Welcome! Here are the website rules, as well as some tips for using this forum.
If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
AO Smith HWH - can heating capacity be increased by changing orifice?
This is a AO Smith 50 gallon power vent unit rated at 40K BTUH operating on LP gas. It's in a very northern climate where the incoming water is bone-chillingly cold. So it takes a very long time for tank recovery - just washing a few dishes by hand kicks off a 30 minute cycle.
Seeing that the unit is rated at 46K BTUH on NG, I assumed that the power vent and PVC could handle a slight increase in flue gas temp.
I was wondering if changing the orifice is an acceptable method of increasing heating capacity? I know that efficiency will drop somewhat. The stock orifice is #48 and I was considering drilling out to a #46 - which should take the capacity up to 45K BTUH.
I'd probably buy a new orifice and drill it out, rather than sacrifice one that is working - just in case. It looks like it's a brass hex 3/8" type - is this a standard orifice or will I need an actual AO Smith part ?