Keeping pool water warm: Best practices to ensure long heater life

Condensation

Propane and natural gas, when burned, produce water as a byproduct. If the heat exchanger is too ‘cool’ the humid flue gases will condense on the fins of the heater. Condensation on the heat exchanger causes carbon to adhere to it. The condensate collects, then drops on to the burners. The combustion is then compromised as ‘raining’ condensate that interferes with the flame pattern.

This poor combustion turns into ‘soot,’ which collects on the fins and, as a result, causes the flue gasses to be impeded.

The condensation not only causes inefficiencies in heater functionality, but also causes oxidation on copper from low return water temperatures.

Brief periods of condensation on start-up is normal for most pool heaters. In fact, all category I and III pool water heaters will condense if allowed to send very low return water into the heat exchanger. However, adding airborne chemicals to condensate on heat exchanger coils will cause the unit to fail more quickly. As mentioned earlier, ‘sooting’ is often the first sign of a problem, but is often ignored. In fact, some service technicians who have not been trained properly may place jumpers on safety devices instead of paying attention to the ‘sooting’ that occurs.

Soot formation on heat exchanger tubes

There are several items to look for to identify soot formation on heat exchanger tubes. The first contributor to the problem is low gas pressure. The heater needs a 28 cm (11 in.) wc for propane gas and a 10-cm (4-in.) wc for natural gas. The pressure of the gas should be inspected while the burners are lit.

Soot can also form when there is too much water flow through the heater. To remedy this, a high flow modulator or a manual bypass valve should be installed. Obstruction of the burners by some foreign matter can also be a problem; therefore, it is important to remove, inspect, and clean all burners.

Maintenance program

All aquatic facilities should establish a comprehensive maintenance program for the equipment room, which must include a specific action plan for heaters, as well as the pumps and filtration systems used on pools and other water features.

It is also a good idea to keep additional parts on hand just in case an aquatic facility needs to get a heater up and running immediately. Having access to items such as pilot assemblies, orifice parts for burners, and even a gas valve can come in handy during a time of need. Most facility operators would also agree that it is wise to post the phone number of a nearby service company directly on the heater in for emergencies. Avoiding heater problems this winter is important to all aquatic facility managers and, often times, the simplest best practices are the ones that keep pools running smoothly at all times.

Mike Fowler is the commercial sales manager for Pentair in Sanford, N.C. He has been with the company since 1992, starting his career in the technical services department at Purex Pool Products. Fowler has held many managerial roles within the company, including marketing, accounting, and products. He can be reached via e-mail at mike.fowler@pentair.com.