mixer tap weak hot water?

[bobdabuilda]

You haven't said if your cold feed to the tap is from the mains or from a tank in the loft.... If its mains fed then you will end up with the back pressure filling your cold water tank and overflowing out the back/side/front(ie wherever your overflow pipe is situated!) if its left on long enough.

 

[marcopolo]

Not wanting to hijack tomii post but i have a similar problem. If you answer mine it may help him too.
Got house this week, mixer tap fitted, same symptoms.
Hot water good flow thru' tap (as is cold) (from a loft tank) Pull plunger for mixer, hot goes away and if i turn down the cold to get it warm it results in a dribble from the shower.
What to do?
Cheers

 

[marcopolo]

Anyone, Bueller, Anyone?

 

[guinness76]

Tap- Some mixer taps come with an alternative nossle for low pressure that connects to very end of tap, sometimes called an airator, to give a better output/ flow out of tap. Similar to putting finger over hose slightly. You unscrew nossle on tap carefully and change insert. Contact Hansgrohe technical help or cust serv. If not pump hot or 2 separate pillar taps.
Shower mixer- You need to reduce the cold pressure with a pressure reducing valve probably down to 1bar-ish, lots of different types, roughly £20 or less. Go to good plumbers merchant. Do bath taps below have decent pressure? You also might need to add a shower pump to hot. These mixer valves are great if your pressure between hot and cold are well balanced as all they do is mix, but if your cold water pressure is basically bullying your hot water then your more than likely going to get a cold shower.

 

[marcopolo]

Cheers Guinness
Might be looking at getting someone in to change our behind the gas fire heater to a Baxi type one in the kitchen someplace. So dont really wanna do anything too expensive, im sure i will need a lot of money for that eh.
Would dropping a 22mm onto the hot help?
Plumbing eh Electrics it aint!

 

[tomii]

Thanks Guys! been of most help so far, I'm all too new to this and thought it was a good idea to have the convenience of a mixer rather than two separate taps (as hot tap water is always too hot to the touch). From what I can work out the cold is from the mains I guess thats why the pressure is pretty good, but the hot water is from gravity. I have an electric shower which only use the cold mains which is adequate. I will still double check the mixer again like what Dal suggested, but I think installing a pump is the only way if that works. My problem with this approach now is should I go for a single or twin impeller pump. I have been trying to do some research on this, but still rather confuse. Cheers!!

 

[tomii]

Seems like I will only need a single impeller pump as can't fit pump on cold water mains. Anyway, another question is dose anyone know what is the difference between a Positive and Negative pump? also I think I have what is known as a fortic tank, would this hold enough water capacity for the pump?

 

[corgiman]

Seems like I will only need a single impeller pump as can't fit pump on cold water mains. Anyway, another question is dose anyone know what is the difference between a Positive and Negative pump? also I think I have what is known as a fortic tank, would this hold enough water capacity for the pump?

if you have a fortec cylinder you really should replace the tap as I find pumping this to be a pain in the arris

but if you insist on keeping your inappropriate tap (BTW they do do low pressure kitchen mixers!) then it should work

 

[tomii]

Thanks corgiman, I have no choice as I have already purchased and installed the mixer and basin which cannot be returned now. My main concern is someone told me that if I had less than 40gal on my fortec tank then I can't use the pump, is this correct? also should i use a postive or negative pump? thanks

 

[corgiman]

Thanks corgiman, I have no choice as I have already purchased and installed the mixer and basin which cannot be returned now. My main concern is someone told me that if I had less than 40gal on my fortec tank then I can't use the pump, is this correct? also should i use a postive or negative pump? thanks

only if the sink is above the tank will you need a negative head pump

 

[bobdabuilda]

tomii- has your overflow been pouring yet?

 

[tomii]

Sorry, what do you mean my overflow pouring?

At present I'm still stuck with this problem and am unsure about the pump solution as my fortic tank might not have enough capacity for the pump. I may have to give up and call in a plumber....

 

[JohnD]

or you could fit another pair of single taps and get good flow at less cost.

still true

 

[tomii]

Yes, I could but I have already purchased this expensive mixer and can't return it. Can anyone tell me what is the difference between a unvented and a vented hot water system? trying to find out what my one is classified as. Thanks again.