LsFarm wrote:No stress on the pump or motor,, these type of pumps can run at a full stoped flow and be OK... If you put an aquastat in the circuit, you risk getting some VERY hot water in the loop in the stove... If you keep it moving it will not have a 'hot spot' and boil and flash to steam... blowing your PRV... Keep the water circulating.
These small cartridge circulators cost about the same as a light bulb to run... a taco 007, a 1/25hp pump burns .78 amps... about like a 100 watt light bulb.. the taco 002 is [I think] a 1/40hp pump, burns half that current... just about nothing.. and you won't need to restrict the flow very much... that deal about circulating too fast doesn't hold up well in practice... circulate the water... it gets heated with each pass, the faster each pass comes around the more heat is picked up... I could go on about this, but a high rate of circulation helps create turbulence, eliminate stratification layers [laminar flow ] which is bad for heat transfer..
The small taco pumps are often available for about $40 on Ebay.
Hope this helps.. Greg L
ahhhh.... thanks for the explanation.... ok, so you had me up until you said "eliminate stratification layers [laminar flow ]"..... wiki: http://en.wikipedia.org/wiki/Laminar_flow
Are you saying that some of the hot water could "stick" to the pipes and the cooler water could circulate inside of the outer "laminar" layer? If that's the case, in my setup I would want to set my differential temperature to 15F or 20F so I will get more circulation in the water correct? Sometimes my circ. pumps only kicks on for ~15 seconds or so before the aquastat kicks it off.