in ground spa won't heat up

[wkrussell]

Split by moderator from HERE. Please start your own thread with your own questions. Thanks, jblizzle.

I'm going through this now. I have a 400 gallon in ground hot tub. I configured my hot tub so that is can run with the pool or by itself. I bought a 5.5 kw spa-pak from rheem. According to mfg specs the hot tub should heat up 5 degrees every hour. Starting off my hot tub is at 70 degrees. The first two hours the hot tub increases 5 degrees an hour as stated in the mfg specs. From there it tapers off. The third hour it increases 2 degrees, the 4th hour another 2 degrees. The next 6 hours it only increased to 2 hours.

1st hour 70 - 75
2nd hour 75-80
3rd hour 80 - 82
4th hour 82-84
The temperature only went up to 2 degrees over the next 6 hours to 86. A couple of factors I want to mention.

1. The heater is located near the pump which is about 15 feet from the hot tub.
2. Outside temperature in south Louisiana at the time was 74 degrees
3. I do not have a cover
4. It is an in-ground hot tub with over flow. However, I'm able to isolate the pump to just the spa when I run the heater.

I'm currently testing with a makeshift cover and will post the results.

I'm thinking that the distance from the heater to the hot tub is reason for most of heat loss but I'm still in the investigating mode.

 

[wkrussell]

Re: in ground spa - heater question

Update to my previous question. The makeshift cover increased the temperature but it still takes a long time to heat up.

 

[jblizzle]

Re: in ground spa - heater question

Seems odd. Just to be sure, you do have full suction and return only in the spa right? Nothing mixing with the cooler pool water?

 

[wkrussell]

Re: in ground spa - heater question

I do have full suction. However, I believe my deep end skimmer is introducing cooler water from the pool to the hot tub. I believe this is happening because the skimmer's valve keeps turning when I'm trying to turn it off. In other words I can continue to turn it towards the off position without it tightening. Also, water is overflowing from the spa to the pool at a very slow rate. This is a pretty good indication that I'm not only pulling water from the hot tub but also from the pool. I'm going to replace the valves this week. In addition I'm going to order a cover. I feel pretty good that this will fix my problem.

I'll keep you informed.

Thanks.

 

[jblizzle]

If water is spilling over, then you are certainly still pulling in cold pool water and that is your problem. What kind of valves do you have? The pool valves (like Neverlube) are much better than the cheap PVC ball valves which can fail.