Spa Heater Problems

	AquaCal is America's Leading Producer of pool and spa heat pumps, for residential, commercial and resort applications.  In most areas, heat pumps are a more cost-efficient, cleaner and quieter alternative to fossil-fuels heaters.  Click any image, for Complete Product or Ordering information.

How to solve spa heating problems and protect the heater from corrosion? Spas and hot tubs require routine care and periodic maintenance, in order to preserve and maintain the good operating condition of the heater and other equipment. Manufacturers' trouble-shooting guides should be consulted for maintenance or replacement instructions. Heater corrosion can result from poor management of the spa water chemistry and chemical additions and should be completely avoidable. If problems arise, refer to the Spa Problems Page, as a source of problem-solving information, broken down into various categories.  Scroll down the page and click on the linked keywords, catch phrases or images, in the archived answers below, to access additional information, on that topic or product.

Join our E-Letter Mailing List.   You'll receive 1-3 E-Letters a month, featuring helpful pool and spa advice, new product information and sale announcements.  All we require is your e-mail address and you can opt out anytime you wish.  Your information will never be shared or sold.

► Too Hot To Handle?

Our hot tub temperature has really gotten hot. When we turn it back, nothing happens. Temperature remains hot. I'm trying to avoid the expense of calling a professional that lives far away. Any suggestions or help would be appreciated. Thanks.

Gloria N., 5/13/2011

Your spa needs to be serviced and I am not knowledgeable enough to be of assistance. Spas are equipped with high temperature shut off switches and thermostats. It seems that something has failed. High temperatures, above 104ºF or 40ºC, can be dangerous to the bathers and should be avoided. If you want the use of the spa, I don't see how you have a real choice. Sorry that I couldn't be of more help.

Sincerely. Alan Schuster, 5/13/2011


► Economics Of Shutting On And Off?

Is there a study which compares cost of maintaining a constant higher temp verses turning spa down between use to a lower temp then bringing back to temp each time the spa is used. I can find cost of operating spas but no study on turning up and down vs. constant temp. Logic tells me it would be cheaper to maintain a constant temp, but I have some spa owners who insist that we turn spas down between use to save money. Thanks for your help, and I appreciate your advice.

Tim J., 4/18/2012

This gets asked a few times a year. I know of no study on this subject. Analyzing the physics behind the question tells you the heat loss to the environment is less, as the water temperature drops closer to the ambient. Much depends on how well the spa is insulated and the type and fit of the cover. Yes, I think you can save money. But, it could be pennies and you will lose the ability to enjoy the spa whenever the mood strikes. If there is money to be saved, this is not a really an effective way. Maintaining good and consistent water quality and filtration will help minimize problems and that will really save on operating costs. An ozonator to destroy wastes and a Spa Frog Mineral Sanitizer for persistent backup sanitation are a great way to reduce chlorine or bromine usage, without sacrificing water quality. I hope this helps to put things in perspective.

Sincerely. Alan Schuster, 4/19/2012


► Economics?

We have a 1000 gallon spa in operation outdoors, at a spa resort. Currently, it is being heated by propane. Being that the spa is not covered, heat loss is considerable. Would a heat pump make sense, in terms of cost and temperature recovery time? Thanks.

Bret F., 12/4/2004

There is absolutely no doubt that an AquaCal heat pump will result in a considerable savings. Exactly how much will depend on the cost of propane and the cost of electricity. But, it will be more than enough to justify the switch. As a bonus, it operates a lot cleaner too. The size of your spa and the uncovered feature, makes a heat pump a viable alternative. Good luck and I hope that I have been helpful.

Sincerely. Alan Schuster, 12/5/2004


► Excessive Heating Costs?

I recently purchased a house that has an inground granite spa that sits completely in concrete. I ran the spa with temp. on 100°F for 30 days and my utility bill went up $300.00. Original owners say they also had this problem. My electrician says it is the electric heat and my pool man says it still shouldn't be that high but doesn't seem to know what to do to make it efficient. I have had a large above ground spa before and ran it 24/7 and never even noticed that it even used electricity. Spa runs on 220. totally electric, was digital but wasn't running, so pool man changed to manual on and off. Electrician questions spa heating element. Pool man doesn't seem to know. Note: Original home owners say the pool company that installed the spa have tried to correct the problem but had no success, so they stopped using it. Please help. Any possible answers to problem will be greatly appreciated.

