Increased filter pressure decreased return

I installed a sungrabber solar heater mat and am concerned. When I run the heater the pressure on my filter raises about 5 psi (14 psi normal, 19 psi when heater is going) and the return to the pool is much weaker. I have it set up with ball valves so I can turn it on and off. I used 1 1/4" black poly hose for the run. The fittings on the unit are 1 1/2", I used fenco rubber adapters to connect. Is the change in diameters causing the increased pressure? Is this going to cause damage to the filter or the pump motor?

Mark

I am sure experts will be along with additional info as I do not have one of these units but the smallest standard size for pool equipment is 1 1/2 inch so it may be that 1/4 reduction. I am sure better info to follow :-)

Mark,

Anytime you add resistance to the pressure side of a constant speed pump, the pressure will increase.

It could be from adding smaller eyeballs at the reurns, a dirty filter, or, in your case, the resistance of all that piping in your solar heater.

It will not hurt your pump.

My solar setup causes about a 7psi or so increase. However, it doesn't feel like the return flow is reduced. I have 2" pool piping and 2" solar piping.

You may want to put a diverter valve so that part of the water goes to solar and part goes straight to return. One way to tell if you are getting enough water through the solar is to feel the panels when they are in direct sunlight. If solar is on, the panel should be cool to the touch. If it is hot, there isn't enough water going through the solar. So, if you put in a diverter valve, you can adjust/test/adjust the valve until you are getting just enough water through the solar to heat effectively, but also not increasing your pressure too much (which might hurt the panels - but don't panic). Generally, most panels need about a 4 to 5 psi increase to work effectively and most can handle a 10psi increase without issues.

I have it set up with ball valves so I can divert only part of the flow, I will try that and see if i still notice a rise in temp.

Thanks

My 1 HP pump/filter output is split 3 ways. Returns, field solar (homebrew) and 4x20' mat. Solars feed into the deep end from two hoses weighted down under the diving board out of the way. I maintain about 10-15 GPM thru the solars and that is plenty. Get max overall flow and no pressure rise, in fact a drop because of less overall flow resistance.
Al