I have a rheem power vent 21vp40e-1a my problem is a decline in the amount of hot water I get out of it. Once it begins to heat, the burner will light run for a few seconds and then shut off this will continue for a long time, then eventually it will stop. The amount time that the burner lights varies but it's usually less than a minute. I've checked for obstructions of the pvc vent, and I've bypassed the vacuum switch by jumping the wires, and the problem continues anyone have any more advice on this or dealt with the same issue?

It sure looks like either poor supply of oxygen or burnt gases are not being discharged properly. Recheck these two items. Back to you. Milo

Hi Shonk

I'd recommend that you contact the technical support department over at Rheem and see if they can walk you through the steps to figure this out. Most likely, you've already banged your head against the wall enough that continuing to do it won't be very good, so make the call and talk to them... usually very helpful here!

Click on this link:

http://www.rheem.com/contact.aspx

Good luck!

Mark