Technical Problem In-line Pump for Hot Water

[Roadtiger]

Hi guys,

I'm new to this forum.

I have changed my basin separate tap to a mixer tap. There was a low pressure on hot water side and thus, after deciding on different things, I decided to put in line a pump to boost the pressure. Yes, it worked but not every working is pleasant enough.

Now, I have high pressure hot water but as soon as I open the cold water valve/tap to have a warm mix, the pump stops working. So, again, I either have very hot water only or very cold water only. It seems the problem was spinning around that £100 spent on the work.

Does anyone know how I can stop the pump from stalling when cold water is on?

Thanks in advance.

 

[Newboy]

It sounds like the cold water is backflowing into the hot water pipework. Is the cold supply mains fed?

If this is what's happening then you need balanced supplies - same pressure for both H&C or alternatively, a tap with separate channels for H&C.

Do you know what the cold water pressure is ?
What pump have you fitted?

 

[Roadtiger]

Yes, you're right. The cold water backflows in the hot water pipe. Cold water is fed from mains.

I searched for a separate channel taps but couldn't find any. What's the key word? Could you please share a web site or something?

I don't know the pressure of the mains, as I don't have any device to measure it.

The pump is a Salamander CT55+ Single.

Thanks for your help.

 

[Newboy]

I'd try a known brand and give the helpline a call to ensure that any product you select can do the job

example

http://www.bristan.com/epages/Bristan.sf/en_GB/?ObjectPath=/Shops/Bristan/Categories/Taps

 

[xr4x4]

Or just fit a non return valve on the hot and cold.

 

[Newboy]

Probably still won't work - if the hot water feed pressure is too low then the NRV won't help as the hot still won't overcome the cold feed pressure

 

[blackfriars]

hi roadtiger

this item will work for you , it will allow you to have equal pressure
it equals the pressure of both supplies to a constant and there is no backflow

WATER PRESSURE EQUALISING VALVE

Equalises hot and cold water pressure by automatically adjusting the higher water pressure to balance with the lower. Easy to install and ideal for shower mixers, bath/shower mixers, single lever mixers, bidet mixers. The mixer must be designed to operate on equal pressure. The valve will equalize pressure on multi-point/combi or fully modulating gas boilers, gravity systems, mains pressure hot water cylinders, or any hot water system which provides constant temperature output.

DIMENSIONS :
L 100 x W 75 x D 60 mm.
Thread : 1/2" BSP Male on all inlets and outlets.
Nuts and olives not supplied.
Working pressures :
minimum 20 kPa, 0.2 bar (3 p.s.i.)
maximum 1,000 kPa, 10 bar (150 p.s.i.)

For nuts P/N 6744 and olives please click here. www.bes.co.uk
Part No. Description Unit Price Qty
16711 Water pressure equalising valve £46.25

 

[blackfriars]