A work around for this on some tankless heaters is to use a spinning turbine in the pipe to detect that water is being used and to provide energy to ignite the gas.
Propane pilot light btu.
An average pilot light is about 1000 btu s.
Minimum for purposes of input adjustment 6 in.
Noticed that the pilot light uses a signif amount of fuel.
90 000 1 000 90 0 so your pilot light will burn 1 gallon every 90 hours.
Inlet gas pressure maximum 14 in.
90 x 5 gallons 450 hours.
The pilot orifice is a small metal piece within the pilot assembly.
Dimensions in h x w x d height includes legs 24 09 in.
450 24 hours 18 75 days.
Max btu 30 000 min btu 15 000 fuel type natural gas ignition electronic push button manifold pressure 5 in.
It regulates the amount of gas supplied to the pilot flame.
Fan ratings select models 120v 60hz 18w 0 15a.
Note that in newer tank gas water heaters the pilot light is much smaller.
You will consume slightly over a third of a gallon of propane per hour or 3 5 hours of burn time per gallon of propane.