help needed please hot water pressure very low

[paulh7]

hello could someone give me some advice please
i have just installed new sink taps kitchen
and new basin taps for bathroom for a cousin
they live on a ( chalet site )
the cold water pressure is very good so good i have only turned a little on
but the hot water taps are very poor the water trickles out !
so i drained the tank in the hope it was clogged up in some way
left all taps open as i filled the tank back up so no air traps
after all that the pressure is the same very poor
they have a gravity system
they told me that it has always been like that 10 years
i told them i have never soon such a thing
been chatting to neighbors they systems are fine
thanks Paul

 

[gasmanrob]

So hw is gravity fed, just to rule out any cross reference or language barriers we are referring to a system whereby a cold water cistern located in the roof space feeds a cylinder where the water is heated which is then distributed to the taps?

(Sorry you'd be amazed how many people get confused)

Have you installed the taps on narrow gauge flexible hoses? Or taps designed for high pressure?

Or are we talking about standard pillar taps?

Also is the gate valve to the cylinder from the storage cistern located above fully open? By fully open I mean 12 or so turns from the closed position to a point it stops, if it continually rotates with no stopping point then I'd suggest this has snapped and requires investigation.

Also check storage cistern for debris as this could be blocking the outlet and starving the supply. And again if the cistern isn't covered is it possible loft insulation has fallen in and been pulled down the cold feed I've had that before.

Equally is it just a lack of head pressure and naturally poor flow, whilst the neighbours are actually on mains fed combination systems?

 

[paulh7]

thank you gasmanrob
good to speak to someone who knows about this issue
the taps I replaced looked 20 + years old !!!
I just replaced them with standard taps bought from Wickes £30 pillar one with long neck !
all taps have a 15mm copper pipe to them
I have installed isolation /stop vales now on all pipework
but was told the hot water was like that before I installed these valves
they have a copper cylinder tank in the cupboard with the header tank above
just to check if this is right the gate valve is on a 15mm pipe should it be 22mm ?
would it be wise to replace that gate valve
also should it be a full boa type ?
thank you Paul

 

[jtsplumbing]

Photo if possible ! are you saying that the supply to the hot water tank is in 15mm pipe ? (from storage tank to cylinder)

 

[gasmanrob]

The supply and out let should be in 22

 

[paulh7]

thanks again for replying
supply from header tank is 22mm and outlet is 22mm
the gate valve is on the 15mm pipe coming from the copper cylinder
the valve you turn off to stop hot water coming out of taps
also the hot water from cylinder tank is less than 8ft from all hot taps being a chalet
if this is of any help to you
thanks again Paul

 

[jtsplumbing]

thanks again for replying
supply from header tank is 22mm and outlet is 22mm
the gate valve is on the 15mm pipe coming from the copper cylinder
the valve you turn off to stop hot water coming out of taps
also the hot water from cylinder tank is less than 8ft from all hot taps being a chalet
if this is of any help to you
thanks again Paul

The outlet from top of copper cylinder should be 22mm, teeing off to go to taps and up into roof space for open vent over expansion tank, where is this 15mm gate valve ?? are you saying that the pipe of the top of the cylinder reduces to 15mm ??

Remove this valve , you should have a 22mm one on the supply into the cylinder that turns off supply to cylinder/hot taps,

A couple of photos would help

 

[stevetheplumber]

probably taps are for high presure and you have low on the hot side have you fitted a mixer tap ?if so main is overpowering the hot you need a biflow mixer

 

[JCSPLUMBING]

Your thinking of your heating side

 

[paulh7]

thanks for all reply's
I`ll pop back on Monday and take a few photos
no mixer taps
so please pop back on see the photo's
thanks paul

 

[stussy]

It really depends how poor the pressure is, but am I the only one thinking this is an air lock?

 

[kay-jay]

When you say 'chalet' is it a one floor setup like a flat?

Basically if the cylinder is on the same floor as everyrhing else and the header tank is on a shelf above it and not in a high point in a loft then thw 'head' will always be insufficient and the pressure poor

 

[jtsplumbing]

Just a thought, but are these header tanks in loft space ? or is it just a small one above cylinder ? Do you know what a combination cylinder (Fortic) looks like ? Has cylinder got its own water supply with ball valve in top section ? if so then you will never change water delivery rate to taps.

 

[kay-jay]

Just a thought, but are these header tanks in loft space ? or is it just a small one above cylinder ? Do you know what a combination cylinder (Fortic) looks like ? Has cylinder got its own water supply with ball valve in top section ? if so then you will never change water delivery rate to taps.

Yes you can. Raising a fortic will increase the head

 

[paulh7]

surely you would not get a air block if all taps are open when refilling the system !
thanks paul

 

[Best]

surely you would not get a air block if all taps are open when refilling the system !
thanks paul

Yes, you can. Leaving taps open won't usually prevent air locks. The fact that you drain pipes more or less of water means there is air in them. Problem is water in front of the air. Pipes can often be fitted too level or high spots also. Normally if you have an airlock that allows half flow of taps, then it will clear itself eventually- especially on hot pipes

 

[paulh7]

hello hope these photos help
thanks Paul

P.S pic 1 pipe to the left 15mm one going to header tank which I connected a stop valve
to the right of it is the other 15mm pipe going into the cylinder tank which has the gate valve on it 15mm
pic 3 two pipes 22mm going into boiler from the cylinder tank
I do hope this will be helpful to you all
thanks Paul

 

[kay-jay]

Quite frankly I think that poor pressure is the least of your worries.....

If the chalet is like a flat all on one level then you will never avhieve a decent flow at the taps without a booster pump.

 

[paulh7]

hello photo 5

 

[kay-jay]

hello photo 5
View attachment 22464

Your point is what exactly?

 

[jtsplumbing]

Is the boiler only heating the hot water ? or do you have heating as well ? need to be thinking about a multi-point or combi boiler.

 

[paulh7]

hello
and yes
the boiler is for the hot water and central heating
also in the photo what about that 15mm gate valve should it be 15mm
thanks Paul

 

[kay-jay]

hello
and yes
the boiler is for the hot water and central heating
also in the photo what about that 15mm gate valve should it be 15mm
thanks Paul

the pipe is 15mm therefore the gate valve has to be 15mm.

I am getting fed up of stating that the pressure will never get any better with that system if the property is all one one level like a flat.

You seem incapable of confirming this and are fixated on things that have very little to do with the problem you have.

Quite simply, and for the last time if the chalet is a flat like set up then you will never increase the pressure without a booster pump.

 

[JCSPLUMBING]

a booster pump would drain that small header tank in no time. A complete new system would be better (ie unvented or combi boiler) if the funds and cold mains flow rate/pressure allow

 

[Boilerbud]

Just check that cold is also gravity supplied because if cold connected to mains water supply the pressure will be far better than gravity hot water