Munchkin Help!

bobbyg_2

wow. aggressiveness is a function of properly programming the Vision 1 parameters.

The new board is the "brains" and will have to be reprogrammed like the old one. There shouldn't be any difference between the "old" board and the "new" board concerning water temperatures.

joe bristol

I have a Munchkin 199M with indirect hot water. My swirl plate melted recently and my contractor replaced it and also gave me a new board. Apparently this new board corrects the post purge time so that my swirl plate doesn't melt again. Everything seems to be working fine, but my hot water isn't that hot anymore. The contractor says its because the new board isn't as aggressive as the old one. How do I adjust the temperature of the hot water?

joe bristol

I thought that too. I think my contractor is afraid to change the temperature settings because my swirl plate melted. Is there any reason I can't re-program myself, or do I need a contractor to do this?

bobbyg_2

I don't believe it melted. It probably corroded. This corrosion is caused by not getting the exhaust gas all the way out of the exhaust pipe and into the outside. This exhaust gas is corrosive. That is why they program the post-purge cycle longer on your new board. You probably have some sort of negative pressure issue. I remember you saying in a previous post that the contractor sealed the door with weatherstripping. (This was to minimize this "negative pressure" influence on your exhaust gas).

It is the post-purge length of your blower, not your circulator (which you could be programmed by a contractor in the field).

I don't think you should do the programming. Someone with more experience knowing what all of the parameters mean should do the programming.

Hope this helps.

joe bristol

Thank you. That helps a lot. I understand the idea of negative pressure preventing corrosive exhaust from venting and thus corroding the swirl plate. I see how the increased post purge time and sealing the box could remedy that. I still don't understand what this would have to do with the temperature of my hot water. I also don't understand why my contractor seems so reluctant to try to remedy this.

[Deleted User]

The vent termination may have to be addressed. The exhaust should extend at least 12" beyond the intake. Do not terminate the exhaust behind shrubs, behind hose reels, A/C units or inside corners. I see vents not correct quite a bit. Read the directions before install. The user manual will spell out how to raise the tank temperature.

Unknown

Legal issue.

Due to scalding lawsuits, hot water temperatures are a hot issue. I set them by code, test them, inform the homeowner of the requirements, and then have them sign a statement that I informed them of the code and that I properly set the temperature. When I leave I suspect that most turn the temperature up.