Hayward HeatPro HP50TA Troubleshooting Manual page 32

Alternative Leak Detection Methods
As our industry has evolved the issues we see with heat pumps today have become more diverse and complex.
It requires more than a set of gauges and a VOM to diagnose many of these problems.
One of the areas where new techniques and tools are required is in finding refrigerant leaks, particularly on
R-410A systems. Due to the high operating pressures of this refrigerant it is possible to have a refrigerant leak
that eludes a hand held Halon type leak detector. The leak rate may be significantly less when the heat pump is
off (the only time you can properly "sniff" the unit) than it would be when the heat pump is operating.
A second proven method of finding leaks it to pressurize the system with nitrogen and use a liquid leak detector
such as Big Blue to detect leaks. The maximum pressure you can use in this method is on the data plate of all
heat pumps. This is the pressure Hayward pressurizes the system to during manufacture. The majority of leaks
can be found using one or both of these methods.
Unfortunately, at times a leak may still remain elusive, even at the hands of the best technician.
A third proven method is to inject a fluorescent dye into the system and use an ultraviolet light to detect the leak.
We would recommend this method after attempting to discover the leak using the two methods outlined above.
Given the sophistication of today's systems as well as the compact designs we believe that having a dye system
leak detector is a requirement in your tool box. If you do not have a dye injector/ UV light detector kit you will need
to purchase one. You should be able to purchase a Spectronics kit that contains the UV light, UV protective
glasses, cleaner, and enough dye for at least 2 systems for around 100.00 U.S.