Can I put a stronger heater in my HotSprings Grandee?

[richierich]

It's awesome that you were able to do what you wanted. Enjoy your upgraded Grandee.

[bud16415]

It is awesome you got it the way you want it.

The part I can’t figure out is why you weren’t building heat when it was in the 40’s. We have a Caldara Geneva also built by Watkins and it is 50 amp with a 20/30 subpanel and I’m pretty sure the 20 is the heat side.

We live in northern PA and we got as low as -30f last year and the tub maintained temp. we were not in it those nights but often are in it in the single digits. Over the weekend we were in about an hour with the water temp at 103 and it was 10f outside and it lost no water temp.

All’s well that ends well though. I have about a 50’ run to the subpanel #6 and then 16’ #8 to the tub. I wonder what your lengths were and if the old wire was dropping some voltage for you?   

[JacuzziJack]

Great posts, thanks for sharing your solution!

[dlleno]

some great info here -- I also own a 2013 grandee and find that for extended soaks in cold weather, the 4kw heater is insufficient.  the 30A side runs the jets, and since Watkins is greatly motivated to use inexpensive, readily available 50A hot tub disconnects, the 4KW heater is used.  they wanted to stay at 50A to keep things simple, electrically, but there's no reason one can't wire it up for use with the watkins 6kw heater. 

I'm grateful for the info shared here, and it's exactly right:  put in the watkins heater, make sure the wire sizes are sufficient, make sure your sub panel is rated for at least 60A, and all the applicable electrical codes are met, and voila.  I would only add that the wiring TO the sub-panel needs to be sufficient as well.  for example, in my last house I had a 100A subpanel and 100A rated wires from the meter.  I could have easily wired my grandee for the 30A heater.

the standard sales talk and under-informed will say that it won't make a difference but they fail to realize that a 50% increase in power to heating the water is a tremendous noticeable difference.  I'm going to upgrade mine when I get a chance!

great idea and thanks again for posting. 

[mpkelley20]

At what point will most hot tubs have difficulty maintaining temps?  It has been getting brutally cold here in MA and I went into my tub last night with outside temps in the high 20's.  My tub was set at 100 and it maintained that temp for the 25 minutes I was in it.

I did turn the temp to 103 but the temp never made it above 100 while I was in it.  So it appeared that 28 degrees or so is a good starting point for temps that make it hard for my hot tub to heat the water beyond the current temp.

Just curious.  I have a Marquis Promise two pump spa.

[bud16415]

I haven’t only once or twice turned the temp up when I was in the tub. I have had guests that asked for it to be dropped a degree or two when we were in. If it is 10 f outside and I want to take a soak after dinner and I know the tub is on 101 I turn it up to 103 at least an hour or two prior to getting in. My Caldera has had no problem holding 103 for the length of my soak at zero F and it is just a 20amp heat source. Asking it to warm the water with the cover off and the jets going is a much larger job IMO and at zero outside I would expect if I got in 100f water it would still be 100f when I got out regardless what I changed the setting to. Maintaining is much different than maintaining and raising the temp at the same time.

I judge my tubs ability to hold water temp without adding much heat by watching the cover and the outside. I have never seen any sign of snow melting on top or any such heat loos out the sides. I think 20 amps  is more than enough for any well insulated tub to maintain any temp well below zero F outside. We have been in the tub when it was sub zero out and to be honest at that temp if the tub is 104 and with a stocking cap on 15 to 20 minutes is a nice soak time. If it did drop to 103 during that time I wouldn’t notice. Now if it is a nice calm night 32f and the tub is 102 with friends we have soaked for a couple hours before with people getting in and out a few times.

For me with anticipation I don’t think I need more power and we live in one of the coldest places in the country.  It is great the OP found a solution that works for him as well.

[Hottubguy]

At what point will most hot tubs have difficulty maintaining temps?  It has been getting brutally cold here in MA and I went into my tub last night with outside temps in the high 20's.  My tub was set at 100 and it maintained that temp for the 25 minutes I was in it.

I did turn the temp to 103 but the temp never made it above 100 while I was in it.  So it appeared that 28 degrees or so is a good starting point for temps that make it hard for my hot tub to heat the water beyond the current temp.

Just curious.  I have a Marquis Promise two pump spa.

I keep my Marquis Resort at 102 and it maintains it in the cold weather. If I turn it up the temp doesn't rise on it until I shut the cover.