Pump for solar heater - anything special needed?

[autocrat]

Hi all,

The pump for the 2nd-floor solar has died, not a big deal in itself. But. The bloke from the pool shop reckons I need a pump specifically built with solar in mind, something about heat-resistant parts. The old one is a Davey Power Ace 150 (not 150CR), and is probably 15 years old and has been running just the solar (it has its own inlets).

Is there any truth in that? Apart from it not seeming very likely that very hot water is going to be sucked back down from the roof, will any standard pool pump handle it?

Thanks.

 

[duraleigh]

Welcome to the forum. :lol: MOst solar setups simply use the pool pump to circulate through a solar system. Why does yours require a second pump?

 

[UnderWaterVanya]

The pump for the 2nd-floor solar has died, not a big deal in itself. But. The bloke from the pool shop reckons I need a pump specifically built with solar in mind, something about heat-resistant parts. The old one is a Davey Power Ace 150 (not 150CR), and is probably 15 years old and has been running just the solar (it has its own inlets).

Is there any truth in that? Apart from it not seeming very likely that very hot water is going to be sucked back down from the roof, will any standard pool pump handle it?

I don't think that pool guy knows what he is talking about.

As mentioned by the previous poster the majority of solar installations that I have read about here are setup with the main pool pump as the source for the flow.

 

[mas985]

If plumbed correctly, hot water should not go through the pump anyway. A check valve should be placed between the filter and the solar valve so when the water drains, the check valve prevents it from going through the filter and pump. Otherwise, the debris in the filter would be back flushed into the pump.

 

[autocrat]

Thanks for the replies.

The second pump/inlet is just the way it was set up when we bought the place - it doesn't go anywhere near the filter. The pump is a good distance from the pool and also from the house, and the solar setup on the roof is up pretty high, so I assume they thought it'd be a better idea to have a second pump. Whatever, that's the way it is.

I'll make sure there's a check valve.

 

[jblizzle]

If all you have is a suction line to the pump, up to the solar and then back down to the pool return ... there is no point in having a check valve anywhere.

This is likely a low head-loss system (depending if the solar is in parallel (as it should be) or series. So I would not think you would need a very large pump for this setup.

Where are you located? The pumps available to you may not be the same in all parts of the world.

Hopefully Mark can suggest what size pump you need ... although with no pressure gauge in the system, might be a bit tricky.

 

[autocrat]

If all you have is a suction line to the pump, up to the solar and then back down to the pool return ... there is no point in having a check valve anywhere.

This is likely a low head-loss system (depending if the solar is in parallel (as it should be) or series. So I would not think you would need a very large pump for this setup.

Where are you located? The pumps available to you may not be the same in all parts of the world.

Hopefully Mark can suggest what size pump you need ... although with no pressure gauge in the system, might be a bit tricky.

The old pump was 1HP. Given how long it was running, and how there are no issues with any of the plumbing or the panels, I'd say it is about right. I'm in Australia - it gets hot up on the roof, up to 70C according to the sensor, so I just wanted to make sure that we didn't need a special antikryptonite works-in-space model.

Thanks for help.