HX Pool and Spa Heater
Page 5
CORROSION PREVENTION IN HEATERS
All pool and spa heaters use copper or copper nickel to make their heat exchangers as it is the
most efficient material in transferring heat from the combustion chamber into the water. The
typical life expectancy of a well maintained pool/spa heater is between 8 and 15 years.
Often the same heat exchanger used in residential and commercial boilers and hot water systems
will have a life expectancy of 20 years.
The addition of sanitisers (Chlorine, Bromine etc) and other water balancing and conditioning
chemicals can increase the rate of wear and tear on the heat exchanger and associated parts in your
heater.
There are three most common reasons for heat exchanger corrosion which can be avoided with a
little care and attention.
1.
Excessive Sanitiser.
This means too much Chlorine or Bromine in the water. Be careful, if
the level of Chlorine or Bromine is excessively high your test kit (and the pool shops) may not
read accurately or indeed may show a nil reading. Any time a salt chlorinator is operating for
extended periods, (when heating the swimming pool from cold), particularly if the weather is
overcast or the pool enclosed or covered, the Chlorine level may exceed normal levels. When
heating a Spa Pool, turn the chlorinator down or off for the duration of the heating period.
2.
Out of balance water
. The water balance is a combination of pH, total alkalinity, Calcium
hardness and temperature. These measurements must be at the correct levels to maintain balanced
water and effective sanitation of your pool. Balanced water will help prevent corrosion of your
heater. Balanced water should be between 7.2 - 7.8 pH.
3.
The addition of acid to lower pH
. Acid must always be added in small quantities and spread
over the pool surface evenly, not added in to the skimmer. Do not add a litre at a time, add a
cupful each day to lower your pH.
4.
Never add chemicals to skimmer
- dilute and circulate as far away as possible from skimmer.
If you have a
salt chlorinated
INDOOR pool or COVERED pool be very careful of the level of
Chlorine being produced. If you use a salt chlorinated spa be very careful of the level of Chlorine
as the Chlorinator is usually sized for the pool and therefore should be switched off when heating
the spa. Leaving the chlorinator on can raise the chlorine level very rapidly in a small volume of
water.
These comments are intended as a guide only and are not definitive answers or recommendations
on pool water chemistry. Hurlcon’s intention is to provide a little understanding of the potential
problems of water chemistry and the dangers of corrosion to heaters (and other pool equipment
and fittings).
You should always seek the advice of your local pool shop professional and provide him with as
much information and feedback as possible when analysing your pool and spa water and
obviously be sure to tell him you have a heater connected to the system even though it may not be
in constant use.
YOUR WATER SHOULD BE ADJUSTED & BALANCED PRIOR TO ANY CORRODED
PARTS BEING REPLACED.
