When testing a pool heater after installation, you want to use it the same way a homeowner or guest would use it. If your controls haven’t been set up, nothing will happen, so you need to make sure you turn on the heater the same way that the homeowners or guests do it to make sure it works. Configure the controls in a way that will fit the customer’s usage. To do that, read the manual and look for the section about the external control. You’ll get a description of the two types of controls: two-wire and three-wire.

We use the two-wire configuration on more advanced external control systems; it has its own thermostat, and the customer sets the temperatures from the external control. The manual should explain the process of setting up the controls in detail.

The three-wire configuration has the heater send a signal and allows that to determine if the heater is in pool mode or spa mode. If the heater receives the signal back, it’s in spa mode; if the other terminal receives the signal, then the heater is in pool mode. Programming is required, and you must test these modes.

When servicing a pool heater, think about what a customer interacts with. Make those areas your priority so that the customer can notice your work. Since not all contractors service controllers and

The most common pool heater issue is related to water flow (though temperature sensors and capacitors present problems quite often). In many cases, installing a pool heater with a bypass valve. When the valve is not in use, the water can bypass the heater. However, issues with the bypass can lead to low water pressure. The water pressure switch can usually stop the pool heater whenever it detects a change in pressure due to a flow issue. When dealing with these problems, you need to know the flow direction, basic valve operation, and what to expect when looking at a pool and spa with water flow.

The pool will often have two drains, and the spa will have one. The drains go back to the pump. Water flows straight up the pump and to the filter. To access the pump, take the filter cap off and access the filter. Take the filter off and see how the water runs. If the pool heater works fine, then you likely had a filter problem.

So, the water goes from the bottom of the pool and into the sight glass of the pump. Beyond the pump, you have the heater. Out of the heater, the water will go to the bypass valve or another protective component before the chlorinator. Then, there is a three-way valve that goes into the ground and feeds the jets of the spa or pool through valves. There are both return and supply valves. Supply valves supply the pump (like the return in A/C), and return valves supply the pool jets with water (like the supply in the A/C).

Pools also have a skimmer, which draws debris from the very top of the water. If the water level goes down, the skimmer will only draw air, which also indicates an issue. Very rarely will you turn a dial to fix the issue, but this is one of those cases.

You can also see wire issues in the controls that have been poorly installed or misused. These issues include broken wire connections (overtightened) or torn-up wires between the heater and the control system. Don’t stop yourself short of fixing a problem area for the customer just because your company may not specialize in controls; these types of controls issues are easy to fix.