Heater pressure problem, won't start, air in pump + returns

[anonapersona]

It appear that the heater will not come on due to pressure.

Booklet says either a filter problem or line blocked or something like that. I seem to recall that last winter just cleaning the filter made all the difference. I could clean what I have and see, but it is cold outside and I am under the weather (something I ate??). When the spa is on, there are a LOT of bubbles in the filter and the returns to the spa, but bubbles are not on. Seems like cavitation.

I am thinking, clean the filter or just buy new carts. (did I mention I feel crummy?). Am I being stupid and lazy? Is there something actually wrong with the heater?

 

[Bama Rambler]

If your cartridges are clogged and restricting flow enough it would reduce the pressure enough to give the heater a problem. However, it shouldn't introduce air into the system. Sounds like a suction leak too.

 

[anonapersona]

The air issue has come and gone before. It's been so long since we've run the spa that I've forgotten the details of how that stopped the last time. But that it did stop seems important.

And when the heater WAS repaired, they installed a new temperature probe. The old part was missing that long extension. If that extension broke off might it be lodged inside the heater and creating the pressure problems when combined with the filter?

I do note that the running pressure on the filter is now about 18 psi when running the pool vs 16 psi clean pressure (I have no idea what new pressure may have been) and when switched over to the spa it jumps to 23 psi which is above where we normally would clean the carts.

We do have some minor leaks at the pumps, I will look to see if any are more significant than before.

Anyhow, I've ordered new carts online, selecting the Pleatco over Unicel after shopping both websites. Also the Pentair Clean & Clear Plus website states that cartridges should be changed out every 3 years. I've had these for 2 years and they were far from new when we bought the house so new carts seems wise at this point. That will give us the ability to do a long soak and cleaning as we alternate carts in the future. By the time they arrive the weather will be warmer and I should feel better too.

If the new carts do not fix the pressure problem and the air problem then we have some investigation to do before calling a repairman. I was rather unhappy to see what the temp probe repair cost vs the cost of the part itself. I don't mind a hefty cost/hour for repairs but $270 to switch out a temp probe was too much. I watched, it was simple to do. I get that knowing what to repair is key but that is part of the hourly rate IMO.

 

[anonapersona]

Followup... Everything is fine now. I don't really know why. Changed out the carts, heater would come on but not get up to 101, still lots of air in the returns. Cleaned out the filter basket, then it was better, less air bubbles but still not getting up to temp. Cleaned basket again, a few leaves found their way back in. Air bubbles in spa returns stopped, still some bubbles in filter basket but less. Found that the heat selector knob was just a touch less than max heat. Finally, everything seems OK and stable, got up to 101 as expected.

So, maybe it was just so much air in the return lines from not running the spa for so long that the air pockets created an obstruction to flow when combined with the old carts and some normal junk in the filter basket. I dunno. I think my lesson here will be to run the spa without heat for many hours to see if the air in the lines eventually goes away. And doing that before I try to add the heater into the mix. And being sure the heat selection knob is at max, not a scant 1/8" before that.

[edit] A Search of the Forum showed a post "Air in filter basket while is spa mode" or something like that which suggests that I need to lube the O-ring of the pump basket. Perhaps the increased suction in spa mode is letting a bit of air get past the o ring. I'll do that next and see if that knocks out the last bit of bubbles I am seeing.