JBF, 5/14/2005

The cost of heating electrically is based on power consumption. Better reduction of evaporation and heat loss will reduce electrical consumption and costs. Is this spa covered when not in use? Otherwise, the heat loss will be considerable. Not only will the heat radiant away, but even more will be lost through evaporation. Covering can be a bother, but is will produce big savings. Want covering at the press of a button? An automatic safety cover might be just what you need. Electric resistance heaters are not very efficient. and this plays a direct role in your heating costs. You might consider having an AquaCal heat pump installed, as this type of heating is, perhaps, the most cost effective means. I hope that this will help find a solution.

Sincerely. Alan Schuster, 5/14/2005


► Heater Corrosion?

Recently, I had a corrosion problem with my spa heater. What can I do to avoid a repeat?

Brady, 11/4/2007

Copper/copper alloy heater components can be adversely affected by low pH, in the presence of chlorine or bromine. The best way to avoid low pH levels is to maintain a total alkalinity of 80-120 PPM. Some products such as trichlor tablets should not be used in a spa. In addition, bromine tablets are best utilized in a feeder or floating dispenser. Electric heater and heat pumps, that utilize a titanium heat exchanger, are far more resistant to corrosion. Frequent testing of the spa water is always a good practice. I hope that I have provided some helpful information.

Sincerely. Alan Schuster, 11/5/2007


► Turned Blue?

Admittedly, I neglected the spa for about a two week period. Upon realizing it was not checked for some time, I checked, and found both chlorine and pH low. I attempted to raise the pH first, with sodium carbonate, I believe. I have some pH plus that I never had a problem with and while adding it a little at a time, the water turned blue. I raised it to 7.0, shocked the water and cleaned the filters. I then set the automatic filter cycle to run continuously, to filter out the blue color that precipitated out of the water. It has been running for 6 hours now, and is as blue as the Caribbean. Short of draining, washing, and refilling the tub, can you offer any advice or assistance? And any advice to prevent a recurrence? Thanks!

Joe, 10/8/2006

There seems little doubt that this is a copper problem. The low pH caused copper corrosion to occur in the heater. I would advise draining and cleaning the spa. Spas should be drained occasionally and this is a good time to do it. I would add a dose or two of a quality metal chelating agent, such as Liquid METALTRAP, after the spa is refilled. You mentioned chlorine - I hope that it was not trichlor tablets, as it could be part of the problem - too acidic. Dichlor is what is used most often. Hopefully, the damage to the heater was not serious, but each instance of low pH will take its toll.  I hope that I have been helpful.

Sincerely. Alan Schuster, 10/9/2006


► No Heat?

Dear Alan, I heard you were the man to ask about spa trouble. I have a 1996 Spa. It will not heat, it will cycle but no heat. I have had this trouble for a month now. I changed the pressure switch and nothing has changed. I don't know where the thermostat is so I can not check it. Please if you have any insight let me know.

Desperate, 12/30/2010

While I can usually offer advice on spa water chemistry, water quality and related maintenance issues, your question is very product specific. I can point you towards possible solutions, but it is the manufacturer that should be best able to offer trouble-shooting information. In most cases, if the power is interrupted, the thermostat may need to be reset. Check to see what temperature the spa is set to maintain. It may be set below the current water temperature and should be raised to the desired temperature. Look for a circuit beaker that may be protecting the heater and may have tripped. Most spas, if not all, are equipped with a high temperature cutoff switch, which prevents temperatures from rising above 104°F. This is done for safety reasons, as higher temperatures can be dangerous to the health of bathers.   Possibly there is a problem with this switch. Sorry that I can't offer more but I have no access to model by model information. I hope that this information will prove to be useful. If this website was helpful in providing information, please tell your friends and dealers about the website.

Sincerely. Alan Schuster, 12/30/2010


► The Best Temperature?

What is the best temperature for a hot tub? For some reason I am having a hard time finding the right temp to set it. No one seems to know.

