Pond Heater

[Peto77]

I am thinking about buying a pond heater as an emergency heater if the spa heater breaks or if there is a power failure. They run off 120v so you can use a generator. Sizes range from 200-1500 watts. Seems like a good backup plan to prevent freezing but I am wondering if there is anyone with experience out there.

Thanks

[HotSpringGuy]

I am thinking about buying a pond heater as an emergency heater if the spa heater breaks or if there is a power failure. They run off 120v so you can use a generator. Sizes range from 200-1500 watts. Seems like a good backup plan to prevent freezing but I am wondering if there is anyone with experience out there.

Thanks

Sounds like it could work to move water and keep the tub from freezing, another option i have used is a cattle tank heater found

At places like fleet farm or other home inprovement type stores

[Spa_Guru]

Most spa pumps have a 3/8" plug in their wet end designed as either a drain plug or a bleed valve, I would plumb to that (or both if you have two pumps)as my suction, and plumb to any available jet air line as my exit, and put in a shutoff valve so when I'm not using it it will not screw up the dynamics of jet air flo.

[Dnepr Dave]

Before you buy a heater think about how well insulated your spa is and how long you expect to be without power. A couple of years ago, we were without power for a week, with temperatures in the twenties and our hot tub cooled down to about 80 degrees F.

Dave

[Spa_Guru]

Before you buy a heater think about how well insulated your spa is and how long you expect to be without power. A couple of years ago, we were without power for a week, with temperatures in the twenties and our hot tub cooled down to about 80 degrees F.

Dave

Equipment freezes long before the rest of the tub.

In a power outage I would immediately duct tape my cabinet vents.

[Roger]

Before you buy a heater think about how well insulated your spa is and how long you expect to be without power. A couple of years ago, we were without power for a week, with temperatures in the twenties and our hot tub cooled down to about 80 degrees F.

Dave

Equipment freezes long before the rest of the tub.

In a power outage I would immediately duct tape my cabinet vents.

Ive put a trouble light in a failed tub and it didn't freeze for almost a week in 10 degree temp at night and 25 daytime. But during power outages in Northern Minnesota your worry is always heat in your house first to survive and when you have that tackled the power comes back on! I have been here 54 years and never seen the power off during the dead of winter for more than a few hours. I have seen it off for a few days in the early winter and spring because of ice storms. But 40-50 during the day, and night time lows in the 30's

[spatech (the unreal one)]

I am thinking about buying a pond heater as an emergency heater if the spa heater breaks or if there is a power failure. They run off 120v so you can use a generator. Sizes range from 200-1500 watts. Seems like a good backup plan to prevent freezing but I am wondering if there is anyone with experience out there.

Thanks

Besides the trouble light already mentioned which is typically all you need, for spas that have a circ pump you could just disconnect it and run it off the generator. The flow form the circ pump along with the heat it gives off would be all you need and you'd avoid buying a pond heater that may sit unused for years (unless you have a pond too in which case go for it).

[Bob Sanders]

Besides the trouble light already mentioned which is typically all you need, for spas that have a circ pump you could just disconnect it and run it off the generator. The flow form the circ pump along with the heat it gives off would be all you need and you'd avoid buying a pond heater that may sit unused for years (unless you have a pond too in which case go for it).

That would depend COMPLETELY on what neck of the woods you live in. I live In Manitoba (Canada) where it can get down to -40 (and that's just air temp with no wind chill). I seriously doubt a trouble light and heat from the circ pump would even be CLOSE to being enough in an extended outage.

[spatech (the unreal one)]

Besides the trouble light already mentioned which is typically all you need, for spas that have a circ pump you could just disconnect it and run it off the generator. The flow form the circ pump along with the heat it gives off would be all you need and you'd avoid buying a pond heater that may sit unused for years (unless you have a pond too in which case go for it).

That would depend COMPLETELY on what neck of the woods you live in. I live In Manitoba (Canada) where it can get down to -40 (and that's just air temp with no wind chill). I seriously doubt a trouble light and heat from the circ pump would even be CLOSE to being enough in an extended outage.

Even in your situation with those temps a trouble light and circ pump running off a generator would be fine for a couple days because they really are effective. Of course if you're talking about those temps and losing power for an extended period of time (like 4+ days) then you be best adding teh pond heater to the mix.

