Group B Friday practical

All to work with Ian initially to discover the procedures of the servicing and commissioning of the unvented hot water and open vented hot water. All who completed the commissioning last Friday to move onto the open vented checks.

All who were not in attendance last Friday with Ian to be trained on servicing, commissioning and checks on an unvented hot water cylinder.

1. Have the manufacturers’ instructions for your cylinder available. If these are not to hand the manufacturer’s website should be consulted where downloadable copies can be accessed.

2. Discuss with you whether you know of any existing issues with the system and/or whether it has been performing satisfactorily recently, eg. Has the water been hot enough, have you noticed any leaks, has there been any drips or flow of water noticeable at the tundish, is the flow sufficient?

3. Visually check the cylinder for any obvious defects. Make suitable checks to assess whether or not the appliance has been installed in accordance with the manufacturer’s instructions and any relevant Regulations.

4. Identify the type of expansion system used – this will be either an internal expansion volume or an external expansion vessel. Check that the expansion system is installed according to manufacturer’s instructions. Generic advice is given below. In all cases, where manufacturer’s instructions conflict with the recommendations below, manufacturer’s instructions should take precedence.

a. For a separate expansion system, close the mains supply, open a hot tap at the same level or above the cylinder to depressurise the cylinder. Check the pressure of the expansion vessel. Recharge to the labelled pressure on the vessel. Close hot tap and open mains supply.

b. For a bubble top/air gap system. Partially drain the cylinder according to the manufacturer’s instructions and refill.

c. For alternative systems, follow the manufacturer’s instructions.

5. Clean the line strainer. Check the condition of any seals and replace if necessary.

6. Check the T&PR and Expansion Valves are operating correctly. Water should be run through each valve for approximately 30 seconds to ensure that any loose scale build up, or debris is flushed through before re sealing.

7. Whilst checking the safety valve operation above, check that the tundish drains and discharges correctly, and there are no blockages.

8. Check that any interlocks with external controls (such as your heating programmer) are operating correctly. Note: it may be necessary to over-ride the programmed time settings to do this, the engineer should return the system to its original settings on completion of these checks.

9. With the unit hot, check the outlet temperature at the outlet closest to the cylinder to determine correct functioning of the thermostat. Note: thermostatic controls will have an operational tolerance and switching differential so the temperature recorded may vary from the “set” temperature by a few degrees. Most storage cylinders recommend storing hot water at a temperature of approximately 60oC. When checking the outlet temperature ensure the outlet used is not fed via a thermostatic blending valve, such as a mixer shower or some baths, which wil reduce the hot water temperature at the outlet to below the storage temperature.

10. Carry out a visual check of any electrical wiring associated with the cylinder, immersion heater and its controls. For further details of the electrical checks that should be performed refer to HWA Guidance document https://hotwater.org.uk/uploads/5A37CB70B704A.pdf. 

11. If the system has an anode this will be checked in accordance with the servicing requirements in the manufacturer’s instructions.

12. Check the condition of the electrical housing(s). If broken, or cannot be securely closed then a replacement is recommended.

13. Check condition of flexible hoses where used.

14. Complete the Benchmark service record, or equivalent Commissioning Certificate Service Record, and provide any additional work documentation either routinely or if you request this.

Based on common industry guidance, a variety of checks and maintenance tasks should be carried out on an open vented hot water system to ensure its longevity, safety, and optimal performance.

Here are the key checks and maintenance activities: Routine Maintenance and Inspection

• Visual Check for Defects: The cylinder should be visually checked for any obvious defects, including signs of corrosion or leaks.

• Check for Leaks and Dampness: Conduct regular checks for leaks or any other visible wear. Inspect the surrounding area for dampness, which may indicate a potential issue.

• Anode Rod Inspection: Regularly inspect the anode rod, which protects the cylinder from rust by attracting harmful particles.

  • If the rod shows signs of significant deterioration or is less than half its original size, it should be replaced to extend the cylinder's life.

• Ventilation Check: Ensure there is adequate airflow around the cylinder to dissipate excess heat, which is especially important if an immersion heater is used. Good ventilation also helps to minimize the risk of corrosion.

• Insulation Check: Inspect the cylinder and connected pipework insulation for any signs of wear, damage, or gaps to minimize heat loss and ensure energy efficiency.

Annual Maintenance (Recommended by a Qualified Professional)

• Sediment Flushing: Over time, sediment (dissolved minerals) can build up at the bottom of the cylinder, reducing efficiency and affecting water quality.

  • It is advised to have the hot water cylinder drained and flushed yearly to prevent excess build-up.

• Temperature and Pressure Relief (TPR) Valve Test: Regularly test the TPR valve to ensure it functions correctly.(if fitted).

  • This is typically done by briefly lifting the lever to allow a small amount of water to discharge, verifying the valve opens and closes smoothly. If the valve doesn't operate properly, consult a professional.

• Vent Pipe Maintenance: The vent pipe requires regular maintenance to ensure proper functioning. Check for any accumulation of debris or blockages that could affect the performance of the system.

Commissioning Checklist Items

During installation or major maintenance, a commissioning checklist should verify key components are correctly fitted and compliant:

• The vent pipe has been installed to the appropriate standards (e.g., BS6700/BS5449).

• For indirect systems (heated by a boiler), a cylinder thermostat has been fitted in the recommended position.

• The hot water is controlled by a programmer or time switch.

• All appropriate pipes, including the vent pipe, have been insulated up to 1 metre or to the point where they become concealed.

• If an immersion heater is fitted, it should have a non-auto resetting energy cut out.

For complex tasks like sediment flushing or any work involving safety components, it is strongly advised to seek the help of a plumbing and heating professional.

Has everyone completed this training with Steve Bell last Friday?

• Tobey Williams Eccles - Page 48  - training on the installation of a shower

• Harley Shepherdson - Page 48 - training on the installation of a shower

• Keigan Hill - Complete the reflective task on the unvented cylinder - then training on sanitation section page 13 onwards

• Hassan Ibrahim - Page 13 and 14 to complete before anything else

• Kian Pendlebury - Cold water disinfection

• Jorge Williamson - Complete page 18 sanitation testing

• Harley Scoular - Complete page 18 sanitation testing

• Levi Davis - Cold water disinfection

• Davi Ortiz - Hot water service 

• Lewis Calligan - Page 23 and 24 - Macerator install and fault finding training

• Caden Symmonds - Page 23 and 24 - Macerator install and fault finding training

• Yahya Sakeria - Page 31 and 32 to be completed backflow prevention

• Mo Atcha - Page 23 and 24 - Macerator install and fault finding training

• Ben McGarry Bolton - Page 19 and 20 training on sanitation fault finding