hot water recirc line location

[BobinWA]

I have a Laing undercounter recirc pump that finally went out. The replacement cost is pretty high, and we didn't really like the mixed water on the cold side, so I'm thinking about just tapping into the hot water line somewhere it's easy access and running a pex 1/2" line back to a real recirc pump at the hot water heater. The heater is located on the far side of the garage, with pex under/in the slab to connect to the house, so just getting hot water across that span would greatly help.
Other than not getting a full house recirc, is there a problem running the recirc piping from the middle of the hot water run as opposed to the end of the furthest run?

What are some of the better whole house pumps to use? I'd like a timer, at least.

Are there any specific things I need to be on the lookout for as I work through this project?

Thanks,

 

[Breplum]

You have to take care with 1/2" PEX because the i.d. causes a fair amount of friction. With the great recirc pump built in to the Navien water heaters we install, the mfr says not to use 1/2" PEX. 1/2" copper is ok though.
of course the major mfrs of pumps are better than the weird name chinese but you could get lucky.

 

[Sponsor]

 

[BobinWA]

Thanks for this useful info - running a 3/4" pex will not be a problem.

Regarding recirc line location - are there any problems with a tee for the recirc line that is located somewhere in the middle of one of the hot water branch circuits?

 

[Breplum]

Thanks for this useful info - running a 3/4" pex will not be a problem.

Regarding recirc line location - are there any problems with a tee for the recirc line that is located somewhere in the middle of one of the hot water branch circuits?

No problem, wherever you can, the minimal pump flow will move it properly. Do install a check valve if appropriate if you return the recirc line to the cold side supply feed. We always use isolation valves and bleeder hose bibbs at any pump.

 

[BobinWA]

thanks again, Breplum. Already have a check valve for return line to cold water supply side.
Have a great day.

 

[christopherdbrown]

I have a Laing undercounter recirc pump that finally went out. The replacement cost is pretty high, and we didn't really like the mixed water on the cold side, so I'm thinking about just tapping into the hot water line somewhere it's easy access and running a pex 1/2" line back to a real recirc pump at the hot water heater. The heater is located on the far side of the garage, with pex under/in the slab to connect to the house, so just getting hot water across that span would greatly help.
Other than not getting a full house recirc, is there a problem running the recirc piping from the middle of the hot water run as opposed to the end of the furthest run?

What are some of the better whole house pumps to use? I'd like a timer, at least.

Are there any specific things I need to be on the lookout for as I work through this project?

Thanks,

Running a recirc line from the middle of the hot water run instead of the furthest end shouldn't cause any major issues, as the pump will still circulate water, though it might take a little longer to get hot water at distant fixtures. However, be cautious when using 1/2" PEX, as it can cause friction and reduce flow 3/4" PEX or copper is preferred for better performance. Adding a check valve when returning the recirc line to the cold water side is essential, as mentioned. For a whole-house pump, look for a reliable brand with a timer and consider isolation valves and bleeder hose bibs for easy maintenance.