If your pool is heated with gas a heavy duty timer is not recommended. Please contact the Pool Council of Canada at (800) 879-7066 or visit www.poolcouncil.ca for more information.
Why Shouldn't I Use a Timer with my Gas Pool Heater?
Since gas pool heaters reach a much higher temperature than electric ones do, turning off the pump without any thought of the heater means the residual heat of a gas heater could damage some of the plastic pipes of fixtures. If you do have a gas heater, you need a timer sophisticated enough to be able to turn off the heater 20 minutes earlier than the pump – often known as the Fireman’s Switch.
Keep the pool’s heating and cleaning equipment clean and lubricated.