Plumbing Maintenance Guide

1. Measure, do not estimate

Fit a gauge at the nearest point to the supply

Static pressure is read with everything closed. Running pressure is read with one tap fully open. A large gap between the two points at a restriction rather than a supply problem.

2. Measure the actual flow

Time a bucket fill at a fully open tap

A 20 litre bucket filling in 60 seconds is 20 l/min. Compare against what the fixture needs. Pressure and flow are different problems and are fixed differently.

3. Establish whether it is the whole property or one outlet

Test at several fixtures

One bad outlet is an aerator, a service valve or a flexible hose. Every outlet poor points upstream to the main, the storage, the pump or the meter.

4. Check the simple restrictions first

Aerators, isolating valves, flexible connectors

Unscrew and clean aerators. Confirm every isolating valve is fully open, including the one at the meter. Collapsed flexible hoses restrict flow with no visible fault.

5. Check storage and the float valve

Where supply is intermittent and tanks are used

A tank that is not filling gives falling pressure through the day. Check the float valve, the inlet strainer and whether the tank is high enough — head is roughly 0.1 bar per metre of height.

Caution: A tank that overflows continuously is a failed float valve and wastes billed water

6. Check the booster set

Pump, pressure switch and vessel

A waterlogged pressure vessel makes the pump cycle rapidly and the pressure surge and drop. Check the air charge with the system drained. Confirm cut-in and cut-out against the switch settings.

Caution: Rapid cycling destroys pump motors and pressure switches quickly

7. Look for a hidden leak

If nothing upstream explains the loss

Close every outlet, note the meter, wait an hour. Movement with everything closed is a leak. See the concealed leak procedure.

1. Confirm a leak exists

Meter test with everything closed

Close all outlets and appliances. Record the meter. Leave one hour. Any movement is loss. Photograph both readings — a recorded figure settles an argument with a landlord or an insurer.

2. Split the system

Isolate section by section

Close the isolating valve to one branch at a time and repeat the meter test. The branch where movement stops contains the leak. This is the step that saves the wall.

3. Separate supply from drainage

They present the same way and are fixed differently

A supply leak shows on the meter. A drainage leak does not — it only appears when something is discharged. Run one fixture at a time and watch.

4. Read the evidence

Damp patterns, staining, sound

Damp rising in a wall is usually below the leak, not at it. Warm patches on a floor point at a hot line. A hiss with everything closed is pressurised loss.

5. Open the smallest possible access

Only once the branch is known

Expose at the most likely joint first — changes of direction, fittings and penetrations fail far more often than a straight run of pipe.

Caution: Never cut blind into a slab; buried services may run alongside

6. Repair to the material, not with whatever is to hand

Matched fittings and correct jointing

PPR is fusion welded, PVC is solvent cemented, PEX is crimped or push-fit, galvanised steel is threaded. Mixing methods or metals creates the next leak.

Caution: Copper joined directly to galvanised steel corrodes galvanically; use a dielectric fitting

7. Pressure test before closing up

Prove the repair while it is still visible

Re-pressurise and hold. Repeat the one-hour meter test. Only then make good the wall or floor.

1. Identify when it happens

On closing, on opening, or continuously

A bang when a tap or solenoid closes is classic hammer. Noise while water runs is velocity or a loose pipe. Noise on opening is usually air.

2. Check the pressure

High static pressure makes hammer worse

Where mains pressure is high, a pressure reducing valve set to a sensible working figure removes the energy behind the shock.

3. Find the fast-closing valve

Washing machines, dishwashers, solenoids

Appliance solenoids close in milliseconds, which is what generates the shock. The arrestor belongs close to that valve, not at the far end of the run.

4. Check pipe support

Unclipped pipe amplifies everything

Clip pipework at sensible intervals and wherever it changes direction. A pipe drumming against a joist sounds like a plumbing fault and is a carpentry one.

5. Fit or recharge an arrestor

Air chambers waterlog and stop working

A traditional air chamber fills with water over time and must be drained to restore the cushion. A diaphragm arrestor does not, which is why it is preferred.

1. Establish how much of the system is affected

One fixture or all of them

A single slow fixture is a trap or branch. Several at once, or the lowest fixture backing up first, means the main run or the soil stack.

