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Munchkin Boiler 80M

A_D_Flood2020A_D_Flood2020 Member Posts: 11
edited January 2020 in Gas Heating
When the house was built in 1996 I had an Apollo Heating System. This system was not heating our home enough so we installed a Munchkin 80M unit that is about 15 years old. The past few years it has been making a groaning noise when starting up. It finally died this week. I was getting an error code F09. After some troubleshooting I decided to open it up. I have posted pictures of what I found. The back plate is damp. I wanted some advice on whether to replace parts or get something else. This unit heats my downstairs main floor only. This past summer I had to replace my upstairs AC unit and went with a Trane XL16 heat pump. Should I just replace the main floor AC unit (which is 23 years old) and get a heat pump. I still have a hot water tank in the garage for my water.


  • ch4manch4man Member Posts: 236
    it appears your question is repair or replace. given the age and condition and the costs of replacement parts smarter money is on replacement.
    depending on the answer you wanted to hear, your welcome or I'm sorry.

    just my 2 cents
  • ZmanZman Member Posts: 6,315
    If you are planning to revive the Munchin, the work should be done by a qualified tech. Munchkins are nice little boilers but it is super important that they are properly tuned using a combustion analyzer and maintained regularly. I suspect yours had neither.

    As for the question on switching to forced air, is the Munchy heating your floors or do you have baseboards?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    The Munchkin is for down stairs heat only now.
  • ZmanZman Member Posts: 6,315
    edited January 2020
    In floor heat?
    What climate?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • unclejohnunclejohn Member Posts: 1,689
    You most likely have a clogged drain. Clean the heat exchanger and flush out the drain and replace the insulation on the door and the back wall ect. It appears to be just lack of maintenance. Those boilers do require a lot of TLC.
  • HomerJSmithHomerJSmith Member Posts: 1,080
    edited January 2020
    If the heat exchanger is good, it would be more economical to replace the parts that are needed.

    Parts that are needed:
    Back Refractory-(ceramic target wall)-7250P-160
    Front Burner door refractory- 7250P-161
    Burner Tube gasket-7250-070

    Other Possible Part That May Be Needed:
    Spark Electrode-7259P-958 (unless HA model)
    Flame Rectification Probe-7250P-049
    Burner Tube-7250P-248
    If they can not be cleaned or show damage.

    You might try to get parts from:

    I would wonder whether you had concentric venting. How about a picture of an open boiler cabinet to see what the condition of the inside of the boiler cabinet is and the vents that exits the house.

    There are other things that need to be done besides a through cleaning. Combustion Analysis with a recently calibrated meter. Changing the Post Purge on the blower from 25 sec. to 100 sec. Making sure that the Honeywell gas valve isn't touching the back of the black cabinet.
  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    WOW, thanks a bunch. I will get some help with this. I will take additional pictures tomorrow, I was out of town all day. I do have two large vents out of the back of unit.
  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    If the refractory is wet doesn't that mean the exchanger is bad?
  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    If I do need to replace the unit, can you give me some recommendations? I have a new Trane unit upstairs which supplies my heat and air. On my main level I have this as mentioned. I was told a unit like this supplies heat better that a heat pump. My ac unit downstairs is 23 years old and I thought maybe I should just replace it with a heat you can see I dont know what to do..):
  • HomerJSmithHomerJSmith Member Posts: 1,080
    edited January 2020
    A wet refractory doesn't necessarily mean the heat exchanger is leaking. A condensing boiler creates water in the combustion process. This water drains out of the bottom of the boiler. If the drain is plugged water will build up in the combustion chamber and the refractories will get wet. This is why you need to clean the Munchkin combustion chamber between 3 & 4 yrs. I suspect yours has never been cleaned.

    If the heat exchanger is leaky, with the boiler supply water shut off, one would expect a drop in water pressure over time. Sometimes the heat exchanger will squirt water out of a hole which is visible. A leaky HX would necessitate a new boiler.

    How about a close up picture of the inside case, one not so far away. Maybe several pictures.
  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    Thanks again for all the great feedback. I can across this site and hoped I would be able to find some help.

  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    My unit does squirt water out. We have a bucket to the left side. I noticed also the plates on the front were rusted.
  • SuperTechSuperTech Member Posts: 1,538
    I'd say that boiler is toast. Looks like a really poor quality installation, without primary secondary piping.
  • HomerJSmithHomerJSmith Member Posts: 1,080
    edited January 2020
    Ya, that's pretty bad. One of the worst that I have seen. It just reeks neglect. I hate to say it, but I think that I would go for a new unit. There is a lot wrong with the initial installation, too.

    I service some units as old as yours and they are so clean, you could eat off them, almost.

    Is that boiler in a laundry room?

    That water going into that 5 gal bucket is condensate being produced in the combustion process, which is normal. Depending upon how cold it is outside, your boiler would produce up to 5 gal of water a week. That's why it's called a condensing boiler. It condenses water.
  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    Thanks for all the great comments. You are correct no maintenance on the unit, the person that installed it didnt recommend anything. I guess I should have asked. This tech. worked for Trane so I thought the installation was correct. In the past ten years I have been overwhelmed. First I lost my job due to plant closure after 21 years of service. Lost my second job after 7 years...plant closure. Plus, I have been caregiver to two sick parents in there 80s. Anyway, I neglected maintenance and will pay the price. I may just tell them to put it back like it was with the Apollo system heating. If I do decide to replace the unit do you all have any recommendations? On the site Jupiter Heating it has a Elite Premier Boiler as a replacement.

    Consumer Reports.
    Buying Guide

    Results in the following chart are gathered from Consumer Reports’ 2018 Winter and 2019 Summer Surveys of 4,543 boilers, owned by members who purchased a new unit between 2003 and 2019.

