Anyone using a tankless water heater to heat a pool or spa?
- Thread starter Subdave735
- Start date
I am actually contemplating doing the same thing. I am putting my equipment in my side hard which is only 5 feet from the house to the wall around my property. I picked up a brand new $1200 rheem 200k btu heater for $350. I don't really need it as our house is only 2 years old, but I figured it was a good enough deal that I would buy it. Then I got to thinking about how much room it would free up if I could use it for the pool instead of the house. I considered that it might be a bottleneck, so my solution would be to buy two heaters and not have to worry about the bottleneck. The heater would be on my variable speed pump so I could control flow as much as I need to. The rheem tankless heaters come with a remote as well so it would be easy to control without having to dig around the equipment every time. I might try it out, do some more research first though. But really, a pool heater is just a tankless water heater. I just need to look at how they are both built and what materials are used, see what all the differences are between the two. For a lot of people it wouldn't make sense, but I can get these cheap enough that I can buy 6 of them before I catch up to what my Jandy LXI will cost.
Good luck. You'll probably burn the unit out. These whole house tankless heaters are not made for the type of flow a pump puts out nor for the amount of time they run. These units are design for small bursts per say and not constantly on. Also consider the chemicals in the pool water vs household water.
This is like asking "Can I put a space heater in my HVAC ductwork and heat my house?"
checking to see if u did try with the tankless water heater and how it worked out - was thinking of doing same -
Esloser
0
Re: Anyone using a tankless water heater to heat a pool or s
Curious how much you spend a month heating the spa and how much you use it? I'm also having a spa installed that is 7x7 with 6 jets and a 400k btu heater. I was estimating $10 per day to operate 5-6 hours, but was pulling that number from my behind.
Curious how much you spend a month heating the spa and how much you use it? I'm also having a spa installed that is 7x7 with 6 jets and a 400k btu heater. I was estimating $10 per day to operate 5-6 hours, but was pulling that number from my behind.
Re: Anyone using a tankless water heater to heat a pool or s
To get an accurate idea of cost to run the heater, get your last gas bill out and look at the number of therms you used and the total bill cost. Simple math will get you the cost per therm. Your 400,000 BTU heater uses 4 therms per hour.
To get an accurate idea of cost to run the heater, get your last gas bill out and look at the number of therms you used and the total bill cost. Simple math will get you the cost per therm. Your 400,000 BTU heater uses 4 therms per hour.
Esloser
0
Re: Anyone using a tankless water heater to heat a pool or s
ok - so it looks like it will cost $4.60 to run per hour. Do you get any efficiency by running it longer. I'm guessing you will use constant energy while heating the water for the first 30 minutes, but then it will go into a maintain where the temperature is dropping a couple of degrees from the spa to the heater.
ok - so it looks like it will cost $4.60 to run per hour. Do you get any efficiency by running it longer. I'm guessing you will use constant energy while heating the water for the first 30 minutes, but then it will go into a maintain where the temperature is dropping a couple of degrees from the spa to the heater.
The output on these house tankless water heaters isn't enough to heat a large body of water. Plus the heat exchanger's aren't large enough to allow proper flow. Remember, these units are designed for low flow.
I will give a try on my own pool, down to SoCal area, we've been thinking the same idea for pool heating since we are limited from changing gasline pipe size. if it does not work for the pool( 22,000Galon) I would just use it to upgrade my residence old tank heater.
I would just run the hot water straight to my pool from the heater, so it doesn't cause any trouble to the pump flow rate. if water level gets to high, I will just use backwash to discharge some water,( also do my backwash), it doesn't cause that much money now days for the tankless heater, so it will be interesting to see, if it's working or not. I will keep you guys posted.
I would just run the hot water straight to my pool from the heater, so it doesn't cause any trouble to the pump flow rate. if water level gets to high, I will just use backwash to discharge some water,( also do my backwash), it doesn't cause that much money now days for the tankless heater, so it will be interesting to see, if it's working or not. I will keep you guys posted.
Are you saying you are not going to run pool water through the heater? And just going to run fresh water through the heater into the pool. This is not going to work very well for a variety of reasons.
- May 23, 2015
- 24,485
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
If you can’t change pipe size, then can you run at higher gas pressure? One way to deal with a smaller diameter pipe is to have higher pressure gas (2-3psi) fed from the meter to the equipment pad and the another regulator at the pool heater to take the high pressure gas down to the 7-10 WC needed to feed the heater. It costs money to do because you need a licensed gas plumber to set it up right but it should be doable unless the gas company or local regulations forbid it...
blakeusa
In The Industry
It would be plumbed just like a normal heat exchanger if you were using an external furnace.
pool heat exchanger to tankless hot water diagram - Google Search
pool heat exchanger to tankless hot water diagram - Google Search
Matt has a very good idea here, check it out most utilities localities go this way now.
If you go with a tankless water heater to heat your pool you may be sorely dissappointed as most hot water heaters run from 40 -60,000 BTU, pool boilers for 20k pools run from 100-400,000BTU. I know my heat exchanger on my hot water tank will help with over night heat loss but not much more.
Yes tankless water heater using propane a great way to heat your spa.
I am using a surflow 2gpm rv pump that requires 5amps of power. It is connected to a 6amp laptop charger. I am then using a propane 2gpm tankless water heater. The hoses i am using are 1/2 inch od. I am able to heat my 220 gallon hot tube using a tankless water heater to 104°F within 2-3hours.
All of this, tankless water heater, hoses, laptop charger, surflow pump, clamps, propane hideaway, propane tank only costed me approx $150!!
This setup is still running true coming onto 14months and have refilled the propane tank three times!
It works great and i use my hottube everyday.
Tankless water heaters combined with propane is definitely a great way to heat your spa espcially if it will cost hundreds if not thousands to replace an actual pool/spa heater.
I am using a surflow 2gpm rv pump that requires 5amps of power. It is connected to a 6amp laptop charger. I am then using a propane 2gpm tankless water heater. The hoses i am using are 1/2 inch od. I am able to heat my 220 gallon hot tube using a tankless water heater to 104°F within 2-3hours.
All of this, tankless water heater, hoses, laptop charger, surflow pump, clamps, propane hideaway, propane tank only costed me approx $150!!
This setup is still running true coming onto 14months and have refilled the propane tank three times!
It works great and i use my hottube everyday.
Tankless water heaters combined with propane is definitely a great way to heat your spa espcially if it will cost hundreds if not thousands to replace an actual pool/spa heater.
I’m going to hook up tankless water heater to my “smaller” 11000 gallon pool, I’ll update how it goes in a couple months.