How to increase geothermal water temperature in bath

[davidwie]

I have a geothermal system for my heating, air, and hot water.

The hot water temperature can only be brought up to 115 degrees F which is not hot enough for the wife to take a bath. I am building a new master bath with a jacuzzi tub and am looking for ideas on how to increase the water temperature for the jacuzzi. It only needs around 20 degree rise.

What are your thoughts? Maybe an electric tankless heater? Can you recommend a small but efficient one?

Thanks!
David

 

[Jimbo]

I don't know how to fix your geothermal. But in terms of temparature, you may be off a little. According to Rheem's safety instructions, temperature of 120º can cause BURNS in about 5 minutes. 115º may not cause burns, but that is a VERY hot bath! But if your temp is about that, you would have to fill with all hot to get it to her liking, and maybe the supply temp is falling off. Let's wait for some knowledgeable folks to chime in on that issuel.

 

[Sponsor]

 

[davidwie]

I am probably off on the temperatures then. Let's just assume I need a 20 degree rise for the bath. What are the suggested options?

 

[JohnjH2o1]

Some jacuzzi tubs have a built in heater that can increase the water temperature to your liking. It works similar to a hot tub as the pump moves the water through a small heating element.

John

 

[hj]

heater

The Jacuzzi heaters are specified to only "maintain" temperature, not raise it. You have to satisfy both the temperature rise AND the volume of the tub. A "small" electric heater is not going to do the job.

 

[Drick]

Actually you may be able to get away with an electric tankless since your only looking for a small temperature rise. They need a serious amount of power though and unless you existing water heater or water piping to the jacuzzi is near the electric service the wiring can cost almost as much as the heater! Ideally you would want to add it just to the Jacuzzi hot water piping, but you could turn it on and off as needed.

You would need to check the specs on the tankless heaters to be sure they can raise the water to the temp you need and still maintain a reasonable GPM flow.

And as has already been pointed out the water temps you mentioned are incorrect. You need to determine your existing water temp and what your target temp is so you will know the amount of temp rise you are looking for.

-rick

 

[davidwie]

Thank you for your responses. I will look at the tankless option and make sure the GPM will work at the temperature rise I need. I'll connect it only to the Jacuzzi to save on energy costs.