Plumbing Question - inline (on demand) water heater for tub?

WyoYote

WyoYote

New member
We've recently installed a fairly large Jacuzzi whirlpool tub, works great, only problem is, due to the large size, our 40 gal. water heater doesn't quite have enough 'ummph' to supply an adequate amount of hot water. It's a brand new nat. gas water heater, works great...but I just think the volume is not quite enough for the large tub.

EDIT - our water heater works fine, just doesn't have enough capacity to adequately add enough hot water to the tub

I'm thinking that we could install an auxiliary electric "inline" water heater to supplement the hot water line. I understand that a system like this would work on demand via a vacuum sensor...it would automatically turn on when the water is flowing. We're just trying to supplement the supply line to the tub, not the whole house. Basically, my idea is to 'heat' up the incoming hot water a notch more

I know that you can get an inline heater for the actual jacuzzi pump on the tub, but this only keeps the water that you do have in the tub warm (status quo...basically same temp that the present tub water is at), it doesn't raise the temp of the water.

My question to the plumbers is - would this be a feasible plan? Access is a-ok, as I have a fairly tall crawl space underneath the tub. I'm compentent enough to do the plumbing/wiring. I would prefer it to be a 110 volt system.

What make/brand??? Curious to hear some opinions..>THNX
 
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Just from experience, if you want to keep the water hot, go with a 220v heater (much cheaper for electricity)...When you place a couple of 90 degree bodies in 104 degree water, it cools of pretty fast..and the "in-tub" heater should have a thermostat to allow you to dictate the degree of water temperature, either through a pre-set, or a rheostat..

The in-line heater will work, but will only heat the supply water and not keep it warm....

I don't know about you, but if I'm going to soak in a jacuzzi, I don't want it to be a short term situation and the larger it is,,, the faster it will cool...

I've had both the jacuzzi and a 7 person hot tub that was outside and we used it in the winter at our B&B, with the snow falling...and had no problem keeping the water at 104 degrees..or hotter if you can stand it...
 
Or you could use the money you were saving for the heater to buy some liquid warmth in gallon size. When it gets cold, pour it in you. If you are still cold, pour in more.

You might still be cold after that, but you probably wont care. HE HE.
 
I know you said your heater is new but another option is to install a tankless heater.

Takagi is what I install here and they are great. A little on the expensive end but great.

They are not instant hot water but they are endless hot water. And you can get a high GPM model that can handle the house, the tub and the neighbors house.

I have a wife and 3 kids (2 girls) so hot water use to be in short supply around shower time. With the Takagi installed it is never an issue.

There is no tank to heat so you actually save money in the long run. Its hot water on demand if you would, when you turn a fixture on it goes on and flash heats the water until you turn it off.

If you have an issue with your plumbing currently taking forever to get hot at certain fixtures you could also looking into installing a Grundfoss recirculating pump that would at the preset times you program run hot water through the pipes so that its "instant hot" when you wanted it. I usually sell these in conjunction with each other so that people no longer have any hot water issues.

Just a thought..

Here is some info on the tankless heater:
http://www.takagi.com/index.php?product_id=38&page_id=2

They come in all different sizes, gas and propane and they even have an outdoor model in case you don't want to run new double wall flu venting. Or you can do like we usually do and just install it on the outside wall of the garage/attic and then direct vent it outside. Takes very minimul rerouting of the gas and water lines. With shark bites, aqua pex and gastite or wardflex you can reroute stuff in no time.

Here is some info on the grunfoss:

http://www.grundfos.com/Web/HomeUs.nsf/Webopslag/PAVA-53MKRN

Any plumber in your area will have information on this stuff.

Here in Arizona the RETAIL charge averages $600 and change for the grundfos installed but if you have a buddy with access to a wholesale account the pump runs $200-300 and is very simple to install.

The takagi's run around $3k installed but actually only run around $900 for the unit. Then there are additional costs associated with the flu, water and gas piping materials needed to reroute. Plus some wood for building a brace if you dont run a ground unit.

I know its an expensive solution, but it really upgrades your entire system and solves your immediate problem as well.

Food for thought really.
 
Kodiak (and the others), THNX for your replies. We really don't have an issue on the amount of hot water available for the house, we just don't have enough hot water to adequately service this large jacuzzi tub that I just put in.

What I was think was, just adding a small 'tankless' type water heater to supplement tub only...consider it more of a 'booster'. I'd hook it up to the existing hot water line going to tub, to 'superheat' the water...we'd then adjust the tub for comfort with the cold water

And...duh!...220 volt would be fine, as I forgot that I have 220v wiring very close to the tub
 
^^^^

Sounds like the light bulb went off and you got er all figured out.

Emaxx makes electric units that would handle the job your after. I see them on ebay all the time.

The smaller "point of use" heaters may be a little small to handle your tub, but I could be wrong that.

Good luck brother.
 
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