[Bob Sanders]

Even in your situation with those temps a trouble light and circ pump running off a generator would be fine for a couple days because they really are effective. Of course if you're talking about those temps and losing power for an extended period of time (like 4+ days) then you be best adding teh pond heater to the mix.

Sorry... don't wish to offend... but no.

I've lived in these conditions for better than 30 years and I'm going to tell you right now... things lose heat FAST at -40. In fact running the pump would probably be the WORST thing you could do under power outage conditions at -40. You need to conserve heat as much as possible and that conservation comes in the form of mass. The larger the mass (particularly an undisturbed mass) then the longer the heat will last.

Do yourself a little experiment and fill the sink with hot water... put your arm in it. Take note that the water feels quite hot at first but then seems to get a bit cooler after a minute. Shake the arm up in the water and it feels hot again. This is all caused by a thin layer of water immediately surrounding your arm which cools to approximately the temperature of your arm. That thin layer is now acting as insulation from the rest of the water. Disturb that layer (by shaking your arm) and you now feel the actual temperature of the water again. Wetsuits in fact work on this basis. They trap a thin layer of water against your body which warms and acts as insulation from the rest of the cold water.

Now if you reverse this ideology and apply it to a hot tub sitting in the cold you can easily see how water in motion will lose heat faster.

As for heat from the circ pump... pretty negligible at -40. It takes a small 4 cylinder car about 1/2 an hour to start throwing enough heat to even defrost the windshield. In fact at -40 if you leave a small car unplugged for more than 8 hours (for those who don't know... we have block heaters which are electric heaters that you plug in to keep the engine block warm), it probably won't even start. And those interior car warmers... we don't even bother using them here. Even the 1500 watt ones have virtually no effect on keeping the inside of your car warm..... too big a space for 1500 watts to handle at these temps. They do however work in smaller spaces. They're used at the airports quite often on small planes though. They throw a blanket over the nose (the motor) and throw one in the engine compartment. My guess is that they would work on ho tubs too.

Now you do generate some heat by moving the water within the wet end itself (pressurizing water will generate heat) but again it's pretty negligible

No... my guess with average tub insulation and no heat applied you have about 6 to 10 hours before you start freezing up the lower extremities of the tub. Now true...you can extend that by running the pump... but then you're cooling the entire mass of water that much faster and risk freezing up much more.

[spatech (the unreal one)]

Even in your situation with those temps a trouble light and circ pump running off a generator would be fine for a couple days because they really are effective. Of course if you're talking about those temps and losing power for an extended period of time (like 4+ days) then you be best adding teh pond heater to the mix.

Sorry... don't wish to offend... but no.

I've lived in these conditions for better than 30 years and I'm going to tell you right now... things lose heat FAST at -40. In fact running the pump would probably be the WORST thing you could do under power outage conditions at -40. You need to conserve heat as much as possible and that conservation comes in the form of mass. The larger the mass (particularly an undisturbed mass) then the longer the heat will last.

No offense taken and maybe I need to explain more clearly what the circ pump is doing for you. The purpose is not to heat up the mass of water because certainly leaving the main body of water alone is better for it and I probably shouldn't have even mentioned the heat the circ pump gave off because that threw off my message. What the circ pump does is stop the water in the equipment compartment from freezing. It’s those water lines that will freeze LONG before any of the ones that are fully insulated. Its also why you add the trouble light in the equipment compartment. So hooking up your circ pump and running it 24/7 is definitely a wise thing to do to stop the plumbing in the equipment compartment from freezing which is your first line of defense.

[Bob Sanders]

Well... as stated, running the pump will surely extend the time needed before additional heat is required. But that heat is not free. It is coming from a mass of water in which you are trying to conserve. As for a trouble light, once again pretty much useless at -40. I'm not sure you appreciate how cold -40 is. Picture having to adjust your rear view mirror several times because your body wieght is not enough to make the usual dent in your seat, then the seat starts warming. Picture a dashboard knob snapping off in you hand because it's so brittle. Picture your car stereo with absolutely no bass because the woofers refuse to move. Try and imagine your car with absolutely no suspension because it's all frozen up.

No... sorry... a trouble light isn't going to do squat.

[spatech (the unreal one)]

Well... as stated, running the pump will surely extend the time needed before additional heat is required. But that heat is not free. It is coming from a mass of water in which you are trying to conserve. As for a trouble light, once again pretty much useless at -40. I'm not sure you appreciate how cold -40 is. Picture having to adjust your rear view mirror several times because your body wieght is not enough to make the usual dent in your seat, then the seat starts warming. Picture a dashboard knob snapping off in you hand because it's so brittle. Picture your car stereo with absolutely no bass because the woofers refuse to move. Try and imagine your car with absolutely no suspension because it's all frozen up.

