Sudden low pressure usually means a blockage, leak, or valve issue. It’s one of the most common home problems.
Common causes
- Partially closed valves
- Blocked aerators
- Leaking pipes
- Boiler pressure issues
- Mains supply problems
1. Valves not fully open
A bumped valve can restrict flow.
Quick fixes:
- Check stop tap is fully open
- Check isolation valves under sinks
2. Blocked tap aerators
Limescale builds up fast.
Quick fixes:
- Unscrew the aerator
- Soak in vinegar
- Rinse and reattach
3. Boiler pressure
Low boiler pressure affects hot water.
Quick fixes:
- Check gauge
- Top up to 1–1.5 bar
4. Leaks
Even small leaks reduce pressure.
Quick fixes:
- Check under sinks
- Look for damp patches
- Listen for dripping
What to try first
Clean tap aerators — it’s the fastest fix.
When to call a professional
If pressure drops across the whole house suddenly.