Where can I get a low-speed 12v circulation pump?

[tomandsophie]

The question is in the title. I want to buy a low-speed, low power, 12v heating circulation pump. Ideally 3l/min or less. Also ideally £100 or less. Any ideas?

[John Orentas]

If the pump is a simple impeller type and not a displacement type just fit some kind of resrictor valve and experiment with the principle. Or bash the pipe a bit flat !

[tomandsophie]

Ok John, a good idea. Thankfully I installed a gate valve above the pump, so I might experiment a bit with restricting the flow with that.

[ChrisPy]

You are much better off either using a pulsed supply as suggested by ChrisW or a bypass, neither of which imposes a significant load on the pump or results in wasted energy.

 

Partly closing a gate valve just makes the pump work harder for less effect. Mind you it will have the advantage that all the energy wasted at the restriction will be converted into heat, so you will be using your 12V battery to heat the water.

[JohnT]

Hi Tom &Sophie

I have seen aquatic(fish tank) pumps at this kind of output and often 12v(many of them plug into a 240-12v converter), worth a look.

Or as a temp measure a windscreen wash pump?

JohnT