The idea here is to prevent domestic water from getting contaminated by stale water that sits uncirculated in the heating system during the off season.
How to heat both my floor and sepate domestic water.
The open system uses one heat source your domestic water heater to provide both floor heating and domestic hot water.
Hot water from the boiler is circulated through radiators or a hydronic heating system to warm the ambient air.
The water heater to use with radiant floor heating should be a high efficiency unit.
The best kind is one that has a sealed combustion chamber and an external heat exchanger.
One option is to keep domestic hot water completely separate from water that s part of the heating system using a heat exchanger.
In the summer water will stagnate for the floor heating and if it mixes with your regular water it won t be good.
Normally the wood boiler is plumbed to a heat exchanger see drawing above.
The same water that ends up in your hot shower or dishwasher for example has passed through the floor first.
Even if only part of the home uses.
The traditional boiler water may also be used for domestic hot water by directing the water through a separate integrated water heating unit before routing it to a fixture such as a faucet or shower.
A dual purpose system relies on only one water heater to supply both the hot water requirements for the home and the warm water needed for the radiant floor heat.