Recirc pump….

[Tom80]

I only have a two speed pump in my project hot tub. To save dollar bucks I would like to add a 0.5hp recirculation pump, but just wondered where to put it? Do I run it parallel to the main pump but with a 1 way valve on outlet side to prevent back pressure when main pump is on? 

[CanadianSpaTech]

4 hours ago, Tom80 said:

0.5hp recirculation pump

You better make sure the flow rate is enough to support the heater and pressure switch

4 hours ago, Tom80 said:

To save dollar bucks

Not so sure you will save much by adding in a circ. Add up the costs of the circ and all the install components you will need to pay for would likely be several years of cost differential between the circ and the current set up. Circ would likely be 1.5" in/out and you have 2" plumbing so consider you will need union adapters to make it work.

Will that pack even support a circ pump? Is there a port on the side of the pack for a circ?

 Post photos of the schematic on the inside cover.

Personally I would leave well enough alone and use the economy mode and set my filter cycle duration to it's lowest setting that will allow for proper filtration for your normal use. I would also pack in some Rock Wool insulation into the open voids of the spa and up the overall R value of it. You could also fit in rigid foam board around the perimeter. Just make sure to not over do it and the pump can breath. JMO 

 

[Tom80]

Ok fair enough. Does eco mode once up to temp then just turn the low speed motor mode on as a pulse to keep the temp up? I was going to rock wool the system but did not want to jump in too far until I know the system and get it working. The controller and all electronics are not from this tub. The tub was a warranty exchange and it had a crack in the shell so I fixed it and bought it for £400. 

[CanadianSpaTech]

In Eco mode it will only heat the water during the filter cycle. The hours in between the filter cycles if there has been heat loss it won't fire the heater until the next filter cycle starts. It might only loose a degree or 2 and then only needs to fire up the heater for a short run to bring it back up to the set temp. Most heat loss is up through the cover so make sure you have a good thick cover on it or at least one that is in good condition and fits.