Munchkin Maintenance

MikeG

I have a Munchkin 80M propane fired boiler.  I need to do the maint and cleaning.  Is there better more comprehensive information on  the procedure than what is in the I/O manual?   In my area everyting is pretty much forced air and the Munchkin is rare. Not a whole lot of hydronic work unless you count all the wood fired out door boilers popping up.  I'm not not tech but I can handle the cleaning.  What I'm looking for is a better guide on what parts have to be replaced and what to have on hand "just in case" and more of a step by step procedure that others have found that works. I've read threads on different approaches.   I also have to make sure I plan this out since I have to order parts from an out of town distributor.  I don't want to tear into this and find out I should have this part or a gasket on hand. Heat wouldn't be an issue but it also services an indirect. I have a combustion anaylzer.  During the commissioning the LP company tech used my anaylzer to check for proper set up at least he knew how to use it, but he didn't have one.  He was told it wasn't necessary since it's new.  I found this same philosophy with most of the the installers of heating equipment im my area.   Thanks in advance for any help and guidance.  Mike

Alan (California Radiant) Forbes

Munchkin

When servicing them, I have these parts on hand:



- refractory

- target wall

- burner gasket

- spark igniter

- rectification probe

- low water pressure switch



These are the parts that get most of the wear and tear.



I service mostly natural gas units and imagine propane to run quite a bit dirtier.



I've found that removing the entire gas assembly, from the gas inlet to the fire box cover is the easiest way for servicing, especially when you have to replace the blower motor.  There will be plenty of cables to unplug, so keep track of where they all go.

MikeG

Munchkin service

Alan

How often do you find it necessary to replace the target wall and refractory?  Are some units just more prone to this or do you find after X number of cleanings it needs it?  Do you use anything special as far as a cleaner other than what HTP recommneds like CLR?  It is propane so I expect to see more crud than Natural gas fired units.  This boiler hasn't had any issues and I'm trying to keep it that way.  Thanks for any tips, techniques and word of wisdom.   Mike

Alan (California Radiant) Forbes

Munchkin

Mike:



I replace them unless they are perfect, so that means I replace them 90% of the time.



It's surprising how different the units show their wear; some are absolutely clean after 10 years of service and others are filled with debris and full of wear.



Use the CLR as directed.



I also unscrew the 4 screws (a **** to remove) that secure the burner, rinse the burner under a strong water spray, dry it off well and install a new burner gasket. I make sure the screws and the stainless steel around the holes on the burner are clean.  Somewhere I heard that the screws are an important grounding for the unit.

Steve Whitbeck

CLR

I wouldn't use CLR or any acid. Just use clean water and a brass bristle brush.

On LP you get a buildup of junk on the sides of the bottom pan that You can't clean off. The CLR will soak into this junk and eat through the Stainless Steel bottom pan.

I know that the factory says to do this but they also say a concentric vent is OK.

Oh and they say it is OK to set the boiler on the floor.

MikeG

Munchkin

When you say you replace the target wall and refractory 90% of the time is that on an annual service?  I know it will keep you from having to come back for a service call.  In the scheme of things the parts are not that expensive. If you are seeing that in natural gas units  I'm sure I will see more in my propane unit.   I'm sure that is why we see so many references to the "high maint requirements" on modcons in postings.  People will spend 40K on a car with all the electronics and won't spend a few bucks to maintain a piece of equipment that heats their house and provides hot water.  I'll have to order the parts from the distributor and hope I don't find anything else. I'll have to think about the CLR issue.   Thanks   Mike

Alan (California Radiant) Forbes

Munchkin

I recommend a regular maintenance schedule to my customers, but only hear from them when their boiler stops working and flashes an error code, typically every 4-5 years.  So no, I do not have to replace the target wall and refractory every year.  It is a good idea to have them on hand, though.



I spray down the heat exchanger (HX) coils with CLR and let it sit for 15 minutes maximum and then rinse with fresh water.  That short amount of time is enough to clean the surface of the HX and no more.