Direct answer
Instant or continuous-flow systems heat water on demand. They avoid storage losses but must be sized for simultaneous flow and matched to gas or electrical capacity and minimum activation flow.
What can cause the problem or change the decision
| Possible factor | What to record safely |
|---|---|
| Peak simultaneous outlets | Estimate simultaneous shower and tap use |
| Gas pipe or electrical capacity | Confirm energy connection capacity |
| Distance to fixtures | Compare rated flow at required temperature rise |
| Minimum flow and temperature rise | Plan for service access |
Safe checks before professional work
- Estimate simultaneous shower and tap use
- Confirm energy connection capacity
- Compare rated flow at required temperature rise
- Plan for service access
Stop and get help
Gas, combustion and high-current electrical work must be completed by authorised trades.
What information helps the next step
Timing
Note whether the symptom is constant, linked to rain, linked to a fixture or only at peak use.
Extent
List each affected outlet, room or inspection point without opening regulated components.
History
Keep previous invoices, camera footage, product model and renovation details.
Safety
State any gas smell, hot discharge, sewage, electrical proximity or structural movement immediately.
Compare hot-water system types
| Type | Useful when | Check before choosing |
|---|---|---|
| Electric | Existing electrical setup and simple storage replacement | Tariff, capacity, recovery and electrical scope |
| Gas | Suitable gas supply and strong recovery needs | Gasfitting, flue, ventilation and rated flow |
| Solar | Suitable roof and long-term solar contribution | Roof access, booster, shading and current incentives |
| Heat pump | Efficient electric replacement with suitable outdoor space | Climate performance, noise, airflow and recovery |
| Instant | On-demand use with adequate energy capacity | Simultaneous flow, pipe/electrical capacity and distance |
Frequently asked questions
Is this a complete DIY repair procedure?
No. It provides safe consumer observations and stops before regulated, hazardous or specialist work.
Which professional service matches this issue?
Start with Hot Water Plumber: What the Service Covers. The actual diagnosis may identify a different work category.
How can I plan the cost?
Use Hot Water Installation Cost for sourced planning context, then compare written local quotes.