questions about hot tub in winter

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  #1  
Old 10-27-04, 08:51 AM
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questions about hot tub in winter

Hi,

I have a beach comber hot tub with an external pump (2 speeds)
I just installed a 240V digital timer on it. I am happy that i can now run it for a set time everyday.

My question is regarding timing in the cold winter. We dont really use it much during the week. usually just Thurs eve, Fri eve and Sat and Sun.

Lets say that i only run the pump for 3-4 hours during the weekdays. If the hot tub is keeping the water at 102 C would the external lines that go to the pump have the possibility of freezing?

Thanks,

Jason
 
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  #2  
Old 10-29-04, 08:31 AM
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Up there in the great white north I'm sure that uninsulated and exposed pipes might freeze. If you insulated the pipes well and had your pump run for a few minutes every hour or so would really help.

My big concern would be a pipe or the pump freezing and the timer tells it to turn on. You might (probably) burn up the motor if it tries to run when the impeller is frozen in place.
 
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Old 11-01-04, 05:25 AM
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Heating without the pump running?

An insulated hot tub retains the heat that has been invested in the water located within the insulation covering. It's not clear how far external the pump (and water lines between the pump and spa) is separated from the spa.
All of my equipment is within the spa cabinet, so it's not totally exposed to freezing weather.
I have electric heat, so a small recirculating pump runs continuously to circulate the heated water between the heater and the spa itself.

Without the pump running (which would flow warmed water through it) and without an external heat source (bury it underground maybe?) what prevents the water in the pump from assuming the outdoor temperature, even with insulation around it. That's not much thermal mass in the pump itself.
 
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Old 11-01-04, 03:21 PM
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IBM: You insulate the pipes and pump to slow down the heat loss from them, and the pump needs to run every hour or so to replenish the heat that is lost.

I've got water pipes insulated with 2" of foam and they can go 4+ hours in single digit temperatures without freezing. The water comes out of the ground at about 50 degrees and it's a 3/4" pipe so it's thermal mass is smaller than most spa plumbing.
 
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Old 11-01-04, 04:53 PM
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Hello Blue,

I also have a Beach Comber 750 with external 2 external pumps and a circulator pump. Not to worry it will not freeze unless of coarse there is a long power failure.

Which model do you have and does it have a circulator or do you use the main pump to circulate.
 
  #6  
Old 11-04-04, 07:56 AM
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Hi guys,

Thanks for your responses.

I am not sure of the model of tub, it is about ~10 years old. The pump is housed under the step to get into the tub (right in front of the unit) there are 2 small doors that open to adjust heat and turn on and off pump. There is only one motor that has 2 speeds. It heats well though right now i set the timer for only 2 hours a day (mon - wed) and it is always at 103c when i check it. There is a 2-3" hose that goes from the motor to the tub ~ 2-3 feet long in and out...
I am thinking of wrapping something around the hose and maybe insulating the step as well.

Thanks again.

J
 
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Old 11-04-04, 02:34 PM
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If you don't like what you've heard so far, they sell electric heat tape for keeping pipes from freezing. It is basically an electric blanket for your pipes. The heat tape usually has a built in thermostat that turns it on around 40 degrees and it provides just enough heat to keep the pipe from freezing. They also make long wire versions to put on the roof of your house to prevent ice daming and to keep the gutters and downspouts flowing.
 
  #8  
Old 12-27-04, 07:59 PM
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not being from an area that snows , I don't have a lot of imput re wrapping pipes, however I have had a lot of experience with 2 speed pumps and automated controls, on all the automated controls Ive installed / repaired all manufactures build in freeze controls, this is a temperature sensor , that when the temperature falls to freeze conditions it turns the pump or pumps on for a period of time and repeats this procedure over & over until the sensor detects a desireable rise in temp.

I believe Grainger carries an aftermarket set up or make your own via / relays to the pumps if your experienced enough.

or the fact that you have a 2 speed pump , on any given day when you know in advance the temps. may drop to freezing let the spa run on low all night a 2.0 hp 2 speedd pump 220 v the low side runs @ 1750 rpm and is a 1/4 hp pump. very efficient amps would be 2.0 apx.


steve
 
  #9  
Old 01-09-05, 05:53 AM
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Keep the water moving

Heater on or off, moving water has a LOT harder time freezing than water that sits still. If you can keep the water circulating, it wont really matter about the heat. Just another option.
 
  #10  
Old 02-09-05, 08:23 AM
Jocus
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What would happen with a power failure with temperatures around zero or so? We have snow storms where the power fails for about 12 hours at times.

Also, would anyone know an estimated cost of running a hot tub in the winter in Canada?
 
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