CenterPoint Energy

Gas heat without a gas furnace

Combo-heaters reduce the installation cost of gas and don’t require furnace flue venting, combustion air or gas piping. When a combo-heater is connected to an adequately sized natural gas water heater, the water heater becomes a dual function appliance that can provide comfortable, efficient space heating as well as hot water for domestic use.

How does it work?
When space heating is needed, the wall thermostat energizes a small pump which circulates hot water from the water heater to the hot water coil in the combo-heater. As the fan motor forces cool return air from the home over the hot water coil, the air absorbs heat from the hot water and this warm air is then circulated throughout the duct system and into the home.

What are the benefits?

  • High efficiency – Using a combo-heating system saves energy that would normally be lost when using a gas furnace. Laboratory and field tests have also proven that water heater standby losses are reduced when the water heater is operated more frequently.

  • Low maintenance – Combo-heaters are simple and uncomplicated compared to heat pumps and high-efficiency gas furnaces.

  • Consistent, comfortable heat – As long as hot water is available, combo heaters will provide warm air no matter what the temperature is outside. Homeowners report being much more comfortable with hydronic heat than with other space heating systems, such as heat pumps.

  • Extends water heater tank life – By circulating water through the water heater more frequently, sediment build-up is reduced, corrosion is minimized and the life of the water heater tank is extended.

Where do I go to learn more?


First Co