yes 400 to 450 is what you should get
Your hot water heater is not large enough.
from below the heater
a quartz heater is otherwise known as an infrared heater owing to the materials of construction being mainly quartz
It depends upon the wattage of the heater.
room heater warm by radiation
thermopile
Input pressure.
Hayward has a good electric heater. visit www.askpoolquestions.com for more information
Hayward.com has owner's manuals available for download. It's about 30 pages long so make sure you have enough paper. I downloaded mine 3/09, should still be available.
You need a orifice cleaning to remove carbon build up on the flame tube and main burners.
Not enough info. Car heater? House heater? Gas? electric? Water?
If there is a restricted air flow through a heater, yes a heater can get hot enough to start a fire.
You don't. If the heater has an electronic spark, then it doesn't have a standing pilot to light. The spark lights the pilot when there is a call for heat, which in turn lights the burners. If the heater is on and the pump is RUNNING, the heater should light automatically when the water temperature is lower than the heat setting.
At least 20"x30" or large enough to remove water heater.
The H100 has a flow rate of 20-70 gpm, if you are moving more than 70 gpm then yes, if not, then no.
If you mean "stay lit", you probably have a faulty thermocouple. This costs about $10 and a competent handyman or technician can fit it in less than an hour.
Only if you leave the burners or elements on. -If water stops, close gas line or switch off breaker for tank.