Heat Pump Water Quality – Why It Matters and How to Maintain It
by Energie Solutions | Oct 16, 2025 | Air Source Heat Pumps, Heat Pumps, Renewable Energy, Technical Guides
When it comes to heat pump performance and long-term reliability, few things are as critical – yet often overlooked – as water quality. Poor system water quality can lead to corrosion, bacterial growth, and inefficient operation. In this post, we’ll explain what water quality means, why it’s important, and how to maintain it for maximum energy efficiency and system longevity.
What is Water Quality in a Heat Pump System?
Simply put, water quality refers to the condition of the water circulating through your heat pump, radiators, or underfloor heating circuits. This water is continuously heated, pumped, and reheated, completing the cycle countless times. Without proper maintenance, system water can degrade over time. Common issues include:
- Bacterial growth in systems with plastic pipework
- Corrosion and rust from mild steel radiators
- Sludge build-up, which reduces overall efficiency
These contaminants can affect heat transfer and reduce the lifespan of key system components.
Why Maintaining Water Quality is Essential
- It’s a legal requirement (BS7593:2019). The BS7593:2019 standard became mandatory in June 2022, requiring all new and existing heating system installations, servicing, and repairs to follow specific water treatment and protection measures. Compliance ensures your heat pump system operates safely and efficiently.
- It protects your manufacturer’s warranty. With Part L updates to Building Regulations, most heat pump manufacturers now require the use of filters and inhibitors as part of their official installation instructions. Failure to follow these steps can invalidate your warranty, leaving you vulnerable to expensive repair costs.
- It improves efficiency and reduces costs. Contaminated water can cause debris to attach to vital components such as pumps, valves, actuators, and the plate heat exchanger (PHEX). Over time, this build-up leads to reduced flow rates, higher running costs, and premature system failures. Maintaining good water quality helps prevent these issues and ensures optimal system performance.
How to Maintain Heat Pump Water Quality
At Energie Solutions Ltd, our engineers perform a full suite of water quality tests as part of every annual heat pump service.
We begin by checking what solution was used during installation – whether glycol, inhibitors, or the VDI 2035 method. Each option offers effective system protection when properly maintained. If no prior information is available, we conduct a comprehensive multi-step test process:
- Glycol concentration test using a refractometer
- Turbidity test with a turbidity tube to assess water clarity
- Inhibitor test using an Adey Pro Check tool or similar diagnostic device
These results are detailed in a comprehensive service report, giving homeowners full visibility of system health and water condition.
Why Regular Water Quality Checks Matter
Maintaining water quality isn’t just best practice – it’s the foundation of a reliable, efficient, and long-lasting heating system. Benefits include:
- Enhanced energy efficiency
- Extended system lifespan
- Reduced repair and maintenance costs
- Compliance with BS7593:2019 and your manufacturer requirements
Regular annual checks to ensure your heat pump water quality remains within optimal parameters, keeping your home warm, efficient, and worry-free.
Final Thoughts
If you want to get the most out of your heat pump system, prioritising water quality maintenance is essential. It safeguards your investment, reduces running costs, and ensures your heating system runs at peak performance all year round.
At Energie Solutions Ltd, we specialise in professional heat pump servicing, water quality testing, and system protection to keep your installation in top condition.
Choose expertise. Choose reliability. Choose Energie Solutions.
