Low water pressure

[Old Account]

Hello all engineers


a customer of mine called me about low pressure and not mixing really hot water with cold water.

i have checked the mixer and mixer was faulty as the quater turn were gone ...

but it it didn't really help to increase cold water pressure neither the proper mixing.

i have check that all valves are fully open / loft has got only a cold water tank but all valves are fully open

filters are all clean , kitchen has got full pressure.


Problem is when you want to take a shower most of the time just roasting hot water even though I reduce the pressure of hot water ...

Hot water cylinder is also all fully open


do you think there is an air lock issue ?

opened pipework under bath not really good pressure ...

I I recon could be also a faulty valve which is stuck inside ?


Thanks a lot

 

[Stanios]

Sounds like the thermostatic cartridge inside the mixer is knackered. Straight forward to replace if you can get hold of a replacement..

 

[Old Account]

Sounds like the thermostatic cartridge inside the mixer is knackered. Straight forward to replace if you can get hold of a replacement..

I have changed the whole mixer today and again same issue I recon isn't the mixer it's the installation itself...it's very unlikely again that the mixer is gone too as I have changed it twice now ... Thinking of an different issue maybe stuck stop clock / washer not fully open even though I checked them all

 

[Ch4 plumbing]

Is it a bar mixer? Can you remove the valve and put a hose on the unions and then turn the supply back on? Soon tell you what the pressure and flow rate is like.

 

[Old Account]

Is it a bar mixer? Can you remove the valve and put a hose on the unions and then turn the supply back on? Soon tell you what the pressure and flow rate is like.

Thank you all for your help !!!


Attached you will find the picture f the bath mixer very simple one nothing special ...
Zippyshare.com - image.jpg

I can take the mixer off yes and have still unions sitting onto the bath ... Pressure is low on cold site and hot is pretty good ...

I am still thinking either a little blockage cold water tank ... Pipe ... Or air lock ... Stuck valve ..


One of those I assuming

 

[Stanios]

Thank you all for your help !!!


Attached you will find the picture f the bath mixer very simple one nothing special ...
Zippyshare.com - image.jpg

I can take the mixer off yes and have still unions sitting onto the bath ... Pressure is low on cold site and hot is pretty good ...

I am still thinking either a little blockage cold water tank ... Pipe ... Or air lock ... Stuck valve ..


One of those I assuming

Nice overflow

 

[Old Account]

Nice overflow

True !!!

During installing it's better to take it off if you do not have any space whatsoever

But thanks for the reminder

 

[Ch4 plumbing]

Assuming they are both gravity I would expect them to be similar pressure/flow, might be worth check the gate valve isn't stuck half way!

 

[Old Account]

Assuming they are both gravity I would expect them to be similar pressure/flow, might be worth check the gate valve isn't stuck half way!

They've got very old stopcock so in the loft I am not able to turn them I even tried using wd40 but no chance of turning them.

The owner told me they always had this issue since they moved in.

What do you recommend to do ?

Hot water is find but cold water in bathroom is low pressure ...

 

[Ch4 plumbing]

Isolate/Drain CWSC change any valves on the cold down service (might as well do the hot isolated while its drained) and hopefully that will sort it!

The cold down service is in 22mm yes? Not 15mm?

 

[Old Account]

Isolate/Drain CWSC change any valves on the cold down service (might as well do the hot isolated while its drained) and hopefully that will sort it!

The cold down service is in 22mm yes? Not 15mm?

As far as I remember from the big round cold water tank was the outlet 22 a little but then still in the loft reduced to 15mm .. Yeah that might the only solution ... What could be wrong to cause this issue only something which restricts the flow at the cold water side


Thanks dude for your help

 

[Ch4 plumbing]

If it's 15mm then that's your problem,naïf the cylinder feed is 22mm and the CWSC is 15mm that's why the flow rate is unequal.

 

[Old Account]

True I will check it today what sort of sizes I've got ... Thanks for your help anyway appreciate very much

 

[Old Account]

But the funny thing is cold water pressure at the basin was great .. I really don't know what the issue is ... All sizes are 22 mm so this is fine but still don't know why hot is good but pressure cold is low

 

[JCSPLUMBING]

The basin is probably mains pressure. Cold down sometimes only feeds the bath. Replace all gatevalves on cold down service with full bore levers. Also stick some solder down inside tank connector and give it a wiggle. May be a bit of scale lodged down there

 

[Old Account]

The basin is probably mains pressure. Cold down sometimes only feeds the bath. Replace all gatevalves on cold down service with full bore levers. Also stick some solder down inside tank connector and give it a wiggle. May be a bit of scale lodged down there

Thank you first of all for your help !!!

Believe it or not but the pipes are coming underneath the bath straight up and T's off to bath in 22mm and in 15mm to the basin so is not a from the street. Either valves are stuck or as you said something restricts the water flow in the fed pipe. I'm gonna change the valves and poke something through the fed pipe.

Thank you for all your help here appreciate it

 

[PlumbBobBob]

put your thumb over the cold tap spout and then open the tap, if you can hold the water back it is tank fed but if you get wet from higher pressure it will be mains fed.