What about control valves?
By Patrick Gordon- consultant
When replacing an HWC, must I replace all the control valves?
TECHNICAL 35
This answer is not a straightforward yes / no scenario. When replacing the Hot Water Cylinder( HWC), we need to first ascertain why the HWC failed in the first place. It could well be that the HWC failed due to a malfunctioning control valve.
To start off we need to understand what the function is of each component in the system. We have dealt with that in some of the previous articles but feel free to contact your manufacturer, or the writer, for more detailed information.
writing of any non-compliances before issuing them with a quotation. Make sure that you give a detailed quotation of what you are tendering to repair. Get their acceptance of the quotation in writing. These points are to protect you from any disagreements that may arise when it comes to payment afterwards. PA
For any further information on this topic please contact the writer: PA Gordon on patrickg @ splashworks. co. za.
Secondly, we need to make sure that the control valves are performing according to the desired manufactured specifications. This would mean that you would need to know what the performance criteria are( SANS198), and that you have the appropriate equipment to perform the necessary tests.
If you have any doubt about the integrity of a control valve it would be prudent to service it, and restore it back to manufacturers specification, or to replace it.
" To start off we need to understand what the function is of each component in the system "
If all the control valves are found to be in good order they can be re-used. The important part is to make sure that your installation complies to the latest version of SANS 10254. I include an extract: 4.3 Operation of the system 4.3.1 General 4.3.1.1 New installations All the components of the system shall be installed in such a manner and position as to ensure a) the safe and effective operation( both mechanical and electrical) of the system and of each individual component part, b) the easy, effective and correct removal and replacement of component parts or spare parts during maintenance, replacement or repair, and c) the effective discharge and drainage of water from the system.
Photos supplied by Advanced Valves
NOTE: Particular attention is drawn to the future replacement of anodes, heating elements, thermostats and safety valves on closed type water heaters, and due allowance should be made to ensure such correct replacement.
You also need to know what the manufacturer of the HWC requires during a replacement. Some manufacturers and insurance companies require that you replace the HWC and all the ancillaries. You also need to keep in mind that all installations need to comply to SANS 10254.
If you get to an installation that does not comply it is your responsibility, as an industry specialist, to notify the customer in
June 2025 Volume 31 I Number 04 www. plumbingafrica. co. za