2. Check the vent before rodding

Slow drainage with gurgling is often a vent fault

A blocked stack vent makes traps siphon and drainage gurgle. Clearing the blockage will not fix it and the symptom returns.

3. Start at the nearest access

Trap, rodding eye or chamber

Open the trap over a bucket first. Most kitchen blockages are within reach of a hand and a bucket, with no rods and no chemicals.

4. Rod towards the blockage, not through it

Turn rods clockwise only

Reversing direction unscrews the rods and leaves a section in the drain, which turns a blockage into an excavation.

Caution: Never force rods into a pipe you cannot identify

5. Flush and confirm

Full-bore flow, not a trickle

Run a full basin or bath of water. A blockage that has been bored through rather than cleared will pass a trickle and fail on volume.

6. Deal with the cause

Grease, roots, bedding failure or falls

Repeat blockages at the same point are structural: a collapsed section, a root ingress or insufficient fall. Rodding it monthly is not a repair.

1. Observe the cycling pattern

The pattern names the fault

Rapid on-off cycling is almost always a waterlogged vessel. Running continuously without reaching cut-out is a leak, a worn impeller or a suction problem. Not starting at all is electrical or the switch.

2. Check the vessel pre-charge

System drained, then read the schrader valve

Pre-charge is set slightly below pump cut-in. Water coming out of the schrader valve means the diaphragm has failed and the vessel must be replaced, not recharged.

Caution: Never check pre-charge with the system pressurised

3. Verify the pressure switch settings

Cut-in and cut-out against the gauge

Compare what the switch is set to against what the gauge actually does. A switch with burnt or pitted contacts reads correctly and acts late.

4. Check the suction side

Most pump faults are upstream of the pump

Check the foot valve, the strainer and for air ingress on the suction line. A pump cannot pull what it is not being given, and cavitation sounds like gravel in the casing.

Caution: Cavitation destroys an impeller quickly; stop the pump and find the cause

5. Measure the motor electrically

Running current against nameplate

Current well above nameplate means a mechanical drag or a failing winding. Current well below, with the pump running, usually means it is not moving water.

6. Check dry-run protection

Confirm it works before relying on it

Where supply is intermittent, dry-run protection is the difference between an empty tank and a replacement pump. Test it rather than assuming it.

1. Watch a fill cycle

The failure shows itself

Overflow running means the valve is not shutting. A tank that never fills means it is not opening, the inlet is restricted, or supply is arriving only briefly.

2. Service or replace the float valve

Washer, seat and arm

Most valves fail at the washer or seat. A float that has taken on water sits low and holds the valve open — it will feel heavy in the hand.

3. Set the level properly

Below the overflow, not at it

Set shut-off with usable clearance beneath the overflow so a small overshoot does not discharge. An overflow that runs is billed water leaving the property.

4. Check the overflow itself

It is the last defence

The overflow must be at least as large as the inlet and must discharge visibly. An overflow piped somewhere nobody looks hides the very fault it exists to reveal.

5. Inspect and clean the tank

Sediment, light and cover

Sediment reaches the outlet as the level drops. A tank passing light grows algae. The cover and insect screen are part of the water quality, not an accessory.

1. Separate no hot water from not enough

Different faults entirely

None at all is supply, element or thermostat. Some, then cold, is capacity, a failed lower element on a twin-element cylinder, or crossed flow mixing hot with cold.

2. Confirm power is arriving

At the appliance, not at the board

Check the isolator, the breaker and any thermal cut-out. Many cylinders have a manual reset cut-out that trips and is never looked at.

3. Test the element and thermostat

Resistance and continuity, power off

An open-circuit element reads infinite resistance. An element shorting to the body will trip an RCD every time and is a shock hazard.

Caution: An element that trips the RCD must be replaced, never re-energised

4. Check the relief valve

Discharging or seized

A relief valve that weeps continuously is either failed or telling you the pressure is too high. A seized one is far more dangerous than a dripping one.

Caution: If the relief valve discharges regularly, find out why before replacing it

5. Look for scale and sediment

Where water is hard

Scale insulates the element, so it runs hotter and fails earlier, and sediment reduces usable volume. Draining periodically extends element life.

6. Verify the delivered temperature

Measure at the outlet

Stored temperature and delivered temperature differ. Where a blending valve is fitted, check it before condemning the cylinder.