Low Water Pressure in Joydens Wood and Bexley: Causes

Start with the cold tap in the kitchen. If that is weak too, ask a neighbour whether theirs is, and check Thames Water’s postcode map for work in your area; if the whole road is low, it is the network and Thames’s job. If only your house is affected, the usual culprits, cheapest first, are a stopcock that is not fully open, scale blocking aerators and shower heads, and a leak on your own supply pipe. A meter test sorts out the last one.

Why Joydens Wood gets it worse

Joydens Wood is on the hill above Bexley, mostly post-war bungalows and houses. Water has a long way to come up to reach the top, so pressure there is naturally lower than in Old Bexley village down by the Cray. Add sixty-year-old copper laid in concrete floors, a supply pipe under a front garden that has moved with the clay for decades, and hard water off the chalk, and you have several ways for the flow to drop without anything obviously being wrong.

Down in the village, the older houses around the High Street have a different version of the problem: original lead or iron supply pipes, some of them a century or more old.

Step one: is it just you?

Thames Water’s own advice is to try the cold kitchen tap first, because that comes straight off the mains. Then:

• Kitchen cold tap weak, neighbours weak too: probably a network issue. Look at Thames Water’s incident map by postcode, or report it online. Nothing for a plumber to do.
• Kitchen cold tap fine, but the shower and bathroom taps weak: the problem is inside the house. Often a loft tank system, a part-closed valve, or scale.
• Kitchen cold tap weak, neighbours fine: something on your supply: stopcock, supply pipe, or a leak.

How do I work out what is causing it?

1. Find your stopcock and turn it gently anti-clockwise as far as it will comfortably go, to make sure it is fully open. Do not force it.
2. Unscrew the aerator from the end of the kitchen tap and check it for white grit or scale. Rinse it and refit.
3. Unscrew the shower head, soak it in descaler or white vinegar for an hour, rinse it and refit.
4. Check any small isolating valves on the pipes under the sinks and to the toilets. The slot should run along the pipe when open.
5. Turn every tap and appliance off, read your water meter, wait 30 to 60 minutes without using any water, and read it again.
6. If the meter has moved, turn the stopcock off and watch the meter for ten minutes to see whether the leak is outside or inside.

If the meter keeps moving with the stopcock off, the leak is on your underground supply pipe. If it stops, the leak is indoors.

Why would a leak make pressure drop?

A leak on the supply pipe is water escaping before it reaches your taps. A small leak just costs money. A bigger one, on an old pipe that has cracked or pulled a joint, can lose enough to make a real difference at the tap, especially at the top of a hill where you had little pressure to spare. A sudden drop with no change in the weather and no network work nearby is a classic sign.

Thames Water says that the supply pipe under your garden and driveway is your responsibility, and that once you know about a leak you must fix it within four weeks. If you are on a meter and fix it in time, you may be able to claim a leak allowance.

Is scale really that bad here?

Yes. The Bexley supply zone, which covers Old Bexley and North Cray, is around 284 mg/l on Thames Water’s figures, in its “hard” band. Bexleyheath, just to the north, is around 359 mg/l, which is very hard. Scale narrows everything it touches: aerators, shower heads, thermostatic mixer valves, the small strainers inside combi boilers and electric showers. It is the cheapest cause of low pressure to fix and the one to rule out first.

What about the heating side?

Low pressure on a boiler gauge is a different thing from low pressure at the taps. If your combi boiler’s gauge keeps dropping and there is a warm patch on a floor, that is a heating leak, which is common in post-war houses with copper in screed. Our leak detection in Bexley page covers both kinds. Anything on the boiler itself needs a Gas Safe registered engineer.

When should I call?

• The meter is moving with everything off.
• Pressure dropped suddenly and the neighbours are fine.
• There is a wet patch in the garden or drive.
• You have cleaned the outlets, opened the stopcock and it is still poor.

At the top of a hill, pressure is never going to match the bottom, but it should not get worse over time. If it has, something has changed. For a hill on the other side of the borough, our guide to low water pressure on Sydenham Hill top floors deals with the same physics in a block of flats. More about the area on our Bexley page.

Need a plumber now?

If your pressure has dropped and the meter test points to a leak, Call 07868 281022. Tell us your postcode, what the meter is doing, and whether you can see water anywhere. We cover water leaks in Bexley across DA5, including Joydens Wood, Coldblow and Old Bexley, and we agree the price with you before any work starts.