High pressure when solar heater is on

Dwiessner

Active member
Apr 28, 2017
32
Murrieta
#1
Hi all,

We just bought a house with a pool and we are trying to learn how to care for it. I just cleaned the filter cartridges, and the pressure is about 15 psi. When I turn on the solar heater, the pressure jumps to about 30 psi. Solar panels are on the roof of a 2 story home. Is this normal or expected? Will it cause any issues? If this isn't normal, any thoughts on what the cause could be?

Thanks!
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,292
Pleasanton, CA
#2
Normally, a well designed solar heating system should has psi rise of 5 or less so 15 is quite excessive. Can you give us some more details:

Pump make and model

Size and number of panels

Plumbing size and distance to panels

Does the pressure gauge go to zero when the pump is off?
 
OP
OP
D

Dwiessner

Active member
Apr 28, 2017
32
Murrieta
#3
First choice 56 frame champion pool pump.

Waterway pump motor

No clue how big or how many panels. They are 25 feet off the ground.

Probably 50 to 100 feet from pump to panels

2 inch pipe

Guage goes to zero when off

- - - Updated - - -

Looking at Google earth, there are 8 panels, 5 large, 3 small.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,292
Pleasanton, CA
#5
Assuming the panels are plumbed in parallel, there should not be a 15 PSI rise with solar so I would start investigating the cause of the pressure rise. My first instinct is to look at the check valve on the return side of the plumbing. If you have one, and most systems do, and if it is serviceable (i.e. the cover comes off) make sure the flapper has not come loose. If you have a older style check valve, it may be difficult to inspect it. Can you take some pictures of the pad equipment and the plumbing going to and from solar?

Also, what is the pump motor HP and SF ratings?
 

Pool Clown

In The Industry
Sep 5, 2008
1,836
Silicon Valley, CA
#6
Also, panel(s) could be obstructed due to either debris that got past the filter, or if the panels had many leaks (over time). One way to repair a leak is to abandon the capillary tube in question. If you get enough of them, it will begin to affect flow.

Two stories, and 100 feet does put extra head on the pump.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,292
Pleasanton, CA
#7
Once primed, the two story lift is no longer an issue. There is both static head loss on the lift and static head gain on the drop so the only head remaining is that due to dynamic head in the plumbing.
 
OP
OP
D

Dwiessner

Active member
Apr 28, 2017
32
Murrieta
#8
Assuming the panels are plumbed in parallel, there should not be a 15 PSI rise with solar so I would start investigating the cause of the pressure rise. My first instinct is to look at the check valve on the return side of the plumbing. If you have one, and most systems do, and if it is serviceable (i.e. the cover comes off) make sure the flapper has not come loose. If you have a older style check valve, it may be difficult to inspect it. Can you take some pictures of the pad equipment and the plumbing going to and from solar?

Also, what is the pump motor HP and SF ratings?
Sorry, I'm new to all this, so it's Greek to me. What is a check valve? How do I know what side is the return side? I'll try to post a picture soon, but the plumbing is a huge cluster of pipes, so I don't know what to take pictures of since I don't know what they do. The solar goes underground, to the house, then 2 pipes up to the roof. There are 2 panels near where it went up, then 6 panels I think on the other side of the house.
 
OP
OP
D

Dwiessner

Active member
Apr 28, 2017
32
Murrieta
#9
Also, panel(s) could be obstructed due to either debris that got past the filter, or if the panels had many leaks (over time). One way to repair a leak is to abandon the capillary tube in question. If you get enough of them, it will begin to affect flow.

Two stories, and 100 feet does put extra head on the pump.
How would I clear debris from the panels? I had the solar company that installed it out to dewinterize the panels last month and they didn't mention any prior repairs or issues with pressure. I don't know, I'm lost.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,292
Pleasanton, CA
#10
Sorry, I'm new to all this, so it's Greek to me. What is a check valve? How do I know what side is the return side? I'll try to post a picture soon, but the plumbing is a huge cluster of pipes, so I don't know what to take pictures of since I don't know what they do. The solar goes underground, to the house, then 2 pipes up to the roof. There are 2 panels near where it went up, then 6 panels I think on the other side of the house.
A check valve will look like one of the following:

pool check valve - Google Search

The supply side of solar is closest to the pump pipe wise. Meaning water travels from the pump to the filter to solar supply and returns after going through the panels.

How would I clear debris from the panels?
Not easy to do so let's hope that there is not any panel blockage. That can only happen if debris bypasses the filter. What kind of filter do you have (sand, DE or cartridge)?