No Heat How Long Until Too Cold

rsw686 · #1 07/29/2007, 08:55 PM

So my AC Jr temp probe looks to have failed so no lights or heaters working. I can't get to the tank until tomorrow, which is 12 hours from now. The tank, 90gal with 20gal sump, should be at 80 degrees and the house is 72. The only thing running is the OceanRunner 3500 return pump and two Hydor #3 powerheads. Am I right in thinking that the wattage of the pump is comparable to a heater of that size? Does anybody know how long it takes for water to cool? Thanks.

nano_angel · #2 07/29/2007, 09:21 PM

ur tank wont get cold enuf to hurt anything u will be fine. i have a 75 and a 120 and never run heaters in them and my house ac is at 69

rsw686 · #3 07/29/2007, 09:25 PM

With your house at 69 what temp are your tanks at? Do you have multiple pumps running?

PJSEA · #4 07/29/2007, 09:28 PM

You could always raise your thermostat a little if your tank cools off too much.
Your questions cannot be answered exactly. The wattage of the pump is not equivalent to a heater that size. Pretty much the inefficiencies that result in heat being produced will go to heating up the water. Most of the "power" goes towards moving the water.
How long it takes for the tank to cool depends on numerous things: The difference in temp. between tank and air, heat production and heat removal(conduction,convection); factors affectin heat removal are thickness of glass, surface area of glass and water, air blowing across the surface of the water, etc., etc.

Just look at the tank temp. with a thermometer and see what it does over a half hour or hour. That will tell you how fast your temp. will drop. It will never go below the room temperature. In fact it will probably be a few degrees higher.

Snowboarda42 · #5 07/29/2007, 09:29 PM

If you're concerned with it, have you or a neighbor grab some tupperware and put boiling water in the tupperware and float it in the tank (or preferably the sump)

rsw686 · #6 07/29/2007, 09:34 PM

I would but I'm not at the house and can't get somebody to stop by. I can't get there until tomorrow morning so I can only watch whats going on by a camera. I'm ****ed that the AC Jr is two weeks old and malfunctioning. I was better without it. Theres a whole thread on temp probe failures. I'm just hoping I can get my money back for it.

areze · #7 07/29/2007, 10:12 PM

itll stay over 72 degrees, and that wont kill anything. I would bring it up slowly over a week or so if possible when you get back.

sucks about the temp probe, it happens

heaters fail. all you can really hope for is that it fails off and not on, which they seem to do.