Pressurisation Unit Fault

What is a pressurisation unit?

We get a few calls from people who have a BMS controls panel. The pressurisation unit indicator being one of them. Firstly lets address what a pressurisation unit does.

A pressurisation unit is a mechanical device used to maintain and regulate pressure within a system, typically in heating, hot water, or chilled water systems. Here’s how it works:

1. System Pressure Maintenance: A pressurisation unit ensures that the system maintains the correct pressure. It compensates for any water loss due to leakage, preventing the system from becoming under-pressurized.
2. Sealed Systems: It is commonly used in sealed heating and chilled water systems. These systems are closed-loop, meaning they don’t allow water to escape or enter freely. The pressurisation unit helps maintain the desired pressure within this closed system.
3. Replacing Lost Water: If there’s a leak or water loss, the pressurisation unit automatically adds water back into the system. This prevents issues like reduced flow, inefficient heat transfer, or airlocks.
4. Peripheral Pumps: The unit uses small peripheral pumps distributed throughout the system. These pumps help maintain pressure by circulating water as needed.

In summary, a pressurisation unit ensures that your system operates at the right pressure, improving efficiency and preventing problems caused by low pressure.

the system pressure at which the low pressure alarm relay will operate, typically

So what are the tolerances?

Typically for a mikrofill type unit see the thresholds below.

Alarm Low Pressure – set 0.6 – 0.7 bar below the cold fill pressure.

Alarm High pressure – the system pressure at which the high pressure alarm relay will operate, typically set 0.2 – 0.3 bar below the system safety valve setting.

The information above is a typical reading. Your thresholds may vary so please consult your operations manual for your unit type.

Can you help?

If the issue is a confirmed electrical one and for some reason our installation has failed under warranty then yes. We can have an engineer attend.

If the problem is a mechanical one as in you have a leak causing pressure loss then it falls under you mechanical contractor.