Insane Question

[mickey4paws]

Kinda like floating in bathwater. It's very nice for night swimming.

On a hot day it's def too warm and not refreshing at all...86 is better on a hot day. I tend not to get in if it's less than 84 and only then if I HAVE to. I got in on a hot day at 78 and that was cause I HAD to vacume. It wasn't awful, but not for me.

I haven't been swimming at night in a while, but that is a good point and does sound nice. I think I've probably convinced myself that 82 is warm enough for me because our heater died (have a brand new Lochinvar heater in the garage just waiting to be installed). We've been having an unusually cool summer here. I like when it's in the 70's outside and the pool is in the low 80's. I think that's easier to jump into than if it's really hot outside and cooler in the pool. But 93 pool water temp still sounds really warm!

 

[mitch08]

I have a thought. The heaters has an internal overheat shutdown. Normally that won't get triggered till the output water reaches around 120. If the flow rate is enough lower in pool mode than it is in spa mode, the water will get hotter in the heater in pool mode than it does when in spa mode. That could be enough to trigger the overheat sensor, especially if it is triggering early.

One quick way to check into this possibility is to look at the filter pressure in pool mode and in spa mode. If the pressure is higher in pool mode, this is worth investigating. This could also happen if pool mode runs the pump on a lower speed than spa mode does.

After a little more investigation, I think you are 100% right about this being a flow rate issue. Now the only question is, what can I do about it? Should I just take Launboy's advice and tell her it won't work? Or is there a simple way to correct this?

I backwashed the filter and that seemed to help by about a degree (or it is in my head)...

I do have a 2 speed pump but I almost never run on low speed. My heater doesn't run at all when the pump is on low speed. Im not sure if it should. Thanks!!!

 

[sbagdon]

Going from pool mode to spa mode is pretty typical of spill over spa setups. A couple of levers that controls the water flow. When I am in spa mode, the suction and return comes only from the spa. When in pool mode the suction and return comes only from the pool. When its spilling over the suction comes from the pool and returns through the spa. Pretty basic. the heater has no idea which is which. It is purely controlled by the settings on the thermostat.

Changing the water inputs will most probably change the water conditions (pressure, air quantity, etc). When you add the pool to the input, do you see air in the pump basket?

If the heater is turning off, it's turning off for a reason. Any way you can figure out that reason? Water pressure, gas pressure, overheat, timer, etc?

 

[mitch08]

Going from pool mode to spa mode is pretty typical of spill over spa setups. A couple of levers that controls the water flow. When I am in spa mode, the suction and return comes only from the spa. When in pool mode the suction and return comes only from the pool. When its spilling over the suction comes from the pool and returns through the spa. Pretty basic. the heater has no idea which is which. It is purely controlled by the settings on the thermostat.

Changing the water inputs will most probably change the water conditions (pressure, air quantity, etc). When you add the pool to the input, do you see air in the pump basket?

If the heater is turning off, it's turning off for a reason. Any way you can figure out that reason? Water pressure, gas pressure, overheat, timer, etc?

Thanks.

I don't think there is any difference if I just change the return. I think any pressure changes or water flow changes would be when I change the suction. If I have the spa spilling over or I have the pool fully in pool mode, the heater still cuts off.

It is only when I switch the suction to the spa that the pressure changes a bit and the heater runs to 104 with no issues.

There is absolutely no air at all in the gasket and the pressure difference is 1 point at most. It goes from 23 to 24 when I put it into full spa mode.

It is very difficult for me to tell why the heater is cutting in and out because it is a very old heater and there are no diagnostics.

Thanks for your help.

 

[mitch08]

So I have an update in case for some crazy reason anyone here is interested. :lol:

After my backwash test, I was able to heat the pool to 95 degrees with no problems at all

So it must have definitely been a water flow issue.

It is still strange to me how the spa is not affected by any water flow issues, and only the pool is, but I won't harp on it too much. It seems that as soon as my pressure crawls up a few points, the heater wont push past 92 degrees. But if I backwash and bring the pressure back down a few points, it works fine.

Now the bigger problem I have is convincing my wife she is nuts.
BTW, she complained that the 95 degree water was way too hot and uncomfortable last night. ROFL!!! So it needs to be exactly 93 for her at night. I can't win!!!

 

[Bama Rambler]

So it needs to be exactly 93 for her at night. I can't win!!!

And you expected to??? You know there's no winning. You're doing good to maintain.