Munchkin F00 Error and Maintenance Suggestions

tothbob

I am a degreed person who can say with certainty that I know little if anything about boilers, electronics etc.

About a year ago I had an F00 on my 12 year old Munchkin 925 boiler controller (I've had it for about 3 years). I read the manual, something led me to the "no flow" portion of the troubleshooting so I did the reset and it started working and has been good for a year.

The "something" that led me to no flow was the fact that we've installed a FloLogic Water Control System that turns off all water, pre-boiler, when it senses no flow in any condo water system (faucets, dishwasher etc) after 12 hours. I've only seen the F00 once, and I don't know how long the water had been off in that particular instance (if that matters). The Munchkin doesn't always show F00 when flow has been cut, and in fact it may be resetting itself (possible?) when flow returns.

It a recent conversation about Munchkins with other owners (we have 12 in our building, all still holding up after 12+years) we talked about what can be done to extend the life of the Munchkin. Questions follow.

1) What effect does turning off the water feeding the Munchkin have? Am I looking at a potential meltdown or is there protection built it, and should I be getting an F00 to tell me the protection is working.

2) The only issues (sample size of 3 of 12) that I know of are the replacement/cleaning of the igniter (F09) and a fan replacement. What are some other common 925 issues?

3) I've talked to an owner with a boiler (not Munchkin and not for radiant heat, but baseboard heat) and he said his biggest issue was the water tank. Mine is sitting there with no signs of rust/wear etc as I've experienced on a gas fired water heater. Do these tanks fail--i.e, big time unexpected leaks?

4) Our biggest fear with the Munchkin is water damage. When it fails, is leakage (big or small) normally evidenced?

5) Are there signs of impending doom? What would lead me to replace the Munchkin before "big event" especially as I rent my place our seasonally?

6) Always good to have an experienced person "take a look" regularly but is there a set of items that should be performed to extend life?

delta T

I'm a little pressed for time, so I won't address all of these items, just number 6.

The NUMBER ONE thing that absolutely MUST be done to keep these going is to thoroughly clean out the heat exchanger EVERY YEAR. To do a proper cleaning and service check (including a combustion analysis) should take a good tech about 1 to 1.5 hours depending on how badly it needs cleaning.

If there are any leaks on the system, don't wait, fix them ASAP, no matter how small they are. Fresh water=fresh oxygen=bad news for all things iron in the system. Dirty rusty water clogs the small passageways in the heat exchanger, and then they fail. Also fresh water, if it is hard at all, introduces fresh minerals, which likewise start to accumulate on the heat exchanger and lead to the same thing.

Over the use full life of these units, expect to come to a point where you will start to replace components like gas valves, or control boards, as well as igniters and flame sensors. The gas valve, fan and control boards can be pricey, be prepared for that.

mak62

I have seen a few that needed burner gaskets,target walls and the water pressure switch clogging. You should have the heat exchanger cleaned,The condensate trap can be an issue also

tothbob

I appreciate the feedback so far. If anyone has time could you look at questions 1 and 4 as a priority. I of course welcome all comments on all questions.

kanecats

I have a Peerless...same as Munchkin. It has been nothing but trouble, and I am now looking at an F09 error code and will replace the ignitor first and if that doesn't solve it, the flame sensor. You can learn the boiler! I am a female and figured it all out, and do the work on it. I would start thinking now about what your replacement would be! I am in that process now, and not happy about the idea!

re #2-I previously had the venturi crack, and the screws that mount the sensors on the front were seized into the cover. 3 of the 4 nuts stripped out dispite the pb blaster and delicate attempts to get them out. The boiler is fussy, and after spending 5k to fix a hammer problem due to piping issues, the thing still hammered! It took a geothermal expert to confirm what I thought was wrong, and made the change for 250 bucks. Make sure you get someone who really knows boilers and piping!!