A hot water accumulator stores heated water for instant use. It's like having a hot water tank — but smaller and more efficient. Here's how they work.
What Is an Accumulator?
An accumulator is a pressure vessel that stores hot water. It maintains pressure in the water system and provides a reserve of hot water.
How It Works
- Water is heated by your heater (gas, diesel, or electric)
- Hot water is stored in the accumulator
- When you open a tap, hot water flows out
- The accumulator maintains pressure
Benefits
- Instant hot water: No waiting for the heater to warm up
- Consistent pressure: No fluctuations when other taps are open
- Energy efficient: Stores heat for later use
- Compact: Fits in small spaces
Types
Expansion Vessels
Small vessels that absorb pressure changes. Not for storing hot water. Costs £20-40.
Hot Water Tanks
Larger vessels that store hot water. Available in 5-20 litre sizes. Costs £50-150.
Accumulators with Heat Exchangers
Combine storage and heating. Water is heated as it passes through. Costs £100-200.
Installation
Location
Mount near your water heater. Accessible for maintenance.
Connections
Connect to cold water inlet and hot water outlet. Use isolation valves for maintenance.
Pressure Setting
Set the accumulator pressure to match your water system (usually 1-2 bar).
Is It Worth It?
For most van lifers, a simple gas or diesel water heater is sufficient. An accumulator adds convenience but also complexity and cost. Consider it if:
- You need instant hot water
- You have multiple water outlets
- You want consistent pressure
Conclusion
Hot water accumulators provide instant hot water and consistent pressure. They're worth it for larger vans or those who need multiple water outlets. For most van lifers, a simple water heater is enough.
