is the mixer tap knackered/blocked by debris? Perhaps you could try swapping the flexi pipes over and see whether hot improves and/or cold gets worse? Debris is quite a high probability.
• Has the copper pipe been crimped, deliberately or accidentally? A plumber kindly and unnecessarily decided to 'help' me by doing this in my kitchen, and I still can't find how.
• Is there a hidden service valve on the kitchen run? Perhaps hidden further behind the cabinets, perhaps closer to the tank end.

Ferg would give you better advice on a pump. My experience is that whilst effective, they are a bit of a pain and better fro when you really need it (bath or power shower)

[Busamav]

The run to the bathroom may be a larger dia.

It may also be that you have bought a european high pressure mixer tap for the kitchen , the actual final feed into the tap itself is likely to be 8mm

[J-Tuner]

HiRich said:

I don't claim to be a plumber, but doesn't this suggest a problem with the kitchen spur?
You say a flat, so I presume the pressure head should be the same for kitchen and bathroom, being on the same floor (at least the kitchen is no worse than the bathroom).

• Is the run to the kitchen dramatically longer than that to the bathroom?
• Is the mixer tap knackered/blocked by debris? Perhaps you could try swapping the flexi pipes over and see whether hot improves and/or cold gets worse? Debris is quite a high probability.
• Has the copper pipe been crimped, deliberately or accidentally? A plumber kindly and unnecessarily decided to 'help' me by doing this in my kitchen, and I still can't find how.
• Is there a hidden service valve on the kitchen run? Perhaps hidden further behind the cabinets, perhaps closer to the tank end.

Ferg would give you better advice on a pump. My experience is that whilst effective, they are a bit of a pain and better fro when you really need it (bath or power shower)

In answer to your questions mate :

• The bathroom is the room next to the cylinder cupboard. The kitchen is on another side of the cupboard. The kitchen sink is maybe 7-10ft away at the most. Its nearly centrally located in the flat
• The mixer tap is fairly new and the problem existing from day one. The previous taps were ste, and the hot flow was very poor back then also - hence replacing with this new one. Problem is exactly the same.
• Unsure if the pipe has a crimp - i would have to have a check and see on the entire run but what i see under the sink looks fine to me.
• I dont think there is anything hidden - the cupboard backs have no room behind them... i could try and look under the floor of the cupboards if pushed.

Cheers

Edited by J-Tuner on Tuesday 19th August 16:05

[J-Tuner]

Busamav said:

The run to the bathroom may be a larger dia.

It may also be that you have bought a european high pressure mixer tap for the kitchen , the actual final feed into the tap itself is likely to be 8mm

Unsure of pipe diameter from the cylinder to the kitchen sink but i highly suspect its 15mm all the way.

I do suspect that this new mixer tap is of european origin (germany ?) (as it does appear to taper in a bit just before the tap but its plumbed in right, and the problem existed before the tap went in. The taps cold pressure seems fine, and the hot is just the same as before...

[ALawson]

I had the same problem in my flat as the new taps I bought assumed that the system was pressurised. I swapped the hot and cold over and got acceptable performance, I think the internals in the cold side were bigger than the hot.

While we are talking about plumbing can anyone reccommend a electric hot water shower.