Have you verified propane will work on stove? This will tell you if there is propane actually available.
The next check would be to see if voltage is getting to the water heater gas valve. Since the spark is working the next step in the process is for the gas valve to open. If voltage is across the valve terminals but it is not opening, the valve is bad, provided there is propane at the unit. I am assuming the gas shut off valve at the water heater, if there is one, is in the correct position.
Retired electronic technician (45 years in the field)
2017 Greyhawk 29W
solar & many other mods
wife (maybe I should have given her top billing)