An indirect water heater uses your home’s boiler as the heat source, storing hot water in a separate insulated tank.
Think of an indirect tank as a big Yeti cup. The boiler that heats your radiators would have a separate zone that sends hot water to a heating element around the tank. That heat transfers to your hot water supply which sits in the middle part of the tank. They’re extremely efficient because they are very well insulated. They don’t lose heat nearly as fast as a standard tanked water heater.Installed correctly with the right pipe and pump sizes, they can rival a tankless water heater as an almost endless supply of hot water because of the high “recovery rate” or rate in which it can produce new hot water. Indirect Tank water heaters are a favorite of ours for homes that have a hot water radiant system heating their home.
These units are beasts. They are extremely durable with no corrosive parts and therefore last longer than standard tanked water heaters.
If you are considering a tankless water heater for the endless hot water but are a little nervous about flying without a parachute (that is, no stored hot water if something goes wrong), this can be a good fit. The output of hot water is similar.
The main thing to keep in mind is that an indirect tank requires a heating source, usually a hot water boiler (standard efficiency or high efficiency). It’s a great item to consider when replacing your boiler as an option for domestic hot water.
