Pros & Cons of Pool Heating in Ontario?

Aug 13, 2013
Ontario Canada
About 5 years ago I installed solar heating to our pool which is barely OK for us in mid-summer when the heat is intense in South West Ontario Canada but, in spring and fall when it's not as hot & the days are shorter it doesn't cut it. The highest we get is in the 82F range in summer so not that great.We have quite a bit of shade & I have a solar blanket on always but the kicker here in Ontario is that our power is the most expensive and we are on time-of-use pricing so in summer the time you want to run through the panels is at the most expensive time of the day at 18c/kwh. During off peak/mid peak we are at 8.7/13.2c/kwh. But our natural gas is reasonable. Would it be cheaper and make the pool more comfortable with a natural gas heater. We have an 18x36 kidney shape with an 8' deep end and a 3' shallow end. If so what size heater would we need? It would be nice to get a full season out of our pool for a change as it is so short to start with.
Thanks in advance.


In The Industry
Apr 5, 2017
If you paid attention to your gas heater and only used it it won't be bad. Use it when the solar can't get your pool temp high enough. Be warned though, leave it on unnoticed or your kids want the temp to be 90 and you are in for a big bill.


TFP Expert
Apr 29, 2016
Quaker Hill, CT
A variable speed pump could cut down on your electric bill considerably.
Also are you using a solar controller to control your panels? A solar controller for the panels can significantly improve their performance.

A a natural gas heater to work with your solar panels for the start and end of the season could be reasonable.


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
Get the biggest gas heater that your meter and gas service can handle. It takes the same number of BTUs to heat your pool from temp A to temp B, so it osts the same to heat your pool with a 250k btu heater as it does to heat it with a 400k btu hewter. It just takes longer with a smaller heater. But, if your gas service can't accommodate a 400k btu heater it could be expensive to upgrade your gas service.

I agree that a solar controller will make your solar work better and a variable speed pump could save you money.