Can Pumps Freeze

[bajabill]

Just wondering how do you insure the water in the pumps, heaters, and adjacent plumbing does not freeze in extreme cold temperatures.  Do people suppliment insulation around the mechanical compartment that is typically not insulated.  It seems that it is possible for this to occur if the main body of water does not require heating for a long time - such as if the water temp is high and the setting is lowered.  I think 10 hours before a filtration cycle kicks in may be enough for some ice to form.  But, history and real life experience seems to indicate that this does not happen much.

Also, 24hr circ pumps will not help if they do not move water thru all of the more exposed plumbing paths.

[Dr. Spa™ Ret.]

It seems that it is possible for this to occur if the main body of water does not require heating for a long time

Typically the temperature is measured right at the heater, not the actual water temp of the main body of the spa.

Also, 24hr circ pumps will not help if they do not move water thru all of the more exposed plumbing paths.

Actually, since the water is moving through the equipment compartment, it typically radiates out enough heat to keep things well above freezing temps.

[TwinCitiesHotSpring]

HotSpring has tubs with 24hr circ pumps and also tubs that kick on low speed to circulate and I've never seen a jet pump on a spa that is fully operational freeze in MN winters so take that for what its worth

[Hot Spring Ace]

Another thing Caldera and Hot Spring do is to put the circ pump, jet pumps and spa controls all on one breaker while the heater is on a separate breaker. If the heater ever fails to where it trips the breaker it won't shut down the entire spa so the circ pump continues to run circulating water throughout the spa. That circ being on alone should be enough unless you have an extended power outage and you certainly can turn on the main pumps as well. In Hot Spring the drain to the jet pumps is also tied to that circ pump so when the jet pumps are off and the circ pump is on a small amount of water flows through the pumps.

[Tman122]

Just wondering how do you insure the water in the pumps, heaters, and adjacent plumbing does not freeze in extreme cold temperatures.  Do people suppliment insulation around the mechanical compartment that is typically not insulated.  It seems that it is possible for this to occur if the main body of water does not require heating for a long time - such as if the water temp is high and the setting is lowered.  I think 10 hours before a filtration cycle kicks in may be enough for some ice to form.  But, history and real life experience seems to indicate that this does not happen much.

Also, 24hr circ pumps will not help if they do not move water thru all of the more exposed plumbing paths.

Most tubs even the inexpensive ones have what's call a freeze protection sensor. Regardless of the temp of the main body of water this sensor located down at the pumps in the incoming water line turns the pump on at like 40 degrees or something.

[bajabill]

Thanks,  some good info.

I agree that I overlooked the benifit of warm water continually in some of the plumbing will provide some abient heat to the compartment.

I was not too receptive to the heat sensor being at the heater initially due to the likelyhood of short cycling the pumps once the warm water was pulled into the sensor.  However, I do think use of such a sensor as described by Tman122 is ideal. 

Like I said initially, I know the systems work, just did not know how.  The perforated thin plastic wall enclosing the mechanical compartment is needed in hot weather but may not be ideal for the cold weather.