Associations
53
Electrical geyser cylinder
failure guideline
By IOPSA
The Institute of Plumbing South Africa (IOPSA) has facilitated with
industry leaders and geyser manufacturers the development of a
guideline to alleviate confusion in the industry relating to fixed
electrical water heating (geyser) cylinder failures.
The confusion and frustration originated from an
excessive percentage of non-compliant installations
versus actual product failure, and whether poor
installation caused the product failure.
To avoid such confusion, industry has collaboratively
created a document that aims to support plumbing
installers and manufacturers, clarifying critical areas that
determine where incorrect installation can be used as
technical reason to void a warranty claim.
Geyser manufacturers are within their right to void
a warranty claim based on an installation not being
compliant; however, they also have the responsibility
to support their product in the industry if failure is
determined to be a manufacturing fault.
Continued on page 55 >>
No. Description of fault cause Cylinder failure Critical safety
1 Temperature pressure valve (TP valve) rating is higher than water heating cylinder
installed. Yes Yes
3 Installation of reconditioned valves.
NOTE: Some manufacturers do not allow for the installation of a reconditioned valve
onto the cylinders, so warranty will be void. Confirm with the relevant manufacturer
if this point is applicable to the manufacturer. No, if compliant Yes
4 Unbalanced pressure of wat er system. No, may lead to failure
of PCV expansion valve Yes
5 Safety valve is restricted (blocked or damaged). Yes Yes
6 T&P overflow piping is the incorrect size or smaller than the minimum requirement
of 22mm. No Yes
7 Isolating or non-return valve is installed between the hot water cylinder and the
pressure control valve (PCV), expansion relief valve (ERV), or vacuum breaker. Yes Yes
8 No T&P valve is installed. Yes Yes
9 No pressure control valve is installed. Yes Yes
11 Back-siphonage of hot water into the cold water supply — tank warranty intact —
element void.
Note: This may, however, affect copper tanks and tanks that have a PEX lining.
No, may lead to failure
of element Yes
12 Vacuum breakers are installed incorrectly or not above the top of the water heater (the
anti-siphon loop) — tank warranty intact — element void.
Vacuum breaker should be installed 300mm above the cylinder; if it is not possible, it
can be installed within 700mm of hot water supply, directly on the line. No, may lead to failure
of element Yes
13 Discharge pipes that are obstructed and not open to the atmosphere. Yes Yes
Table 1: Installation items that may lead to the failure of a water heating cylinder in an electrical geyser. (Fifteen items
extracted from SANS 10252 and 10254, and discussed as points relating to water heater cylinder failure.)
www.plumbingafrica.co.za
August 2017 Volume 23 I Number 6