Why is my heat pump not producing cooler water on chiller mode?

[anthonypool89]

I have a Jandy heat pump. I’ve never really experimented all that much with the chiller mode but given that today the water is 89° I thought I would try to temper it down a little bit.

So I turned it to chiller mode and the water coming out of the return lines is just as warm as if I set the heat pump on heat mode. I tried it both ways just as an experiment and even though the temperature set on chiller mode is lower than the existing water temperature, when the unit is set on chiller mode the water coming out of the return lines feels exactly the same as if I jack the temperature up above 90 and run on heat mode.

The other thing I’m wondering about is the direction and airflow of the fan seems to be exactly the same as when the heater is engaged. I’m not the most knowledgeable HVAC guy around but shouldn’t the fan be running in reverse and cooler water be coming from the returns?

I seem to remember trying this once before and the same thing happened along with the entire unit just not smelling right.

My Jandy is an Ae-Ti model. Do I just need to run it longer? Thanks for any ideas. 89° is starting to feel a little bit like taking a bath or a shower!

 

[mas985]

When switching modes in a heat pump, the evaporator and condenser just swap functions (refrigerant flows in opposite directions) and the fans do not change their flow direction. However, the water should be cooler by at least some small amount.

Did you use a thermometer to check the temperature?

What is the BTU rating for the heat pump?

What kind of pump do you have?

When in heating mode, can you tell the water is warmer?

Small BTU HP can have a small temp rise when flow rate is high so you may not be able to tell.

 

[anthonypool89]

Did you use a thermometer to check the temperature?

What is the BTU rating for the heat pump?

What kind of pump do you have?

When in heating mode, can you tell the water is warmer?

Small BTU HP can have a small temp rise when flow rate is high so you may not be able to tell.

mas....did not put a thermometer in front of the return lines. I only ran it a few minutes. BTU = 121,000 Jandy AE3000T-R Installed in 4/08. Pump = Hayward Super Pump #SP2607X10 rated at 85 gpm. Installed 7/09 but just replaced the motor last year.

In heat mode, it definitely works. Water feels warmer coming from the returns and it does warm the pool.

Thanks for the info. So then the fan is probably ok. What seems weird is that the water coming into the pool is just as warm when on chill as on heat. It shouldn't take more than a few minutes to feel differently, I'd think anyway (?)...referring to just the water coming into the pool, not the entire pool. I've always been disappointed that it doesn't work real fast. My friend has a propane heater and said it warms the water about 3 degrees an hour. Once the weather gets cooler, it's really a losing battle for the heater to keep up - it surely helps - but can run all day and only get the water up a degree or so. If it's a cloudy, rainy day, etc. no point running it at all. For the 13 years I've had it, I'd give it no more than a 6 on a scale of 1-10 (with 10 being totally satisfied with the overall effectivenss of it). These things have probably improved alot in 13 years, or not?

 

[Newdude]

These things have probably improved alot in 13 years, or not?

They don't work so great for the upper half of the country in cooler weather. The further north you go, the sooner they quit. Or those places with no humidity. Right now by you ? That bad boy will SMOKE the water. Really a moot point though.

 

[mas985]

That unit should change the temperature about 1 deg F per hour in ideal conditions. If the air is really hot, cooling could be reduced quite a bit.

Also at 85 gpm, the inlet to outlet temps would be a little less tha 3 deg F which can be hard to tell.

Has the unit be serviced recently?

 

[Newdude]

If the air is really hot, cooling could be reduced quite a bit.

I was wondering if it was a similar effect like turning the heat pump on with 60 degree water on a cool day. Can't even tell its working. Is it the same thing? Does it chill already cool water really well like the heat pump shines in warming already warm water ? And leave alot to be desired all other times ?

 

[mas985]

The COP of HP is related to the difference in temperature between the air and the water. In heat mode, as the air temperature drops below the water temperature, COP starts to drop and BTU transfer drops. In cooling mode, it is the opposite effect, as the air temperatures rise above the water temperatures, COP drops and BTU transfer drops. Either way, when the spread gets too large in the wrong direction, no more heat can transferred. Sometimes manufactures will publish charts that show these changes.

