HTP Honeywell Boilers | FurnaceCompare®

HTP Honeywell Boiler Overview

The Munchkin Honeywell series gas boiler was manufactured by the company Heat Transfer Products (HTP) until 2002. Munchkin boilers occupy a small amount of wall or floor space, and are billed by HTP as “the original high efficiency low mass boiler produced in the United States.” Munchkin Honeywell series boilers were commercial boilers and carried the following model numbers: T50M, T80M, 80M, 140M, 199M and 399M.

The 399M model Munchkin boiler boasts a 93-percent AFUE rating. The unit is constructed of stainless steel, and is reportedly so lightweight it can be installed by one professional. The Munchkin boiler digitally monitors its own operation for efficiency purposes. Honeywell is an original equipment manufacturer for Munchkin boilers, producing such parts as gas valves and heating controls.

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Consumer Reviews of HTP Honeywell


  • Very Satisfied
  • Somewhat Satisfied
  • Neutral
  • Somewhat Unsatisfied
  • Very Unsatisfied
  • #6 of 12 HTP Boiler
  • 8% of customers recommended

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HTP Honeywell Boiler Reviews

Showing 11-15 of 25 reviews


3.0 rating

I was trained and taught to service Munchkin. I have a mastergasfitters license, master plumbers and master hvac. I even have a conversion burner gas license. I have found in over thirty years of service the simplest systems work best because simple people are more plentiful than complicated people and complicated stuff. Could it be that the majority of people refuse to invest in $1,500.00 analyzers and thousands of dollars of special instruments to actually do their jobs? Could it be they stop investing in education to stay current? I love the kiss method, but I have also found technology gives us more options. The trick is to embrace it and use it properly and hire people who know what to do. All products from the simple to the complex have problems. All maufacturers have had lemons in design and in units. But the first step is in the installer. Not all products can be applied everywhere. Choose wisely. Two, most installers barely have a high school education and it each day goes by they get more stupid as they do not train and educate. The consumer often gets the raw deal, because these people blame anybody, anything but themselves for the problems they face. When we blame the wrong thing we fail to work on the real problem. I can make a bad product look good or a good product look bad. What I can't do is get people to make better choices on who they hire because they are often too lazy to shop properly. You can't hire talent on low price and no background checking. If all you want is someone to light a wood log, you might just succeed with anybody, but in the area of combustion and today's technology that has been forced upon us with government standards and high cost of fuel and poor building designs, you have to hire experts. Without fail, every job I have gone on with a problem, had 3 issues. the part that failed, the thing that caused it to fail and lack of maintenance. I am not a fan of munchkin because it is complex and requires special training and tools, but don't most automobiles fit that same category? And I buy both. Heck, my whole industry now requires the equivalent of a college graduate to qualify for the work we have to do. If I have a choice I look for simple product that best fits my need and apply it properly. This alone eliminates 90% of service problems. Installation is the 100% most important part after the sale. It is here a 1/4" off level or a wire not tight, or some lack of knowledge, integrity and persistence to make it right ruins the project. And then even if it is perfect, we begin to use it and wear it out. Maintenance proper and complete at the full price required gives the consumer the best chance of having a good experience. If you can't afford the maintenance, you can't afford to own it. And yes even the best and simplest can be complicated by improper use of a thing. So I believe it when some people call this product junk and some call it great. I usually find the "junk" is a result of an incorrect choice, improperly applied, installed, used or serviced. It are these facts I have based and built my business on and why I call the plumbing heating and cooling fields recession proof. Good luck to all. Thanks to all who provide positive helpful comments. We all need to hear them all good and bad.

HL Bent


"Cross Your Fingers If You Bought One"

1.0 rating
Very Unsatisfied

I just got a $2000 repair bill for 2 circulators and a mother board. I have a oil burner in my other house for 20 years and the circulators are still running. Oh My God


Derry, NH

"My munchkin blows up!"

1.0 rating
Very Unsatisfied

Disastrous… Every so often my munchkin boiler emits a kaboom that will rattle a 3 story house and almost flip you out of your bed. Had all kinds of repairs and the problem persists. This is a dangerous product.

B Nordt


"Second new mother board in 3 years"

1.0 rating
Very Unsatisfied

On my Munchkin, I get f003 codes … two service technicians from two different companies came out last night at weekend rates. The second one was the outfit that installed this boiler 7 years ago. The technician tells me there's no message on the led display so he needs to order a "mother board" … this would be the second one (I replaced it in 2008 already). The first one cost $1,000 and took a week to get. The first technician reported an f003 error code .. thermistor problem … but he wasn't too savvy on this boiler so couldn't fix it. I had to find renters a hotel to stay in. This is a nightmare. I can't have an unreliable boiler with winter weekend renters. Any ideas?

vicki allison

Cape May NJ

"What a disaster"

1.0 rating
Very Unsatisfied

We have now had two of these pieces of junk and they have been a complete disaster. Both have had multiple problems but one common issue is the build up of combustion products (largely carbon) that accumulates and blocks the condensate drain leading to corrosion of the heat exchanger. The cost in servicing and replacement has been many times the money saved from lower gas bills compared to running the original 80 year old boiler. One thing I have learned from this experience is that the boiler must have a vertical self cleaning heat exchanger like those used in the Triangle Tube Prestige product.


Vancouver, Canada

Other Honeywell Reviews

A thread on details a discussion between HVAC professionals regarding Munchkin boilers. One installer comments that for the price and performance, he doesn’t understand why anyone would use any other boiler.

A homeowner writes to the experts on to ask about a loud noise that his Munchkin boiler makes when turned on; the unit was previously quiet in operation. After a technician´┐Żs house call, the owner reports that the burner gasket needed replacement, and the unit was again operating quietly. One expert commented that this was a common issue with “those boilers.”

A Munchkin owner asks the forum at for help in locating a qualified installer in rural Illinois. The expert installers suggest calling the company, or looking for someone qualified to install the Peerless Pinnacle, which they say is a similar boiler.

HTP Honeywell Model Numbers

The Honeywell is available in different models which vary in efficiency and capacity.

Model Number AFUE BTUs per Hour
140M 92 140000
199M 92 199000
80M 92 80000

Honeywell Warranty

Munchkin offers a 12-year warranty on the Honeywell series boilers. After the seventh year, the purchaser must pay a percentage of the replacement cost. Labor costs are not covered by the Munchkin warranty. The owner must contact the retailer and provide the original receipt for warranty issues.

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