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Total Members Voted: 3

[chrisgixer]

Kitchen tap, will not flow hot water.

The system runs with a pump in the loft to boost pressure for the shower mostly, but its also been used to boost everything that's not mains fed. As the water flow is so poor.

So, the kitchen tap runs mains pressure on cold, and flows fine, as mains pressure is good. Hot however, refuses to give the initial flow the pump needs to see to strike up.

Tap is mono block with two 10mm bore pipes within. The plumber says its the tap, causing it due to the reduction in pipe size and lack of initial pressure from upstairs hot tank.


We've been cheating it to work by turning on the kitchen hot tap, then turning on the downstairs cold to get the pump to chime in. Once pump is running, the already open hot tap then flows.

How can we get the hot tap to flow normally?

[MR MISTER]

You need to move your storage tank onto the roof.

[Michael2.6]

You say you have a plumber

Why can he not fix the problem is it because of the price he has given you?

Is the boiler a combi or not

Oil or gas?

[SIR Philbutt]

It sounds like the tap needs to be on the pump's cold and not the mains. The pump needs to see both flows to start

hth
P

[zirk]

Sounds like air in the system to me, normally got rid of by opening downstair tap, opening an upstairs one nearest the tank that works then blocking it with a towel or something to force the air out to the others.

[Big_Al]

Chris, where is your pump in relation to your cold water tank ?

Pump needs to be a minimum of 1 metre below lowest point of the cold water tank .  Usual set up IMO is cold  tank on a stand in the loft & pump in bottom off airing cupboard . That should give a gravity head of 2.5 -3 metres  which should work fine 

Gravity hot water is dependant on the height of the cold header tank in the loft . The "head" between the hot tank & the cold tank is the critical factor . As long as the cold tank is in the loft , you can have the hot cylinder on the ground floor & hot water will still flow well to the upstairs  hot taps provided they are at least a meter or below the cold header tank .  .A pumped  Shower hot  should be fed off of a "surrey flange"  on the hot water outlet of hot tank, rest of hot water to house should be  direct from outlet of hot tank so should not be pumped 

Wot sort of plumber you using / . . . he sounds a bit " unsure" of himself 

HTH 

[05omegav6]

If a recent issue that was previously fine, then I suspect the flow switch on the pump is the culprit

Question is either if it is partially blocked or failing How old is the set up?

[chrisgixer]

You need to move your storage tank onto the roof.

Have wondered about that, hot water tank is on the landing. Cold water tank is in the loft.

[chrisgixer]

You say you have a plumber

Why can he not fix the problem is it because of the price he has given you?

Is the boiler a combi or not

Oil or gas?

Plumber suggests replacing the tap due to the restrictive bore.

We don't want to o this as its exactly the tap we want.

Combi couldn't keep up with a pump. The two are not comparable, so we have to have a hot water tank to feed said pump. As said this is on the landing.

Its gas.

[chrisgixer]

It sounds like the tap needs to be on the pump's cold and not the mains. The pump needs to see both flows to start

hth
P

Tap cold is on mains. Works fine. High pressure.

Tap hot is on pump from water tank on landing. The drop is barely a meter from the foot of the tank.

There is another hot tap in the downstairs loo. This runs ok, although that tap is furred up with lack of use. But it does flow. Just.

[chrisgixer]

Sounds like air in the system to me, normally got rid of by opening downstair tap, opening an upstairs one nearest the tank that works then blocking it with a towel or something to force the air out to the others.

It does splutter occasionally.

[chrisgixer]

Chris, where is your pump in relation to your cold water tank ?

Pump needs to be a minimum of 1 metre below lowest point of the cold water tank .  Usual set up IMO is cold  tank on a stand in the loft & pump in bottom off airing cupboard . That should give a gravity head of 2.5 -3 metres  which should work fine 

Gravity hot water is dependant on the height of the cold header tank in the loft . The "head" between the hot tank & the cold tank is the critical factor . As long as the cold tank is in the loft , you can have the hot cylinder on the ground floor & hot water will still flow well to the upstairs  hot taps provided they are at least a meter or below the cold header tank .  .A pumped  Shower hot  should be fed off of a "surrey flange"  on the hot water outlet of hot tank, rest of hot water to house should be  direct from outlet of hot tank so should not be pumped 

Wot sort of plumber you using / . . . he sounds a bit " unsure" of himself 

HTH 

He is a heating engineer. He installed the new boiler. And fitted a new central heating system in in a friends house. Seems knowledgable generally, if you can get hold of the bugger. Although he did ask advice on the tap itself, and it was then suggested to change the tap, as mono blocks are "renowned for it" he said.

May be, but there must be away round it surely...?

I'm tempted to fit a hose from the mains onto the the tap and blast vold water up it to clear any sir lock, but I'm not sure that's wise on a hot tap?

[chrisgixer]

If a recent issue that was previously fine, then I suspect the flow switch on the pump is the culprit

Question is either if it is partially blocked or failing How old is the set up?

Problem has been present since that tap was installed. But now we have the pump fitted it refuses to flow at all until the pump is activated by the turning on another tap elsewhere in the house.

[chrisgixer]

Here's the tap itself
http://www.tap-spares.com/sections.asp?id=48&sortit=3&pg=2

And here

http://www.howdens.com/media/library/pdf/108.pdf

[Big_Al]

You say you have a plumber

Why can he not fix the problem is it because of the price he has given you?

Is the boiler a combi or not

Oil or gas?

Plumber suggests replacing the tap due to the restrictive bore.

We don't want to o this as its exactly the tap we want.

Combi couldn't keep up with a pump. The two are not comparable, so we have to have a hot water tank to feed said pump. As said this is on the landing.

Its gas.

Absolute NO No  in my book  . . .  .you should never  use a pump on a combi boiler 

PM   sent  Chris