Low water pressure

kah22

About five years back my heating and water system were upgraded and everything worked fine until about eight months ago.

I had two electric showers in the house; one dating back about twelve years and the other an electronic shower the type installed in disabled facilities. Anyway the old shower started to run either very hot, or cold. I put that down to age and thought nothing more about it, until about a month ago the newer shower just stopped sending out water. The old shower is upstairs the new one downstairs. I had my local plumber come out and have a look at them and I decided after talking to him to replace both units.

When they were installed neither produced hot water. The shower company replaced them but again they didn't work. When the service engineer called the second time he dismantled the unit and took a pressure from the feed pipe. It read about .9 bar. The downstairs shower

My local water board then came to check my outside pressure. Because my stopcock was a pretty old one they replaced it and took two pressure readings on different days, one read 3bar the second read 2.3 bar and that was just six inches from my house wall

Anyway when that was all done I again tried the shower, again no joy. What we did discover though was if you ran the shower and turned on another top or even flushed the loo the water from the shower almost stopped

The pressure taken from my cold water tap in the house reads a little over 1 bar but turn another tap on and it drops to about .5 bar.

Can anyone suggest what is going on here? It seems incredible that a water pressure of 2.3 bar just outside my back door drops to .5 bar once inside the house. Flow rate is 9 litres minute. The showers are gravity fed from the loft

Plumber90

Have you got anything on the pipework that may easily get clogged up, could be partially blocked and reducing the amount of water passing through

Ruski

If your showers are gravity fed from the loft then the incoming water pressure or flow rate have no bearing on your problem whatsoever

Are you SURE they are gravity fed?

HTH

Russ

Johnandabby

Is it just the showers that you have problems with? Flow rates through taps still the same as before?

It does sound like a blockage restricting flow, but you need to identify what outlets are still working fine to narrow down the search area.

As Ruski says, if you're feeding the showers from the loft you won't have great pressure anyway. But if the plumbing arrangement hasnt changed from before, then are the new showers suitable for low pressure systems? Did the previous models have a built in pump?

kah22

OK guys thanks for the feedback Ruski asks

Ruski wrote: »

If your showers are gravity fed from the loft then the incoming water pressure or flow rate have no bearing on your problem whatsoever

Are you SURE they are gravity fed?

Russ

OK maybe not to sure. The plumber told me that the water from the mains went up into the loft and then the pressure in the fall should be sufficent to run the shower. Especially the one down stairs. I was assuming that was gravity fed. Am I correct?

Needless to say I've been trying to do my own investigations because whatever the matter is I'm going to have to sort it out pronto. Anyway I came across this webpage and it was talking about something called a Salamander HomeBoost Pump but at around £360 not counting installation its pretty expensive.

One thought that occured to me was to get a plumber registered with the institute of plumbing and heating engineering. Again I really don't know that much about them and whether they are just plumbers who have joined an organization to show a few letters after their name.

I really would appreciate ideas.

kah22

Johnandabby wrote: »

Is it just the showers that you have problems with? Flow rates through taps still the same as before?

It does sound like a blockage restricting flow, but you need to identify what outlets are still working fine to narrow down the search area.

As Ruski says, if you're feeding the showers from the loft you won't have great pressure anyway. But if the plumbing arrangement hasnt changed from before, then are the new showers suitable for low pressure systems? Did the previous models have a built in pump?

Thanks for the comments.

I had thought of blockage myself but I don't think that's the problem for if I say turn on a mains tap one of the showers stops giving water completely, if I even flush the loo the pressure drops. At times I can put my hand to the kitchen tap and stop the water for a good minute.

As I said above the old shower, a Redring, was maybe twelve years old and it worked up till about 8 months back. The other shower, the kind that's installed in disabled facilities ran fine up till about two months ago and then just stopped, it was about seven years old. I'm assuming that if the supply was good enough up to about two months back it should be good enough now

kah22

A slightly different question so I'll make a different post.

I've been to see my local councillor this morning and he phoned the water company, explained the situation and they told him they'd be out within 48 hours and that they had to supply a consistent 2.5 bar pressure.

I'm wondering what is actually meant by CONSISTENT in this regards. Does it mean that if they take say three readings on three different days/times and the reading is say 2.7 bar is that consistent OR do they mean that if a mains tap e.g. the kitchen tap is running and it drops from 2.7 bar down to 2 bar is that what they mean by consistent?

As always thanks for your advice and imput.

Kevin

Johnandabby

I'm not sure where the minimum 2.5 bar comes from, the minimum is 1 bar at the supplier's stop valve.

uk_messer

As Ruski said, gravity fed showers/taps have nothing to do with your mains water pressure. Your water company are not at fault.

The pressure and flow rate is being created solely by your water tank it's height from the shower, and the diameter of the pipe from it. The lower anything is from the water tank you will have more pressure.

When you turn on more than one feed from the tank the pressure will lower from the first outlet- that's normal. Open a third and it will lower again.

What you need to know is what is the minimum pressure required for these electric showers to work. You say the engineer read 0.9 bar - but did he comment on whether that was acceptable or not? If it is, then it's up to the shower company to sort it. If it's not then you need to speak to your plumber. Typically 28mm pipe would be run from water tanks back in the day but some installs may have 22mm. Then there are bodge installs/repairs that could restrict flow. Damaged pipes also. Isolating valves (unless full bore) will restrict again. Go in the loft and check that the water tank is filling properly and also that the outlet is not full of crud.

uk_messer

Also, your kitchen cold tap should be being fed from the mains directly, not from the tank.

southcoastrgi

guys read the OP's posts
Kitchen sink will be on the main
Turn on kitchen sink = shower stops
Therefore shower is mains fed NOT tank fed

a blockage won't reduce your pressure at the outlets just the flow rate
check where the water comes in for a pressure reducing valve