No... sorry... a trouble light isn't going to do squat.

I'm not from Canada (or Minnesota lol) but I grew up in Upstate NY and went to college a couple miles from the Canadian border in Canton NY (beer run anyone?). It may not have been the Yukon Territory but I've been through plenty of cold weather and I don't mean 15ºF. If its truly -40 then the circ/trouble light will certainly still help but I'd probably be fearful by day 3 so in such a case with super extreme lows and extended down time (its really rare to be down more than a day) then certainly the pond heater is the way to go along with running the circ pump sicne the equipment compartment plumbing is your first line of defense.

[Bob Sanders]

I'd probably be fearful by day 3 so in such a case with super extreme lows and extended down time

NY is pretty warm by comparison to Manitoba climates.

I can PROMISE you that a hot tub wouldn't last 3 days with a trouble light heating it at -40. All it would take is 24 hours for me to start gaining serious concern.

None the less... I don't plan on getting into a major debate on this. I will however tell you what I would do in such a circumstance. Given the fact that I do know heat and thermodynamics quite well and experience the climates we're speaking of every single year... I would NOT waste precious generator power on running pumps.

I would first call hydro and attempt to gain some kind of handle on how long power was going to be down for. If we're talking 3 days then I would most likely DRAIN the pool while there is still enough heat left in the water to keep the lines warm while I blow them out with compressed air. If you wait until the water temp is down to 40 degrees or so before making this decision then good luck getting the water out of the lines before it freezes.

Barring that I would run to the hardware store and buy a few bats of fiberglass insulation, and throw them on top along with plastic to keep the wind out. I would disturb the main tub water a LITTLE as possible in an attempt to conserve heat. I would pile up as much snow as I could around the base of the tub (snow is a good insulator) I would then use that precious generator power to run the largest heater it could run to keep the underside warm. I think the LAST thing in the world I would do is fire up the pump in an attempt to use it as a warming mechanism.

[Dr. Spa]

You'd use a huge amount of generator power to run the largest heater it could, rather than 65 watts or so to run the little circ pump?

I really don't think you comprehend what's being suggested...and yes, I've experienced -40

[Bob Sanders]

You'd use a huge amount of generator power to run the largest heater it could, rather than 65 watts or so to run the little circ pump?

I really don't think you comprehend what's being suggested...and yes, I've experienced -40

You seem to missing the point. You're not generating heat by running a pump (not enough to make a difference anyway), you're simply MOVING that heat and in the process, losing it faster.

[Dr. Spa]

You're missing the point. The idea here is to use minimal power, to use the heat already contained in the main body of the water, to keep the plumbing and equipment from freezing, until power is restored.

[Bob Sanders]

You're missing the point. The idea here is to use minimal power,

And here I was thinking the idea was to make sure the hot tub doesn't freeze.

No sorry... the idea here to to use what little power you have available to the best of one's ability. That "best" would be to run a heater... not simply to move water from point A to B. That might work for a few hours but over the long haul you've pretty much screwed yourself. Your water temp has dropped at a much faster rate than it would have otherwise and you now have no serious way of getting it back up.

[waterbear]

You're missing the point. The idea here is to use minimal power,

And here I was thinking the idea was to make sure the hot tub doesn't freeze.

No sorry... the idea here to to use what little power you have available to the best of one's ability. That "best" would be to run a heater... not simply to move water from point A to B. That might work for a few hours but over the long haul you've pretty much screwed yourself. Your water temp has dropped at a much faster rate than it would have otherwise and you now have no serious way of getting it back up.

I think this will clear up Mr. Sanders posts. It is from anothor thread he is posting in

You don't seem to understand that it is not my knowledge and experience that is being talked about. I've already admitted SEVERAL TIMES NOW that I have very little experience when it comes to discussing things directly related to spas.

[Bob Sanders]

I've lived in this climate for better than 30 years and therefore DO in fact have a bit more experience in this area.

