Longest life with lowest maintenace combi unit for radiant heat + DHW
Hi, I’m looking to replace and upgrade an existing open-loop radiant floor heat + DHW gas water heater in a three-story ~1200sq/ft townhouse. What design direction would you recommend – Combi Tank, Combi Boiler or Combi Tank + Boiler? I would like to decide based on:
– longest life
– lowest maintenance
Here are units I am considering – let me know if there is a superior alternative:
—Combi Boiler + Tank—
Viessmann VITODENS 222-F
Also, is it even possible to avoid fossil fuels and install a combi air-to-water heat pump? Or is the technology not mainstream yet?
—Combi Air-to-Water Heat Pump—
Thank you for your insight!