PEX sizing issue, need 3/4 but inside diam of 3/4 much smaller!

[mpilihp]

I recieved my order for PEX to plum in my indirect hot water heater. It calls for 3/4 piping and I ordered 3/4 pex and all the needed connections but its inside diameter is smaller. The pex is 5/8 and the connections are 1/2" I didnt think this through very well. Im thinking I should have gone with 1" pex.

Will this be an issue? Should I send it back and get 1" PEX?

 

[Couderay80]

Yes, I would. Unless they specifically call for 3/4" pex. 3/4" copper is 3/4" I.D. and black pipe is slightly larger.

 

[mpilihp]

Thats what I was thinking but its alot more $ for 1" pipe and fittings. THe DHW coil in our Oil boiler im replacing this with is only 1/2" and the piping in the house is all 1/2 so this would be fine I think for that.

On the boiler piping couldnt I run parallel 3/4 pex doubling its volume? Would only need a few more parts and I have way more 3/4 pex than I need (Bought 300ft)

 

[mtfallsmikey]

Don't do it!...1/2" pipe is too small for the whole house...I know it's more $$$, but when it doesn't work right, costs even more to replace.

 

[mpilihp]

Hi Mtfallsmikey this is an existing house and has 1/2 copper for the DHW and the existing DHW coil im replacing is 1/2 copper so going with 3/4" pex is actually an increase in volume slightly. THe inside diameter of the pex is 5/8" and the fittings are 1/2" Sending everything back to PEXsupply would be a hassle and the 1" is twice as much...

~ Phil