Munchkin t-80 problem

Paul Pollets

Have you removed and cleaned the heat exchanger recently? Cleaned the coil and condensate lines per mfg. instructions? You'll find these units need yearly cleaning to work properly.

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Brad King

Munchkin t-80 problem

Hi all,
Not knowing how much information this forum prefers, and with some messages titled “heating system broken” I wonder if you guys would rather have the challenge, I am providing an abridged version-complete info on request.

I am a construction pro with a self-installed system in my own house. It is an 18 month old Munchkin T-80m w / 925 controller running on propane that recently started running unreliably, and generating lock outs with mostly f-9 / 10 codes. I have now swapped the controller solving the immediate problem and on the old controller board are signs of corrosion. An acquaintance that I shared a meal with last night has a similar system (type & age) is having similar problems. His latest service person apparently has a 20yr history with HT / Munchkin and said they had problems with these units recently, particularly related to exhaust manifold leaks. They swapped out the complete boiler last week.

Is anyone aware of any of these problems?
Exhaust manifold leaks?
Corrosion on electronic components?
Broad array of error codes on controller?

Thanks for your reply(s)
Brad

Andy_6

I have seen the same thing happen. In my cases it was caused by exhaust gas recirculating back into the intake pipe. This was solved by increasing the distance between the intake and exhaust. Hope this helps.

clammy

re circulating

If the control board is looking like corrision is happening i would guess that you may have a promblem with re circulating combustion gases ,i would take a good look at your vent kit and make sure that you are not pulling combustion gases back into the fresh air inlet if you have a good digital combustion anlyanlizer i would check your air inlet with the cover on the boiler and and see if your pulling combustion gases back into the unit .I would also take a look at the installation instruction and make sure the venting is up to manafactures specs if not de ro it correctly there has been some post on re circ issues and vents not being done up to specs .I have a few of these units installed and have yet to have any promblems longest about 2 years and i do tell my custermers that the unit requires servece and cleaning each year and if they elect not to do so then they will be in all probalby be replacing the unit permaturly .If the unit is going off on f9 then it's probalby time to service and clean it also peace and good luck clammy

Brad King

Munchkin t-80 problem

Thanks for the prompt replies, gotta love the Internet

The termination is the stock combo vent for roof (vertical) application. It's a little close to a ridge but I left the stub high and watched carefully in the initial burns. In calm conditions the convection carries the exhaust gas aggressively upwards, in windy conditions the condensate does not recirculate down. I believe the exhaust vent on the cap can be extended and it will probably be prudent to add 6" or so to eliminate the slightest possibility.
Surprisingly, RT combustion analyzers are not common within my community of plumbers and HVAC subs, though they are hi-end guys and work with the HE units that should be tested. I tested the exhaust of the T-80 with kit from our local Air Quality district, where my with used to work. I'm tempted to borrow it again to test the air within the boiler case during operation.
I inspected the combustion chamber in February as part of my intial diagnostic of intake and exhaust flow and saw only a small amount of buildup in the chamber.

Brad King

Munchkin t-80 problem

Thanks for the prompt replies, gotta love the Internet

The termination is the stock combo vent for roof (vertical) application. It's a little close to a ridge but I left the stub high and watched carefully in the initial burns. In calm conditions the convection carries the exhaust gas aggressively upwards, in windy conditions the condensate does not recirculate down. I believe the exhaust vent on the cap can be extended and it will probably be prudent to add 6" or so to eliminate the slightest possibility.
Surprisingly, RT combustion analyzers are not common within my community of plumbers and HVAC subs, though they are hi-end guys and work with the HE units that should be tested. I tested the exhaust of the T-80 with kit from our local Air Quality district, where my with used to work. I'm tempted to borrow it again to test the air within the boiler case during operation (or buy one of my own).
I inspected the combustion chamber in February as part of my intial diagnostic of intake and exhaust flow and saw only a small amount of buildup in the chamber.

Nron_13

watch for chemicals and that incl;udes the wash machine and dryer in the same area as the boiler bolth allow fumes that can harm electronics

steve gates

had similar problems

with t-50's. One on lpg, one on nat. Never did figure out the one on natural gas, so changed it with a new one. No more problem.

The one on propane however... Finally changed out the tank regulator and no more problem for 4-5 weeks. Changed again, no problem for 4-5 weeks... On my third one and the call come in last weekend. Iwill keep pluggin away till fixed! Even if I can't get a rep to come by. 8 hr drive from denver.. so... shame on them.