I'm reporting on my own personal experience with my 140M Munchkin boiler, installed in my home about 5 yrs ago.

Efficiency on the Munchkin is, like most Modulating Condensing boilers, dependant more on a low return water temperature system design. Following that parameter, it appears on a par with a Triangle Tube Prestige boiler.

Reliability? OH MY GOD. This boiler has caused me more trouble than the most complicated systems than I've ever designed, installed, or maintained.

Year 1: No problems, simple, quiet operation.

Year 2: Beginning of Fault 09 Hell. Typified by the control board failing to see that the burner has, in fact, lit up. Disassembled, cleaned per instructions, flushed condensate trap and heat exchanger. Reassembled, Fault 09, lockout, hit reset, repeat perhaps 20-30 times while hearing the burner light off each time and watching the pretty flames on the burner cone that would not be recognized by the control board. Finally, the little green light comes on during an ignition trial and all's well for another year.

Year 3: Fault 09 Hell again. This time replaced the control board on recommendation from Tech Support "Sorry Mr. Rowe, your equipment's no longer covered by warranty, you'll have to shell out the $$$$ for the new board yourself" New board installed, Hit reset button for about 4 hours, until amazingly, the unit fired off w/o a hitch.

Year 3.5: Inducer blower flew apart internally. No heat....AGAIN....in my own home.....another $$$$ for a new blower assembly. Long talk w/ tech support "yes Mr. Rowe, we realize that the blower assembly design was changed (which I took to mean was found to be defective and revised), but you're out of warranty period and will need to pay for the new blower.

year 4: Fault 09 Hell again, ending with Fault 11 which signifies that the control board has gone beyond not recognizing the flame signal on ignition to now seeing a flame signal at all times, causing an instantaneous (rightly so!) lockout. Paid another $$$$ for a new control board. While spending the day resetting the control over and over, I spoke again with Tech Support trying to find out exactly WHAT's CAUSING THE FAILURES. Described the installation in depth, gave voltage readings, ohm readings etc. for nearly 2 hours. Suddenly, with no changes being made, the boiler lights off and all's supposed to be well. "Sorry Mr. Rowe, we understand that you've had a bad experience with our boiler, but we won't be covering any of this under warranty or offering you a replacement boiler. We do feel that the problem has now been corrected"

Today: My boiler's gone out....again....it's been acting up this week and finally went from Fault 09 Hell to Fault 11 Failure. Looks like if I want take a hot shower and want my family happy, I'll be shelling out yet another $$$$ for control board #3.

It's my belief, and has been my experience, that long before this point any other boiler manufacturer would have sent me a new boiler, fully covered under warranty along with a factory rep to commiserate and toss an apology in. Not so thusfar with HTP. I had expected them to man up and work with me to straighten this out. Since they have been unwilling to do so, My own belief is that no sane person should ever expose themselves to the possible nightmare that I've had!

It's quite sad, because the basic design seems sound, the piping is straightforward as long as you maintain proper flow through the boiler which usually means decoupling the boiler flow from the system flow. I'd love for Heat Transfer Products to work this out and be able to post glowing reviews of the Munchkin, and the company as a whole. At this point, the only thing that would change my mind would be a new, fulling functioning Munchkin.

We have had the Munchkin M199 boiler system installed for approximately 6 years and have had nothing but problems with it. The blower was replaced within the first year, the igniter system was replaced within 2 years, the computer controller was replaced, etc. If fact, everything on the unit was replaced within 3 years and we have continued to have F09 faults for the last 3 years. We have never had hot water for more than 1 shower. Our gas bill has been extremely high for entire time since we installed the Munchkin unit. The local HVAC dealer/installer has not been able to solve the problems.

Editors comments - Extremely high gas bill? I would be interested in seeing the bills and posting them on this website to show people.