    Our predicted brand reliability ratings are based on a statistical model that estimates problem rates within the first 10 years of ownership, for boilers that are not covered by an extended warranty or service contract. We also adjust for the number of months per year that boilers are used. The median number in our survey was 7 months. Higher ratings are indicative of better reliability. Brands receiving a red or orange rating cannot be recommended by CR at this time.

    Predicted Reliability
    BURNHAM 9 / 10

    NEW YORKER 9 / 10

    SLANT/FIN 9 / 10

    BRYANT 8 / 10

    PEERLESS 8 / 10

    BUDERUS 7 / 10

    WEIL-MCLAIN 7 / 10

    WILLIAMSON 7 / 10

    LENNOX 6 / 10

    VIESSMANN 6 / 10

    CROWN 5 / 10

    LOCKINVAR 5 / 10

    DUNKIRK 4 / 10


    UTICA BOILERS 4 / 10

    TRIANGLE TUBE 2 / 10

    Sources: Consumer Reports' 2018 Winter and 2019 Summer Surveys

    Owner Satisfaction

    BRYANT 9 / 10

    BUDERUS 9 / 10

    LOCKINVAR 9 / 10

    VIESSMANN 9 / 10

    WEIL-MCLAIN 9 / 10

    WILLIAMSON 9 / 10

    BURNHAM 8 / 10

    NEW YORKER 8 / 10

    PEERLESS 8 / 10

    CROWN 7 / 10

    DUNKIRK 7 / 10

    TRIANGLE TUBE 7 / 10


    LENNOX 6 / 10

    SLANT/FIN 6 / 10

    Sources: Consumer Reports' 2018 Winter and 2019 Summer Surveys
  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    My unit is in garage, it does look messy. As you can see that I have this Apollo hot water tank. When tech put my boiler in he said to just leave that to heat my domestic water. My question is do I need one that big if I buy a new boiler? Can a boiler take care of my heating and hot water needs? Should I just replace my downstairs ac unit (24 years old) and get a TRANE XL16 which would give me heat? Or should I just repalce what is broke? If you were me and funds are limited what would you do?
  • SuperTechSuperTech Member Posts: 1,538
    I would replace the boiler, due to such a poor piping job it probably never worked that well. If the water heater is more than ten years old I would consider replacing it with an indirect tank that works off the new boiler.
  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    Do you have any recommendations?
  • hot_rodhot_rod Member Posts: 14,386
    I think all the common boiler brands have good products, local support and recommendation may help.

    For mod cons Lochinvar, HTP, Triangle, IBC, NTI, Viessmann, Triangle Tube, Burnham, SlantFin, to name some of the most common.

    Lochinvar and HTP have been my main brands, great factory and local rep support in the areas I have worked.

    There are something like 65 brands and models of mod cons available!
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • mattmia2mattmia2 Member Posts: 2,297
    what is that 1/4" gas line going to? Is this natural gas or propane?
  • mattmia2mattmia2 Member Posts: 2,297
    And what is this boiler heating, is there radiant tubing in your floor, is there fin tube baseboard around the walls? Does it heat a fan coil in an air handler?
  • HomerJSmithHomerJSmith Member Posts: 1,080
    A_D_, if money it tight and the heat exchanger is intact, I would rebuild the boiler and have a professional do a combustion analysis on the boiler. Ask if they have the software to increase the post purge to 100 sec.

    I suspect that the boiler is connected to concentric venting from the rusting on probes. Why so much rust and corrosion? Why is the control module just laying there?

    The Munchkin is supposed to have a 3/4" pipe gas supply line to the boiler. A corrugated flex line has to be fairly large to meet that requirement. Yours is too small.

    Fix what is wrong, change the concentric vent if you have one, and clean it up. Then you may get many more years of service out of the boiler. You have to decide the best course of action.
  • mattmia2mattmia2 Member Posts: 2,297
    If it is propane the size of the line can usually be much smaller given the higher energy content of the gas and the tendency to run the systems at a higher pressure than natural gas.
  • A_D_Flood2020A_D_Flood2020 Member Posts: 11
    Thanks for all the great feedback. I use propane gas. The boiler was replacing the Apollo water tank because it didnt work very well. The Apollo still heats my domestic water. Boiler does heat coils in an air handler under in the crawl space. I don't know if the boiler is connected to concentric vent... From the pictures I have posted it has vents going outside. I dont know why it has much rust on the probes. I took it apart and laid controls on top.

  • clammyclammy Member Posts: 2,603
    edited January 2020
    I have the wall hung version of that boiler and from the looks of yours it has not been service in a while and I highly doubt the condensate traps has been flushed out being the way it sitting mainly because of the deteration of the front and rear refractory due to condensate not draining out of the heat exchanger most likely the trap under the unit is partially clogged ,this is why there a lot of corrosion on the flame rectifier and spark igniter . The installation does not look to good either being they where not familiar with the unit and left no access under the unit to remove the trap and if the heat exchanger is what’s leaking then your done if not it would still be some money to cleaned and functioning properly . HTP makes a fine line of boilers like all these types of boiler they require proper piping and pumping to insure proper function and all of these type of boiler also require combustion test to ensure there are operating proper including the unit has the proper gas pressure and does not experience pressure drops .Depending upon where u are located a heat pump may not be the greatest option depending on how cold it gets in your area . One finally side note there is usually a drastic price difference between ones who are familiar and install and service these unit over those who just install and do not set up or service and are never heard or seen after the install . Chose your installer wisely and make sure they have combustion anyalizer and manometer to set it up properly and that they will return yearly to perform manafacture suggested maintenance peace and good luck clammmy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating

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