When two gas furnaces of equal capacity are operating simultaneously and the burner flames decrease in size, what should be checked?

When two gas furnaces of equal capacity are operating simultaneously and the burner flames decrease in size, it is important to check the gas piping layout to ensure it is properly sized. In this scenario, the size and configuration of the gas piping are crucial because if the piping is too small or improperly designed, it may not be able to supply enough gas to both furnaces simultaneously. This can lead to a reduction in the flame size as each furnace struggles to receive the necessary gas flow for optimal operation.

The presence of both furnaces trying to draw gas at the same time might create a situation where the available supply is insufficient, affecting performance and efficiency. By verifying that the gas piping is adequately sized, one can determine whether it is capable of meeting the demand, ensuring that each furnace operates effectively without a decrease in flame size. Addressing any issues in the gas supply will help maintain proper combustion and heating performance for both units.