How to Take a Water Sample from a Hot Water Cylinder (Calorifier)
Important: Read Before You Begin
Hot water cylinder samples must be taken carefully to ensure both safety and accuracy. Please follow this guide closely.
Pre-Requisites – What You’ll Need
✅ The sample bottle provided by DS Water (contains Sodium Thiosulphate – do not rinse).
✅ Clean hands – wash with soap and water before handling the bottle.
✅ The online form emailed to you by DS Water, which must be completed after sampling.
✅ A pen to label the bottle with date, time, and location details.
✅ The return packaging, specially designed to fit into almost all Royal Mail post-boxes, for easy posting back to the lab.
✅ A temperature probe (if available) to measure the water temperature at the time of sampling.
Step-by-Step Guide to Sampling
- Preparing for Sampling
- Wash your hands thoroughly with soap and water before handling the bottle.
- Ensure your sample bottle is in date and do not open it until ready.
- Identify the cylinder drain valve or designated sampling point.
- If using a drain valve, flush at least 5 litres of water before taking the sample.
- Taking the Water Sample
- Carefully open the drain valve or sampling point and allow water to flow for at least 10 seconds.
- Slowly fill the bottle from the water flow, ensuring the bottle does not touch the valve.
- Fill the bottle to the neck only – do not overfill.
- Securely replace the cap and gently invert the bottle several times to mix the neutraliser with the sample.
- If available, record the water temperature immediately after sampling.
- Completing the Online Form & Returning the Sample
- Fill in the online form with:
- Sample location description
- Time of sampling
- Water temperature at sampling
- Place the bottle in the packaging and post it via Royal Mail as soon as possible.
- Fill in the online form with:
- Receiving Your Results
- Results can take up to two weeks.
- Once received, they will be processed within an hour, and you will receive an interpretation report.
If you have any questions, please email info@dswater.co.uk.