Robert S., 2/15/2006

This is an entirely individual preference. A temperature of 104ºF is the safe maximum. With kids you might want to lower the maximum. Most people keep the temperature at 100 - 104ºF. In the summer months, many people keep it at a pool-like temperature. It's what makes you and the family comfortable. Enjoy the spa.

Sincerely. Alan Schuster, 2/15/2006


► Spa Cooler?

I have a 400 gallon above ground spa that gets up to 102°F degrees with the cover on! How can I lower the temp? I don’t like the temperature over 98°F. Is there a spa cooler of some sort? Thanks.

Bob D., Arizona, 7/27/2005

There is equipment used to cool swimming pools. It should be possible to do the same with a spa. AquaCal Heat Pumps offers a broad line or quality products, that heat water, chillers that cool water and units that do both. Hopefully, this information will help you cool off.

Sincerely. Alan Schuster, 7/28/2005


► Shutting Off?

Presently I have an outdoor spa and the heater isn't working. The spa is set up on a timer and when it comes on it is supposed to turn on the heater. The controls are equipped with a manual over ride and when I hit the button you can hear the motor attempt to run and then it turns itself off. Would my heater thermostat be bad or is my motor bad? How do I check either one of these? Thanks for the help.

Johnny G., 3/13/2004

There are several possibilities: thermostat problem, high temperature cut-off switch problem, pump problem, controller problem or a circuit breaker problem. I suggest that you prefer to a trouble-shooting guide or the spa manufacturer's website for additional insight, as this is really out of my field of expertise. Good luck and I hope that I have helped point you in the right direction. Good luck.

Sincerely. Alan Schuster, 3/14/2004


► Cooling Off?

I have a spa and the water gets real hot and then a week later it's only warm. I use it about once a week. Should there be a timer to set? Or is it run only from the cold to hot knob. Thanks for your time P.S. my cover is starting to come apart, Could hot air be seeping out to cause this problem?

Cold In California, 1/29/2008

Most likely you have a problem with the thermostat or the controlling devices. Most spas have a thermostat that can be set at a particular number. The temperature is controlled by the heating switching on according to the thermostat or a controller setting. You need to check to make sure that the settings are correct. It is also possible that a sudden power outage can alter the thermostat settings, dropping the setting to the lowest number. This will prevent the heater from coming on. Check to see what temperature the thermostat is actually set at. The display may only show the actual water temperature. With the variety of spas and equipment on the market, it is impossible for me to be more specific. You should refer to the trouble-shooting guide in the owner's manual or contact the manufacturer and/or dealer, if problems continue. The poor condition of the cover, is not the cause of the problem. It does, however, cause heat loss and should require the heater to be used more than necessary. I hope that I have been of help.

Sincerely. Alan Schuster, 1/29/2008

 
► Higher Spa Temperature?

We usually keep the spa water at 104ºF and use it for about 20 minutes at a time. I don't seem to be able raise the water temperature above this point. I would like to try a slightly higher temperature. Is there a reason this is happening?

Flagstaff, AZ, 12/12/2004

Temperatures above 104ºF can be dangerous. Most, if not all spas, are equipped with high temperature cutoff switches that prevent the temperature from rising above this point. Even at 104°F, bathing time should be limited to about 20 minutes, especially if fully immersed in the water. Special individual health requirements should be factored into the spa usage. I hope that I have been helpful.

Sincerely. Alan Schuster, 12/12/2004


► Intermittent Operation?

My husband and I use our spa every evening and sometimes in the morning, during the winter-time in upstate NY (i.e. cold weather). He usually turns the temperature up an hour or two before use and then turns it down, under the impression that this will save on heating costs. I think keeping it at a stable temperature is probably just as economical. Do you have any idea about this? Cheers.

S. D., New York, 10/22/2006

In theory, a warmer spa will lose more heat to the surroundings. Therefore, shutting off the heater could save money. How much? The savings, depending upon the insulation, might be trivial, in the overall scheme of things. Heating isn't 100% cost efficient, so it does cost more to replace lost heat. Considering how often the spa is used, why give up the ability to use the spa, anytime you want, for some pocket change? I hope that this information will be helpful.

Sincerely. Alan Schuster, 10/23/2006

▲ Return To Top Of Page ▲