Recirculating pump for residential system pipe connections.

[Michael P Reilly]

Hello all. I just bought a Watts Recirculating pump to install. In the picture below is the normal configuration of how the system should be piped with this pump shown in the upper diagram. I however have a pipe loop available that terminates at the last fixture. I am wondering if I can minimize the "warming of the cold side" effect of the cross over valve by connecting it as shown in the lower diagram.

Secondly I have some concern over what material the pump is made of. One Amazon description says aluminum but that would be unusual for a pump wouldn't it? Most things I read say they are usually Cast Iron, Brass or Stainless Steel. I did a magnet test and there is some mild attractive force but barely enough to hold the magnet. My concern is that I am told Cast Iron is not the right choice for this install scenario but this scenario is exactly how the installation manual want this pump installed.

Any help is appreciated.

 

[Jeff H Young]

dedicated return line is superior use that line. Cast iron very magnetic brass not at all some stainless has slight pull I think.
Contact Watts or read your spec sheet to find out if you bouyght the wrong pump .

 

[Sponsor]

 

[John Gayewski]

If you have a dedicated return line use that with an aquastat or constant recirc. Generally the pump would be put on the recirc line and not the hot supply line.

 

[Michael P Reilly]

dedicated return line is superior use that line. Cast iron very magnetic brass not at all some stainless has slight pull I think.
Contact Watts or read your spec sheet to find out if you bouyght the wrong pump .

It isn't quite a dedicated return line. It does not make it all the way back to the water heater but it does bypass all of the fixtures.

Having looked at several pump reviews, sales descriptions and a couple manufacturer responses in amazon customer questions there were a few different claims of the material but several of them said it was cast aluminum so I think that may be the true answer.

 

[Michael P Reilly]

If you have a dedicated return line use that with an aquastat or constant recirc. Generally the pump would be put on the recirc line and not the hot supply line.

The return line is not really a dedicated return. I did not have access or the ability to get all the way back to the water heater or the main supply line. The return pipe only goes about 80% of the way back and then ties back into the cold trunk line under the house. So I am installing the recirc pump system exactly as the instructions say to do it, with the pump on the hot supply right above the water heater and the sensor valve under the farthest sink. The only difference is instead of connecting the sensor to the cold supply on that last sink which would introduce some warm water at the cold tap on that sink, I am connecting it to the return line so the warm water allowed to leak into the cold supply bypasses the fixtures and has a much longer pipe to dissipate the heat in before it would get back to any of the taps.

 

[John Gayewski]

The return line is not really a dedicated return. I did not have access or the ability to get all the way back to the water heater or the main supply line. The return pipe only goes about 80% of the way back and then ties back into the cold trunk line under the house. So I am installing the recirc pump system exactly as the instructions say to do it, with the pump on the hot supply right above the water heater and the sensor valve under the farthest sink. The only difference is instead of connecting the sensor to the cold supply on that last sink which would introduce some warm water at the cold tap on that sink, I am connecting it to the return line so the warm water allowed to leak into the cold supply bypasses the fixtures and has a much longer pipe to dissipate the heat in before it would get back to any of the taps.

Sounds better than the way its usually done.

 

[Jeff H Young]

I think its easier for you to figure out what your pumpis made out of than me I dont even know the model number ? Alumunum sure aint magnetic. you said its somewhat magnetic.