Is my heater working correctly?

[Jd21476]

I have a new pool and attached spa that was built about 18 months ago. I paid for all the best equipment or at least I thought I did.

I have an 8’ round spa with about a 3.5’ depth. I have a Pentair Ultratemp ETi Hybrid Heater and a Pentair Intelliflo VSF pump. It takes about 3.5 hours to heat the pool from 56 degrees to about 95 degrees.

Is this correct or sound about right? My neighbor tells me no. He says he has a similar size spa and can have it up to temp in 40 minutes with a gas heater only.

Here are pictures of my setup. The valve circled in Red only seems to rotate about 10 degrees when I turn on the the spa. So with the pool on it sits in the position shown in the picture. When I turn on the spa it rotates so it is straight across.

 

[ajw22]

Show me pics of the red circled valve, which is your POOL/SPA RETURN valve when in both POOL mode and SPA mode.

What automation do you have? EasyTouch or IntelliCenter?

 

[1poolman1]

It appears that the return valve is set incorrectly. If that is "pool" position, most of the flow looks like it is returning to the (raised?) spa. The handle should be in the 1:00 o'clock position, not 10:00 o'clock, to send most of the water back to the pool.
According to Pentair's numbers, your spa should heat about 30 degrees in about 40 minutes. Does the spa continue to overflow a bit while running? That would indicate the suction valve is not shutting the pool off completely and it will take much longer to heat the spa that way.

 

[JamesW]

Are you running in "Dual" mode?

The gas provides 110,000 btu/hr at 93% efficiency, which is 102,300 btu/hr.

The performance of the heat pump depends on the air temp. relative humidity and the water inlet temp.

If we use their example of a 500 gallon tub using Dual mode and getting 193,000 btu/hr, it will take 39 minutes to heat up.

*Assumes a 500-gallon spa with a starting water temperature of 74^oF, air temperature of 70^oF and an ending water temperature of 104^o F.

UltraTemp ETi Hybrid Pool Heater operated in Dual Mode at 193,000 BTU output.

93% thermal efficiency gas engine coupled with high performance heat pump

In “Dual” mode the heater runs both the heat pump and gas heater simultaneously for maximum heat output

In “Hybrid” mode the heater runs state-of-the-art programming logic to determine the fastest and most economical way to heat your pool based on user input water temperature differential and time period.

https://orangecountypools.com/wp-content/uploads/2020/09/UltraTempETiHybridHeater.pdf

sku-page

Click here to find out where to buy the Quad DE Cartridges from Pentair, both online and locally.

www.pentair.com

https://www.pentair.com/content/dam/extranet/nam/pentair-pool/residential/heaters/ultratemp-eti/manual/ultratemp-eti-heater-manual.pdf

 

[JamesW]

500 gallons is 4,170 lbs.

193,000 btu/hr will increase the temperature by 46 degrees per hour or 0.77 degrees per minute.

So, a 30 degree rise from 74 to 104 will take will take 39 minutes.

I have an 8’ round spa with about a 3.5’ depth.

1,300 gallons is 10,842 lbs.

193,000 btu/hr will increase the temperature by 17.8 degrees per hour or 0.2967 degrees per minute.

It takes about 3.5 hours to heat the pool from 56 degrees to about 95 degrees.

39 degrees should take about 131 minutes or 2.19 hours.

 

[Jimrahbe]

JD,

I agree with poolman that your Return valve is not set correctly for the Pool mode.

That said, it sounds like the valve is moving to the right position in the Spa mode. So, the valve is not causing your heating issue.

I think you have some type of configuration issue with your heater. That is where I'd be looking for the problem.

Thanks,

Jim R.

 

[JamesW]

If we assume a heater output to the water at 180,000 btu/hr based on an air temperature of about 60 degrees Fahrenheit, the temperature rise should be about 16.6 degrees per hour. in "Dual" mode.

To gain 39 degrees, it would take 2.35 hours, not accounting for losses.

If the tub is uncovered, then it will also lose heat quickly and the heating time will be longer.

Even if the tub is covered, it will lose heat and the heat loss increases as the water temperature increases.

You should watch the temperature and note the temperature each half hour to see what the temperature rise is.

 

[JamesW]

39 degrees in 210 minutes is 0.1857 degrees per minute or 11.14 degrees Fahrenheit per hour.

That's a heat input of 120,811 btu/hr.

The gas heater can do about 102,300.

So, that would suggest that the heat pump part is only doing about 18,511 btu/hr.

Maybe you are not in Dual mode or maybe you are losing a lot of heat or maybe the valves are mixing cold pool water into the spa.

 

[Jd21476]

I appreciate all the help guys. I'm not too sure on all of this. I have the EasyTouch and unfortunately my pool guy has not been much help after the install. I dont really know the routing of the pipes under the ground and Im not sure what is supposed to be running to where.

 

[ajw22]

I appreciate all the help guys. I'm not too sure on all of this. I have the EasyTouch and unfortunately my pool guy has not been much help after the install. I dont really know the routing of the pipes under the ground and Im not sure what is supposed to be running to where.

Show me pics of the red circled valve, which is your POOL/SPA RETURN valve when in both POOL mode and SPA mode.

 

[JamesW]

Is the spa covered or uncovered when heating?

What is the air temp and humidity when heating?

Is the heater in "Dual" mode when heating?

The valve settings look to be off and you need to verify that they are correctly set and cammed to start and stop at the full turn rate.

Do you know the actual volume of the spa?

Does the spa have benches that take up a lot of volume?

 

[Jd21476]

I had a company come check it all out and they said it works fine. I guess the Pentair Ultratemp ETi Hybrid Heater is an ok heater but not the best. They said it is a heat pump and not a heater so the gas portion of it is only 110k btu where as a gas heater would be a 400k btu therefore it should take about 3-4 hours to heat up a spa of our size.

 

[JamesW]

heat up a spa of our size.

What is the size in gallons?

 

[JamesW]

39 degrees in 210 minutes is 0.1857 degrees per minute or 11.14 degrees Fahrenheit per hour.

That's a heat input of 120,811 btu/hr.

The gas heater can do about 102,300 (110,000 btu/hr x 93% efficiency).

So, that would suggest that the heat pump part is only doing about 18,511 btu/hr.

To me, it seems like it is underperforming.

The heat pump part should be able to do at least 70,000 btu/hr.

So, the total in Dual mode should be at least 172,300 btu/hr.

Assuming a 1,000 gallon tub (8,321 lbs), you should gain about 20.7 degrees per hour or about 0.34511 degrees per minute.

To gain 40 degrees should take about 2 hours.

 

[Variant]

OP, did you mean to say it takes 3.5 hours to heat up your spa or your pool? Your first post says pool, and that heating time sounds more reasonable. Based on subsequent discussion I'm guessing you meant spa.