Low PSI on low speed can't run heater and gurgling noise from one jet

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R

Rockstead

Well-known member
Sep 2, 2010
476
Montreal, QC, Canada
Pool Size
100000
Surface
Vinyl
Chlorine
Salt Water Generator
I recently made 2 changes, replaced 1.5HP pump with 2 speed Hayward and I also replaced my 5 pool jets with the slotted type instead of eye ball.

My PSI at high speed is about 15 and at low it is 3.

When the pump was first installed this season, it was able to turn on the heater and now it can't but I didn't record the original PSI.

The other problem that I haven't been able to solve and I don't know if they are related is that I can hear one of my jets in my pool stairs making noise, like maybe air is trapped and it doesn't change if I adjust the slotted jet.

No amount of back washing, rinsing, ricurculating is making a difference.


I'm also ready for a service call on both issues, hopefully I can get some advice here to fix it.
 
Hello,
Are you backwashing and heating on high?

Backwashing will need to be done on high speed. Heating is more efficient on high speed also.

On low speed, air bubbles will tend to clump together into larger bubbles, until they work themselves out.

Some Heat pumps have an adjustable flow/pressure switch, looking at the manual it appears yours does not.
 
bobodaclown said:
Hello,
Are you backwashing and heating on high?

Backwashing will need to be done on high speed. Heating is more efficient on high speed also.

On low speed, air bubbles will tend to clump together into larger bubbles, until they work themselves out.

Some Heat pumps have an adjustable flow/pressure switch, looking at the manual it appears yours does not.
Click to expand...


At this point I do everything on high due to the fact the heater stopped working on low and I thought the noise from the jet would work itself out but it's been over a month.

Is it normal 15 PSI for high and 3 PSI for low?
 
That could be the pressure switch. Low speed for most pumps is right on the edge of minimum flow rate for a heater so the heater pressure switch may be tripping. The reason it worked before is that the pressure must have been higher at that point and there could be several reasons why the pressure dropped since then:

Dirty filter
Partially clogged impeller
Partially clogged suction pipe
Different valve settings
 
mas985 said:
That could be the pressure switch. Low speed for most pumps is right on the edge of minimum flow rate for a heater so the heater pressure switch may be tripping. The reason it worked before is that the pressure must have been higher at that point and there could be several reasons why the pressure dropped since then:

Dirty filter
Partially clogged impeller
Partially clogged suction pipe
Different valve settings
Click to expand...

Would any of the above explain the air that is in one of the jets?

All my valves are open, except for the valve between the hold and cold valves connecting to heater, opening it doesn't make a difference, pool installer just told me to always keep it in that configuration when heater is running and reversed when not.

Are there any explicit instructions I can follow to verify and resolve if it is one of the 4 reasons above?
 
Note that you should never open the heater bypass valve all the way when the heater is on. I would suggest a flowmeter to monitor the flow going to the heater. I would also suggest adding an actual flow switch to replace the pressure switch.

What pump do you have?

Is the AquaLogic saying No Flow?

Is the AquaLogic configured for the two speed pump?

Does the salt system work on low speed?
 
Would any of the above explain the air that is in one of the jets?
Click to expand...
Yes. A suction blockage would explain that because it can create an air leak in the pump basket which it turn could pass air on to the filter and out the returns.

Try back flushing (from pump toward skimmer) the suction line to see if you can clear any of the debris.
 
JamesW said:
Note that you should never open the heater bypass valve all the way when the heater is on. I would suggest a flowmeter to monitor the flow going to the heater. I would also suggest adding an actual flow switch to replace the pressure switch.

What pump do you have?

Is the AquaLogic saying No Flow?

Is the AquaLogic configured for the two speed pump?

Does the salt system work on low speed?
Click to expand...

Pump is Hayward 1hp 2/speed

The AquaLogic doesn't say low flow, the heater says that when the pump runs low

I believe I have the AquaLogic set to 1 speed because I never had an electrician in to wire in both low and high to AquaLogic, so even when I set the AquaLogic to 2 speed, it makes no difference, it just runs at whatever speed I manually left the pump on last.

I believe the Salt System to be working in low because it doesn't give me an error message saying it isn't, I don't know if that is actually confirmation.
 

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mas985 said:
Yes. A suction blockage would explain that because it can create an air leak in the pump basket which it turn could pass air on to the filter and out the returns.

Try back flushing (from pump toward skimmer) the suction line to see if you can clear any of the debris.
Click to expand...

I will try it but not sure how, my normal backwash is leaving all valves open and just setting the multi valve to backwash, but when you say back flush I'm not sure you are referring to backwash or what valve configuration to go from pump to skimmer.
 
I think that a flowmeter could help you diagnose the issue. Pressure switches are not very good when used as flow detectors unless the system is within specific parameters. I would suggest adding an actual flow switch to replace the pressure switch.
 
Sorry James, but at this stage, I just don't see how spending time and money on a flow meter is going to help much. A typical Blue White flow meter is a pretty expensive piece of hardware and no more accurate than just estimating the flow rate from the filter pressure and plumbing layout. Personally, I think they are a waste of money.


Also, I don't think adding a flow switch to the heater is anymore "safe" than using a pressure switch. I understand where you are going with that but again, extra cost for not much extra safety. Most heaters have triple safety redundancy. The pressure switch, the thermal limiter switch and the pressure bypass valve. All three would have to fail at exactly the same time for there to be a catastrophic failure. But that could happen to a flow switch as well so I don't see the point.


Anyway this really doesn't solve the OPs issue so no reason to go on.
 
About $65. Not cheap, but I think a worthwhile investment in some cases, such as this. I'm sure that you could estimate the flow fairly accurately, but it's not so easy for most other people.

A pressure switch is not going to do well on a system with low back pressure. A flow switch is more reliable and can be an important safeguard against mistakes like accidentally leaving the bypass open.

I have seen several cases where the heater was damaged when the bypass was left open and the heater fired with insufficient flow because the pressure switch doesn't detect actual flow.

If a heater fires with very low flow, it can easily destroy the heat exchanger before the high limit kicks in.
Buying a new heater with installation is not cheap.

A flowmeter and 30 gpm flow switch could verify that the heat pump is getting the recommended minimum of 30 gpm
 
Not sure what to do here based on the responses and my two separate issues, 1. Heater not running when pump is on low anymore and 2. Air in one return. If I called for a service call, is there specific stuff I should be making sure they do to verify they are identifying and resolving the issues.

A lot of great people on this forum, not so much at the pool store.
 
You have a lot of hose clamps. Any one of those could be leaking air which may explain the air in the returns. Those are union valves correct? Those too are subject to air leaks.

Does the heater connect to the "hot" and "cold" lines?

To use the heater, do you shut off the valve in the middle and turn both of the other two on?
 

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