Attic mounted pool heater?

How big is the heater compared to pool size? Does the heater face south? Do you use a cover?

 

It's a 400k BTU propane heater. It raises the ****er temp about 1 degree an hour in a 36k gallon pool. Now obviously it is only burning fuel when it is actually making heat. I want to keep the gas heater as a back-up to the solar since 2 weeks of rain and the pool would still be cold for a few days at least after the sun can back out I'd think.

A heat pump type heater would be about 1/3 the cost to run, but costs about double to buy and only has about 1/4 the BTU rating so it would need to be switched on WAY before I wanted to use the pool. These heaters work great if they are left on all the time, but not so good as a suppliment or on demand system.

 

The heater isn't broken, 5gal/hr is the spec.

Natural gas costs about 1/2 of what propane and your heater may be a higher effiency unit than mine so that helps. Warming the water up to temp takes a lot of heat, keeping it warm isn't nearly as bad so that is part of the differennce too. I am surprise you are able to keep that much water that warm for that price....what state or what average winter daytime temp are we talking about?

 

That bill seems about right for NC. In the warmer weather more of the heat loss (about 90%) is from evaporation. In the winter evaporation is a much smaller player becasue cold air doesn't hold much water so it basically just conduction from the water to the air and air isn't a very good conductor. If you pool is somewhat blocked from the wind you might only loss a few degrees per day and that would be right in line with the bill you got....maybe.