Solar & Gas Geyser Safety Pretoria Gauteng
The intention of this article is to inform you, in the interests of your and your family's safety, what
you should and should not see if you happen to stick your head into the ceiling space to check out your geyser. If your geyser installation
is significantly different from what is described here, I suggest that you get a reputable plumber to repair it.
In this article
I will describe the typical basic requirements of a sound, modern high pressure, horizontal installation. The following description
relates to a modern high pressure (400/600Kpa) system typically made by Kwikot South Africa.
Horizontally mounted 150 or 200 litre
units are by far the most common in modern domestic installations. Less common are old low pressure systems (100kpa) open pipe or
"Latco" type systems. Be aware that the parts are NOT interchangeable between the two distinct systems - High pressure and Low pressure!
It is possible to remove an old low pressure system and replace it with a modern high pressure system however - you buy a new high
pressure geyser and install it according to the current specification. Vertical geysers are also common. The same rules apply but
there are some special considerations detailed at the end - with a diagram.
Safety tips for geyser installation
is what you should see - in no particular order:
Drip Tray - The most obvious thing that you should notice right away. The geyser sits
in a tray made of plastic (often red) or tin plate. I prefer the plastic ones. They don't leak. Since June 2001, the drip tray is
not optional - its got to be there and there has to be a drain pipe for it! The drain is a 50mm PVC waste pipe that drains the tray
by piping the water out the house. I have seen many drip trays installed without drains! If your installation pre-dates June 2001
you may want to get a plumber to look at it. There is a fair chance that there is no drip tray.
Vacuum Breakers - The next
most noticeable feature would be the vacuum breakers. These are small brass components mounted at the end of a 30cm length of pipe.
The two vacuum breakers stand vertically about 30cm above the geyser. These are important, as they stop water siphoning out the geyser
when the cold supply is stopped. The other other function is to prevent a vacuum forming in the tank and collapsing it. It can be
argued that this is the primary function, but I don't see it as such. Remember that vacuum breakers are a reasonably new requirement
- there are still thousands of old HP systems out there without vacuum breakers and I am yet to see one collapse. Just because I haven't
seen it doesn't mean it's not happening however! It is also more likely to happen in a multi-story building because the siphon can
draw a more powerful vacuum. New systems must have breakers!
Shut Off Valve - A shut off valve (tap) on the cold water side. The cold
water side is the side that directly connects to the drain cock and enters the geyser at the bottom. After the shut off valve you
would normally find a Pressure Control Valve (PCV). There are a number of different types, mostly made of brass but some are made
of plastic. You should notice a overflow pipe connected to the PCV that leads to the outside of the building. This is where the PCV
releases pressure and this is the pipe that often drips. Don't panic if you cannot find the PCV next to the geyser - it may be mounted
up to 10 metres away, often in a more accessible place on a wall outside. Sometimes it's in a little plastic box outside.
Safety Valve -
A safety valve, known as the Temperature and Pressure safety valve (T&P Valve) mounted on the geyser towards the top, often on
the opposite side to the drain cock. This is a vital component that should never be messed with or 'repaired'. This valve should have
a metal (copper or steel) pipe connected to it and the pipe must lead directly out the building. This vent pipe is an important safety
feature of the whole system. It must be made of copper or steel - not plastic. The pressure rating on this valve must match the pressure
rating on the geyser. The T&P valve is the least optional component - it has to be there!
Support - The weight of the geyser must
be adequately supported on the roof trusses - a minimum of two supports under the 'feet' of the geyser. If it looks shaky get a plumber
to check it out. Nothing like a full (hot) geyser on the kitchen table to get everyone talking!
Electrical Isolator - electrical isolator
switch within about 1m of the geyser. This was not a requirement on old geysers, but it is now and it's worth fitting one. The geyser
has to be earthed! I have seen many geysers with the earth wire unconnected. All the copper pipes must also be earthed and bonded
to the geyser earth. This is not a trivial precaution! Get a qualified electrician to check your installation if the bonding is missing
or looks dodgy. Electrocution in the shower is always unpleasant!
Element Cover - There should be a cover over the thermostat and
element. Again, these are often just left lying next to the geyser. There are essentially only two primary thermostat types - the
modern round "Kwiktherm" in newer Kwikot geysers and the VK (rectangular block) type in older geysers and in some newer non-Kwikot
The geyser may be fed (cold water) with polcop (plastic) pipe - up to the shut off valve, but the pipe into and out of the
geyser must be copper or galvanized steel. The PCV and T&P vent pipes also have to be steel or copper, especially the T&P
vent. The hot water side should be copper, steel or suitably rated (70°) plastic or composite pipe. Note that you must have at least
1m of copper/steel pipe out the geyser - you may not connect plastic (composite) pipe directly to the geyser.
As above, the PCV and
T&P must be made of copper or steel - particularly the vent out of the T&P valve. Why you ask? Well, in the event of the T&P
(safety) valve releasing, the water coming out is likely to be very, very hot! If the pipe is made of polycop then it will simply
melt and then vent this water randomly into your ceiling space! This is not likely to happen on the PCV valve, but the regulations
say that it should also be made of metal. I have seen a number of installations where the installer has simply run a short length
of 22mm copper into the drip tray with the idea being that the T&P can vent directly into the drip tray. A very bad idea because
the hot (100° +) water/steam melts the drip tray and the PVC drain pipe.
Note that water enters (cold) and leaves (hot) from above
the geyser top - look at the diagram below. The PCV is typically above the geyser and the cold water flows down into the geyser. This
is quite important because it forms an anti-syphon loop that prevents the geyser from draining back through the inlet in the event
of a water supply failure. If you get hot water coming out your cold taps when the water supply fails then this is not working correctly.
Get a plumber to come and have a look at it.
The pipes into and out of the geyser should be lagged. This is important if you have
'Think Pink' or 'Isotherm' ceiling insulation. This is for two reasons: You lose heat through the unclad hot water pipes and all the
pipes are more prone to freezing (and bursting).
There must obviously be no signs of water! Any water lying in the trip tray is a
sign of trouble.
I have described a typical, modern high pressure (400-600kpa) system - by far the most common type in South Africa.
are different although much of the description still applies.
Low pressure systems (100kpa) are significantly different, but fairly
The same general rules apply as above, but the outlet and T&P valves must be at the very top of the geyser. If the
geyser does not have two outlets at the top then a banjo joint should be used to combine the two. The element and thermostat must
always be at the very bottom. Allow enough room underneath to allow the changing of the thermostat and element. I suspect that there
is a greater temperature differential in a vertical geyser - in other words the thermostat is a couple of degrees cooler than the
outlet water. I tend to turn the thermostat down a tad more for this reason.
from an article by Blockbuster Plumbing in Home-Dzine
both my Comprehensive and Critical Home Inspection the inspection of your geyser is one of the most important items that
is covered to ensure the safety of you and your family.
An incorrectly installed hot water heaters is the most common defect
discovered by me in South African homes during a home inspection. These defects can be very dangerous and clearly result
when untrained, or un-supervised workers are left alone in the roof cavity to do the geyser installation. The videos below show extreme
cases of a geyser explosion. Don't let this happen in your home.