The water heater condensation is not leaking. Condensation is a regular occurrence that happens in gas water heating appliances when working. How to recognize condensation in water heaters, what to do, can you prevent it, and how to troubleshoot problems?
When natural or propane gas burns in gas water heaters, a great amount of moisture in products of combustion are released. So, when the water vapor is chilled below the dew point, water heater condensation occurs. The dew point is the temperature at which water vapor turns into the liquid state, called condensate.
When the main gas burner is on, the heater produces hot flue gases, which turn into condensate upon contacting colder surfaces. One of the situations where the condensation might happen is when the piping is cooled by the low incoming water temperature that flows through.
To troubleshoot the water heater condensation, you have to recognize the symptoms first and which part of the unit condensates. Below are the main reasons for condensation:
Because of the suddenness and the amount of condensate, this problem might be diagnosed as leaking. Keep in mind that one-half of the gallon of condensate during every hour of operation is typical for residential heaters. It takes 1-2 hours for the tank to warm up and condensation to disappear.
Since the new high efficient heaters and Energy Star models utilize the powerful gas burner and combining it with the latest technology to extract even more heat from the flues and flames will condensate more than the older heaters that use less energy.
One of the solutions when troubleshooting condensation in the heater is good venting so the gas appliances can operate efficiently and vent the products of combustion together with the water vapor properly.
As the cooler flue gases are part of the condensation problem, the suggestion is to raise the supply air temperature and increase the stored water temperature or size of the tank.
A suitable metal drain pan, at least 2" wider than the heater, should be installed under the heater to collect the condensate and not damage the area.
Condensing water heaters such as tank-type model Vertex from AO Smith, or tankless type from Rinnai, Noritz, or Navien, produce acidic condensate (pH level is 2-3) can cause corrosion or damages to the drain and sewer system.
When you buy the neutralizer kit and install it on the water heater, the condensate is treated adequately for safe disposal into the drain. The drain should be close to the unit; the pipe should provide a slope for the free flow or, if it is needed, have the condensate pump installed.
Ensure that the condensate flow is free and clear of debris and the drain does not allow backflow through the hose. If the condensate backups into the water heater, an error code will flash, for example, a code "29" on the Noritz NRCP model. This is important, especially during the winter and freezing days.
Almost all water heaters have some sort of condensation, if not due to improper unit work, then due to increased moisture in the air. And controlling the moisture is not an easy job. In the case of normal condensation, it is better to accept the fact. I would call a plumber only if there is excessive condensation as it might cause premature tank corrosion and corrosion of heating elements and contacts.