"Jeremiah Wright" wrote in message
...
On 9/11/2018 9:04 PM, catalpa wrote:
"Robert Rose" wrote in message
news
Hello,

Have a home forced hot water heating system.

snip
Are there home hot water heating systems that are not forced, that is, do
not use a pump?


http://www.oldhouseweb.com/how-to-ad...-heating.shtml


Thanks for the link. Don't think too many people use gravity hot water these
days. Same principle as gravity hot air, but much more complicated.