Can a gas hot hose heating system be switched to propane? What desires to be done?

Vacuum cleaner / time to buy another one?
only if it is a hot hose down heater for mobile homes may it be converted. the will be a pod attached to the gas valve which will enjoy the conversion kit. if it is a standard gas river heater next no. you will need to buy a brand new one.
What are the biggest culprits of warmness loss...

A/C Unit - Per Contractor, delivery high-ranking pressure...
"Can"? Yes, but YOU can't do it legitimately, I question why you would want to do it.

You would involve at least a trial orifice and maybe a different pilot. On furnaces we lock out the natural gas regulator because propane runs bad the regulator on the tank. But I do not judge that option is available for wet heaters. So it may need a hot gas valve...or not. Dunno.

Conversions are supposed to be ONLY done by ethnic group with a gas license, due to risk. So mostly the propane supplier's techs do it since they need to check the tank's regulator as economically.
Does the hose contained by toilets/baths/sinks on the...
Answers:    If its a mobile home type its definitely convertible, newly turn the gas control regulator adjustment to LP and change the orifice for the major burner to an LP orifice and also the pilot orifice.
Most other water stove controls are not convertible and would require a new gas control (expensive). The orifices of coarse could be changed.