Fill Hot Tub With Hot or Cold Water?

[tootsie]

I 100% agree with brewman on water supply.

I should have stated we are on well water, and were concerned before we purchased the tub, if the pump and the well would be able to handle it, that's why we checked for alternatives in case there were problems.

[rfraboni]

I used the think the same thing as far as volume but I would be most of us use 20-50 gallons per shower, and more if we take a hot bath.  So for the volume of a few baths you are able to have a nice hot tub.

IF you are drought stricken at the moment it may be another issue.

[Chas]

If your spa is delivered during the winter months, I would have the electrician turn on the spa for a few seconds (then shut it back off) just to make sure his work is correct.   Then start filling the spa.  

I would absolutely, positively NOT do this. See my post above.

Repeat: DO NOT do this. Fill the thing before you power it up.

[clayfiregrrl]

Wow, thanks for all of the great info and responses!!  That all helps a lot.  I guess I was thinking it could take a day or so to fill up and then another day or two to heat and then god knows how many days to chemically balance, so couldn't figure out how to coordinate with the electrician (since I was thinking it could take up to a week to fill/heat/balance).  I am glad to hear it is all a lot easier and faster than I thought!  

We definitely won't be calling the FD, will wait till the electrician comes before filling in case we have to move the tub (a distinct possibility), then will be sure it is filled (with cold water from our outside tap) before powering it up, testing the pumps, etc., following the sequence outlined here.  

Thanks again!!!

Dorie

PS -- Our hot tub (HS/TR Caspian) was delivered last week and is sitting on our deck...the electrician is scheduled to be here one week from today...and we use city water (live in Ann Arbor, MI).   So if the electrician finishes by noon next Monday, perhaps we can be soaking in that hot tub by late Monday night or Tuesday night?  Woo hoo!!!!

[Brewman]

Our spa (500 gallons) takes less than an hour to fill from the garden hose.  So even if you have slow water, you should be able to fill in a few hours.  
Allow maybe an hour for each 4 or 5 degree temperature increase.  
So maybe 8 hours to get to temps, so it's entirely possible you'd be ready for your first soak that same evening, for sure the next morning.

[Backpains]

I have a 300 gallon spa. It takes exactly 30 min to drain it with 5 syphoning hoses in and exactly 30 min to fill it with the outside spicot going full blast, by the time it's filled the temp is 59 degrees. It takes 5 hours to heat it to 100 degrees. I've not thought of doing the fill from the inside hot water tap but, I will say hubby has brought out 5 gallon buckets to the hot tub with scalding water and it hasn't bothered anything he just makes sure it's evenly distributed so you might want to think of doing it that way instead if your tub isn't far from your door.

[Brewman]

Wonder how much that helps?  
With most residential water heaters holding 40 gallons,  and a few 50 gallons, you'd be putting 40 gallons of hot water in with 250 gallons of cold water.
Not sure what the temperature would equalize to, but maybe you'd gain 10 or 15 degrees?  
Just curious.

[Ruby]

I thought I read here not too long ago that one of the reasons you should't fill with hot water was because of the sediment at the bottom of the water heater possibly ending up in the tub.  I thought it was good reasoning so I quit doing it.  Since I stopped, I haven't noticed any difference in the time it takes to heat it.  

[Brewman]

If you take the water from the drain valve in the bottom of the water heater, there is a chance that the water will be full of sediment- that's exactly how you flush a water heater.  Some heaters get gunked up more than others so some water may be ok, some not.  
Some water may be full of sediment that's not readily visible, so I wouldn't chance it.
But our water heater is over 6 years old, and I don't regularly flush it out so we probably would have sediment.
 

[SerjicalStrike]

I would absolutely, positively NOT do this. See my post above.

Repeat: DO NOT do this. Fill the thing before you power it up.

Would you rather turn the tub on for 3-5seconds (wihtout turning any of the actual pumps on) with no water in it and find there is a problem  or would you rather have a tub full of cold water and then find out there is a problem?

In the winter, with the water coming out of the hose at around 40 degrees, and the temps outside below 32, it doesn't take long for things to start freezing.  

[Brewman]

In our Optima owners manual, it says this is okay to do for very short periods of time (a couple seconds) to blow out any water in the plumbing.  

Question- If I were to do this (I have not had to yet), would the flow switch keep the heater off?  I'd be more worried about burning out the heater by running it dry than by damaging the pumps by running them dry for a couple seconds.  I'm guessing that running the pumps without water could cause them damage if done for a long enough time period- but that's just me guessing.

[SerjicalStrike]

The flow switch would keep the heater from coming on.  

[Perk1]

One thing that hasn't been mentioned:

Also: there is a tip which I think has finally made it into the owners manual about turning on the breakers. You need to turn on the 30 amp first, and wait for everything to settle. Run the jets for a few minutes, shut them off. Look at the surface of the water: when it is calm again, you should be able to see the water moving a bit directly above the floor fitting. This indicates that the small circ pump has caught its prime and is ready for you to power up the heater - that is - turn on the 20 amp breaker.

....

Hey Chas,  I was under the impression that I should turn on the 20 amp breaker first, prime the pumps,than turn on the 30 amp but you list it the complete opposite.  Have I been doing it wrong?

EDIT - I just downloaded the 05 manual. It seems they have switched the configuration so the 30 amp breaker now controls the jet pumps and circuit board.  I am pretty sure in my 02 Landmark the 20 amp breaker controls these functions.