Combustion Efficiency: 75% with a wasteful, standing pilot in both units. The water heater is particularly inefficient as it loses a lot of heat up it’s flue pipe and is poorly insulated. Such water heaters have a 5-7 year warranty.
After: (Photo #2):
To the original owner: Lifetime, stainless steel warranty.
Viessmann Vitola ECD Combustion Efficiency: 83.5%
Viessmann Verticell HG53 Indirect Fired Water Heater.
With electronic ignition, and no wasteful standing pilot lights. Note: The water heater does not have a flue and is much better insulated.