 

[anthonypool89]

Thanks for all of the above info. All I know is that I tried it again this evening and, on chill, it was putting out REALLY warm water. I'd actually say that it was heating the pool...on chill setting....way better than it does when the water is cooler and the thing is set on heat. Wires crossed...whatever. I'll see if the pool store responds, cause there's not a thing I can do with it.

 

[anthonypool89]

I was wondering if it was a similar effect like turning the heat pump on with 60 degree water on a cool day. Can't even tell its working.

I don't think so. Everytime I've ever used it - I can always feel a significant difference in the temp of the water coming through the return lines, i.e. warmer, than the rest of the pool. But, what was coming through the lines tonight - while on chill - was WAY warmer than anything I've ever felt when on the heat setting. Let's face it, the thing is just plain confused

 

[anthonypool89]

Has the unit be serviced recently?

Near the end of the 2019 season - it quit working. Fan wouldn't run. Pool store replaced a bad capacitor (I think....one of those small parts in there on the board). Other than that, nothing has ever been done to it. Knowing the store that installed it, they probably screwed it up from the very beginning. Maybe should have been running it on chill setting on these years - might have heated the pool faster. Oh well, it's always something....

 

[AK-]

For how long did you have it in cooling mode before checking the return temp?

I also turned my to cooling Today. I only got warm water for the first 10-15 and only after that the return temp was slowly getting noticeable cool.

 

[revitup]

When on chill mode the fan exhaust air will be warm, it’ll feel cool on heat mode.

 

[anthonypool89]

I only got warm water for the first 10-15 and only after that the return temp was slowly getting noticeable cool.

Well, I suspect I didn't run it more than 15 minutes, so maybe should give it another (longer) try.

When on chill mode the fan exhaust air will be warm, it’ll feel cool on heat mode.

In that case, it's definitely not working since the exhaust air above the fan is cold while on chill mode. Thanks so much for mentioning this - that pretty much confirms a problem. I was thinking that it should be throwing out heat, not cold. Beginning to wonder if this thing has ever really worked the way it was supposed to, even from new.

 

[AK-]

Mine also takes some time to exhaust warm air in cooling mode.... I'd probably be wondering if it works too... luckily (or not) I accidentally put my pool to cool when my water needed heat when messing with the controllers, so I knew cooling worked.

 

[anthonypool89]

AK....well, guess I can crank it up and leave it on for more like an hour or so - can't hurt (other than making the water even warmer!) That shallow end of the pool REALLY felt like a hot tub while that thing was running!!

 

[AK-]

AK....well, guess I can crank it up and leave it on for more like an hour or so - can't hurt (other than making the water even warmer!) That shallow end of the pool REALLY felt like a hot tub while that thing was running!!

I hear you. I have no deep end… at 92.6F my son was saying the pool was an oversized bathtub.

 

[Newdude]

Test the theory that it needs time to do its thing and leave it on overnight. In the morning you should be able to feel the difference at the returns.

 

[anthonypool89]

t 92.6F my son was saying the pool was an oversized bathtub.

LOL....seriously!! I get too bogged down when trying to do laps when the water is this warm. Ideal for me is maybe 82 at the most. Otherwise, it doesn't really feel "refreshing". Well, the pool IS essentially a big bathtub!! He's right.

 

[revitup]

Just as a point of reference, when our HP switches to cool mode the return water immediately (certainly within minutes) feels cooler. I’ve measured a 3 to 5 degree difference at the returns.

 

[Leebo]

I’d also be slightly interested in seeing it run longer than a few minutes. We’ve seen rather abnormal temps the last week or so and I wonder if it’ll just take a second. Even at 8pm last night it was still hovering around 90° here and I suspect your temps are close. As you mentioned, can’t hurt anything.