Heater question: 250k vs 400k btus

[dawaves]

Hi everyone,

My pool and spa is relatively small at 90 linear feet and only 5.5 deep at the deepest end. I've calculated around 8500 gallons.
Is the main criteria for getting a larger btu heater the faster the heating up period? I know cost, spacing, etc are all variables as well but all things being equal, is bigger always better?
Like when does someone get a 250k btu heater over a 400k btu heater?

 

[Newdude]

Like when does someone get a 250k btu heater over a 400k btu heate

When they have 8500 gallons in sunny and warm CA.

Technically bigger is always better and a 400 will heat the same water 37.5% faster, but at some point its still overkill and I believe you are that point. In Northern Michagan you may still want the 400 to fight the weather.

 

[mknauss]

Heat up time for the water is all that it effects. Most get heaters for integrated spas, and thus, get big heaters so they heat up quick. You do need to take into consideration your existing gas meter size and cost to replace, cost for the gas line that needs to be run, etc.

 

[ajw22]

Like when does someone get a 250k btu heater over a 400k btu heater?

• When they don’t know better
• When their gas service is limited in capacity
• The difference in cost is more important then the heating speed.

 

[Rocket J Squirrel]

Like when does someone get a 250k btu heater over a 400k btu heater?

When their pool is too big to heat economically with gas and the heater is just for the spa. (Mine is 300 kBTU.)

 

[flynwill]

I am also in SoCal and have a 400k BTU Gas heater on my 6100 Gallon pool and spa, and that is what I would recommend. It means I heat the pool in a couple of hours instead of overnight, and the SPA can be ready in 20-30 minutes. The cost to run the heater will be the same. The only factor is the increased cost for the larger heater and possibly increased costs for the gas line. SoCal gas will swap your meter for a larger one for no cost if that is needed.

 

[dawaves]

Heat up time for the water is all that it effects. Most get heaters for integrated spas, and thus, get big heaters so they heat up quick. You do need to take into consideration your existing gas meter size and cost to replace, cost for the gas line that needs to be run, etc.

Thanks for the reply mk. I ran a 2" poly gas line so I can tap off of it later if I want a fire feature and/or bbq. It's probably overkill but that seems to be my mo, lol

 

[dawaves]

I am also in SoCal and have a 400k BTU Gas heater on my 6100 Gallon pool and spa, and that is what I would recommend. It means I heat the pool in a couple of hours instead of overnight, and the SPA can be ready in 20-30 minutes. The cost to run the heater will be the same. The only factor is the increased cost for the larger heater and possibly increased costs for the gas line. SoCal gas will swap your meter for a larger one for no cost if that is needed.

That makes perfect sense. Thanks flynn!