Advice on running circ pump 24/7

[dg55117]

Gentlemen,
You helped me a ton running in floor heat using an electric on demand water heater, 3 zones and a circ pump. In heat mode(winter) I use a thermostat that controls the circ pump so that when flow is detected, the heater comes on until the set temp is acheived then the circ pump shuts off and flow stops and heater goes into standby mode.
My question is whether it would be better to run circ pump all the time and have the thermostat control the heater. If that seems like better operation, would I just use an big 240 volt ac relay?

 

[nehog]

Additional wear... Additional cost for electricity... Personally I'd not leave it on full time.

 

[Asha'man]

I'd just run it as needed, unless you wanted to do a commercial style lead/lag setup with two pumps.

 

[rharman]

We have a recirculating pump on our water heater and the whole house is plumbed for return water. Used to have two water heaters and pumps. Pumps ran 24x7. After almost 20 years of that, sitched to a timer and our electric bill dropped like you would not believe. Then, switched to an X10 controller and we turn on the pump when we want hot water. Bill dropped even more.

Those pumps really eat electricity....