[Roger]

Well... as stated, running the pump will surely extend the time needed before additional heat is required. But that heat is not free. It is coming from a mass of water in which you are trying to conserve. As for a trouble light, once again pretty much useless at -40. I'm not sure you appreciate how cold -40 is. Picture having to adjust your rear view mirror several times because your body wieght is not enough to make the usual dent in your seat, then the seat starts warming. Picture a dashboard knob snapping off in you hand because it's so brittle. Picture your car stereo with absolutely no bass because the woofers refuse to move. Try and imagine your car with absolutely no suspension because it's all frozen up.

No... sorry... a trouble light isn't going to do squat.

I dissagree...maybe you should try it. We get -40 here in Northern Minnesota and -30 is very common. A trouble light and a sealed insulated spa cabinet have saved many a tub. I use concrete curing blankets I have a spa tent and propane forced air. It is one of my specialtys here. And a trouble light in a full foam tubs equipment bay has saved plumbing many times. Your right it may not do much for very long at -40 but the warmth of the day will help and it can work for a short period of time. And the original poster was talking 20-30 above.

And I have lived in Northern Minnesota for 54 years and have some experience also. Give me the town you live in so I can get an average mean temp. I am in Duluth but out of town. The big lake can raise temp to 20 below when its 35 below away from the lake.

[Bob Sanders]

Ah yes... a Minnesota man. We drive there every so often on weekends to do some shopping. I'm in Winnipeg.... the wonderful windy Prairies.

[spatech (the unreal one)]

You're missing the point. The idea here is to use minimal power, to use the heat already contained in the main body of the water, to keep the plumbing and equipment from freezing, until power is restored.

I gave up yesterday but for those just joining this thread, typically you're fine if you just put a trouble light in your equipment compartment hooked to a generator. For more extreme circumstances you can aid that by also hooking the circ pump up to your generator as well and you'll be fine for days. Those of us saying this are doing so based on our experience with power outages in bad weather PLUS many years of spa experience so its not just a theoretical guess.

[hjames710]

Bob Sanders

"I can PROMISE you that a hot tub wouldn't last 3 days with a trouble light heating it at -40. All it would take is 24 hours for me to start gaining serious concern.

None the less... I don't plan on getting into a major debate on this. I will however tell you what I would do in such a circumstance. Given the fact that I do know heat and thermodynamics quite well and experience the climates we're speaking of every single year... I would NOT waste precious generator power on running pumps.

I would first call hydro and attempt to gain some kind of handle on how long power was going to be down for. If we're talking 3 days then I would most likely DRAIN the pool while there is still enough heat left in the water to keep the lines warm while I blow them out with compressed air. If you wait until the water temp is down to 40 degrees or so before making this decision then good luck getting the water out of the lines before it freezes.

Barring that I would run to the hardware store and buy a few bats of fiberglass insulation, and throw them on top along with plastic to keep the wind out. I would disturb the main tub water a LITTLE as possible in an attempt to conserve heat. I would pile up as much snow as I could around the base of the tub (snow is a good insulator) I would then use that precious generator power to run the largest heater it could run to keep the underside warm. I think the LAST thing in the world I would do is fire up the pump in"

Sorry, it wouldn't let me quote. Been in -40 many times before. The point of running the circ. pump is to keep the equipment from freezing. Some of your tub may be fine, but your equipment, the most expensive part would be toast, and would cause $1000's in damage. Don't know about you, but if I close the air control for my ozone, and just run the circ. pump, it won't lose heat very fast, and would be fine for a long time. And you shouldn't lose heat very fast unless you have a poorly sealing cover, which should be replaced. Most people here would use their generator on their hot tub, because it's not homemade, and they've probably invested $6,000 or better in it. Shouldn't you insulate your tub before it's -40? Maybe that would be a better idea.

And to answer the original question, yes, a pond heater would work. Just make sure to get a Heater, not a Deicer.

[Bob Sanders]

The point of running the circ. pump is to keep the equipment from freezing. Some of your tub may be fine, but your equipment, the most expensive part would be toast, and would cause $1000's in damage.

Sorry... I beg to differ. The point of the circ pump is to shift heat around. It works in conjunction with the heater. When there is no heater then what you are doing is betting the hydro will be restored before you run out of heat to move around. THAT'S pretty risky since it doesn't take oodles of heat to MAINTAIN the water... but LOTS to heat it when the entire mass is cold.

My tub is fully insulated. 6 inches on the bottom, 3.5 inches on the sides and 5.5 on the top. It also has a completely sealed vapor barrier to protect from the wind (which is where you REALLY lose heat). There is also a hollow channel around the entire tub between the insulation and the tub so that the tub can 'breath' air from the house itself.