Stop using the shower or bath if water is reaching ceilings, walls or electrical fittings
Isolate local water supplies where possible. Electric showers must be isolated electrically before any internal work, and temperature faults that create scalding risk should be treated as urgent.
MOST LIKELY CAUSES
Start with these
Symptom variations Match the exact pressure, temperature or leak pattern. ⌄
- Other hot taps are normal
- All hot outlets are cold
- Shower works only at one temperature
- Electric shower power light is on but water stays cold
- Problem started after plumbing work
Quick checks Simple checks before dismantling shower or bath components. ⌄
- Identify whether the problem affects pressure, temperature, drainage or leakage.
- Check nearby hot and cold outlets for similar symptoms.
- Clean accessible shower heads, filters and waste covers.
- Inspect hoses, seals, trays and accessible joints.
- Stop testing immediately if water appears below or near electrics.
Step 1 — Check hot water elsewhere Use controlled tests and stop if water reaches ceilings or electrics. ⌄
Process
Run a nearby hot tap.
Step 2 — Check local hot-side valves Use controlled tests and stop if water reaches ceilings or electrics. ⌄
Process
Confirm accessible service valves are open without forcing them.
Step 3 — Identify shower type Use controlled tests and stop if water reaches ceilings or electrics. ⌄
Process
Determine whether it is mixer, power or electric.
Common causes explained Why shower and bath faults develop. ⌄
A cold-only shower may have no hot-water supply, a stuck mixer cartridge, closed hot valve, blocked hot inlet, boiler issue or failed heating section in an electric shower.
Shower and bath faults often depend on when water is flowing, draining or hitting a sealed surface. Controlled separate tests help distinguish supply, mixer, waste and enclosure faults.
Advanced diagnostics Plumber or appliance-engineer checks. ⌄
- Test hot inlet flow and temperature.
- Clean filters and check valves.
- Replace mixer or thermostatic cartridge.
- Diagnose boiler or cylinder supply issues.
- Test electric-shower heating components safely.
Parts that may need replacing Common components linked to this fault. ⌄
- Mixer cartridge
- Thermostatic cartridge
- Inlet filter
- Service valve
- Electric-shower heating component
When to call a plumber or engineer Conditions that should end basic troubleshooting. ⌄
- Water is leaking through a ceiling or near electrical equipment.
- The shower temperature is dangerously hot or unstable.
- An electric shower has an internal heating or power fault.
- The tray, bath or concealed pipework must be removed for access.
- A thermostatic cartridge cannot be calibrated safely.
- The fault returns after basic cleaning or seal replacement.
Frequently asked questions Common questions about shower and bath faults. ⌄
Why does a shower drip after it is turned off?
Large heads and hoses can hold water temporarily. Continuous fresh dripping points to a leaking control valve or cartridge.
Can failed sealant cause a ceiling leak?
Yes, but waste joints, pipe connections and tray movement must also be ruled out.
Why does shower temperature change when another tap is used?
The hot and cold pressures may be unbalanced or the thermostatic cartridge may not compensate correctly.