Maintenance - Rinnai RC98HPi / REU-KA3237FFUS-US - blowing off burner and heat exchanger

AaronD

I need some help on a couple of the regular, vanilla maintenance items that are mentioned in the owner manual but not elaborated upon.

I have a Rinnai RC98HPi, installed December 2010 (REU-KA3237FFUS-US).

Questions:
1) When removing the burner to blow it off with compressed air, is it OK to re-use gaskets and packings? I will have to remove the gas manifold and sight glass plate. There are gaskets and packings at the joints to other mating parts.
2) To blow off the heat exchanger with compressed air, can I do this “in place”, once the burner is out, or do I need to pull that out to do the job properly?
3) If a guy was serious and really wanted to do it right, what would you do to “inspect the vent for blockages”? Should I go to the vent termination point and blow compressed air into the passages, sending any “stuff” into the unit? Or is it intended to be just a visual for obvious damage?
4) Rinnai does not mention it in the manual, but I saw that another manufacturer recommended removing the electrode to shine it up with emery cloth. Seems reasonable. Any reason not to do this?


Notes:

Installed indoors, on a finished wall in the basement. Exhaust is with the concentric UBBINK Rolux components – a short run of only a few feet consisting of two 45 degree elbows, and one 90 degree out through the rim joist. Vent termination is the Rinnai Vent Termination Kit, P/N 223177PP. Gas line and gas meter were upgraded prior to installing the Rinnai tankless unit.

Unit has been trouble free and reliable. I think the fan noise is louder than what it was on day one – reminds me of the DVD drive on our computer when it revs up, but a little louder. I blew the fan off one time, and I will do that annually from now on when I do the vinegar flush and clean the inlet filter.

Jack

I would have new gaskets on hand prior to pulling the burner. If you remove the sparker and flame rod have those gaskets on hand as well. I would burnish the flame rod with a dollar bill. If your home is really up-scale, use a 50. Emery cloth scratches the rod and makes it easier for it to become crapped up in the future. Is there a specific reason you want to pull the burner? If the unit has been working well I would pull the inducer and perhaps clean that. If it is very dirty there might be a reason to go deeper to clean the burners, but if the inducer looks good I wouldn't do it. Inspecting the vent system is typically a visual thing. Again, unless it is throwing an error code or you see something that leads you to delve deeper I'd let sleeping dogs lie. Check your manual on looking at the error code history and that will give you a look at how it has been doing.