Find an Immersion heater....

[uncle Alan]

Back in The Stone ages ['40s, actually] we had a water heater you could drop in the tub & it would do a good job of heating water.

Patsy's granddaughter is getting an apartment & we regain our hottub. We usually have to boil several gallons of water until our quick recovery water heater recovers.

This tub holds probably over 100 gallons & the drop in device would surely speed up fill time.

Uncle Alan

 

[Kohai999]

Back in The Stone ages ['40s, actually] we had a water heater you could drop in the tub & it would do a good job of heating water.

Patsy's granddaughter is getting an apartment & we regain our hottub. We usually have to boil several gallons of water until our quick recovery water heater recovers.

This tub holds probably over 100 gallons & the drop in device would surely speed up fill time.

Uncle Alan

Like this?

http://www.buichurch.com/steeples/bap_acc-intro.htm

A complete self-contained thermostatically controlled water heater. Immersion parts & hanger made of stainless steel. Visual off-on switch with pilot light which indicates when heater is being energized. Completely automatic & portable with cord & plug ready for use. 6000 watt; 240 volts single phase. Requires a 220 outlet.
Model 700 Price $345.00

Construction Features

Immersion section of unit made of Incoloy or Stainless Steel.
All heat confined to the formed horizontal section for optimum heat efficiency.
Cold riser extends to the top of container where control housing is located.
3-Conductor cord set with polarized plug included for easy installation & wiring at no extra charge.
Adjustable vapor-proof thermostat control with temperature range off - 55°F to 115°F (± 3°).
Hi-Limit cut out switch set at 125°F (±4°).
Stainless steel mounting bracket also supplied for easy mounting.
Pilot light & on-off switch provided, indicates desired temperature

Best Regards,

STeven Garsson

 

[Absintheur]

If your hot water heater is aging I would just replace it with a new system that supplies unlimited hot water. I have had them in several houses and it is a true pleasure knowing you will never run out of the hot stuff no matter how many take a shower or bath. The on demand water heaters also end up saving you money over time as you are only heating water you use, not water you store.

 

[Gollnick]

Like this?

http://www.buichurch.com/steeples/bap_acc-intro.htm

RED ALERT!

Several years ago, a Pastor was killed in Texas while standing in a Baptistry heated by such a device. He reached up to adjust a microphone that was suspended above the Baptistry and wham! The heater in the Baptistry had bad internal insulation and so the water was at 240VAC. When he touched the grounded microphone, the current killed him.

The heater was not installed with a ground-fault interrupter. Such devices should never, ever be used without a GFCI.

 

[spyder10]

The heater was not installed with a ground-fault interrupter. Such devices should never, ever be used without a GFI.

Yeah the whole idea of 240v in a bathtub sounds like a very bad idea to me. If your water heater doesn't provide the amount of hot water than you should look at a new water heater. If you do decide to get one I would recommended to make sure you have a GFI (Ground Fault Interrupter) and I would not be in the tub while the unit was energized (i.e. plugged in at all, even if it is off)

 

[gadgetgeek]

boil in a bucket heater? looks like a oven element with a perforated steel jacket, or one with a float, but the floaty ones are mostly just to keep water from freezing. I've seen them at most farm supply stores, and they should be cheap, no thermostat, just 110VAC of heat. and like the other guys said, GFI is your friend

 

[Valpo Hawkeye]

I'm a licensed plumber and a certified heating/air/radiant service tech. Usually I don't care for on-demand water heaters. For retrofit they have too high of an initial cost to justify the energy savings. Factor in that they have a heat exchanger that must be flushed to maintain performance and the fact that it has more electronics that a 95%-efficient furnace, they turn me off.

However, this is one application where one might be worth it. The "unlimited" hot water thing is almost a necessity when you have a large tub. The other options are multiple water heaters or, if you have a boiler or would like a boiler, you can go with an indirect water heater that will essentially give you unlimited hot water.