HTP Munchkin R1 Boilers | "Revision 1" Boiler | FurnaceCompare®

HTP Munchkin R1 Boiler Overview

Manufactured by Heat Transfer Products Inc. (HTP), the Munchkin R1 is a residential ultra-efficiency boiler offering up to 95.1 percent AFUE. This Energy Star-certified series has five models ranging in heating capacities from 50,000 to 199,000 BTUs.

Available as a wall- or floor-mounted unit, the R1 has a lightweight design geared toward providing easy installation, as well as zero clearance to combustibles. The R1 also offers four different venting options–vertical, unbalanced, sidewall and concentric–for flexible installation and airflow.

Indirect water heater integration, a durable 316L stainless steel heat exchanger and an outdoor reset that detects temperature changes outside and adjusts the interior temperature accordingly are additional features of this unit.

The Munchkin R1 series is a revised version of the HTP Munchkin boiler series.

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Consumer Reviews of HTP Munchkin R1


  • Very Satisfied
  • Somewhat Satisfied
  • Neutral
  • Somewhat Unsatisfied
  • Very Unsatisfied
  • #3 of 12 HTP Boiler
  • 30% of customers recommended

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HTP Munchkin R1 Boiler Reviews

Showing 6-10 of 70 reviews

"Love it."

5.0 rating
Very Satisfied

Bought this one new on the net for $1800 10 years ago. Plumber had planned on installing 6 on a project and only used 5. I was the high bidder around Christmas time. Never installed any boiler ever before. Read the instructions many times. Installed with new in floor oxygen barrier pex. After 10 years, crystal clear water with pH of 8.5. Primary secondary piping with a Grundfos 15-58 on 2 in the primary and a Bell and Gossett 100 on low head secondary. Widely spaced intake and exhaust. Virtually maintenance free. Runs at low water temperature which I think helps. I got scared looking at all the troubles on the net so I bought a used one as a spare so I don't have to change any plumbing. If I had it to do over I would have plumbed in a dirt filter (hasn't needed it) and a spirovent instead of an air scoop. Propane bills are minimal. Sorry to hear of the troubles. I think I got a good one and I think the install went well. Spared no expense on the install, combination of 1 1/4 black pipe and 1 1/4 manifolds. The heat radiation from the secondary manifolds (long, by design) takes the chill off my basement shop. One way or another I am heating 2300 sq ft times 2 on this boiler. Very quiet, very efficient, very inexpensive. (Having just said that just about will guarantee complete explosion of the whole thing tonight).


Scranton, PA

"Do not buy!"

1.0 rating
Very Unsatisfied

As much money as you save on energy costs with this unit, with the money you spend on maintenance and repairs you can buy a new one every 3 years almost. I live in a small condo building with 12 units and all have a Munchkin and all have problems. The service guy is out so much he has a key to our building and keys to most of the residents' units. If you only have him out 2-3 times a year consider yourself lucky. Each visit seems like at least $300-$500. They are so unreliable. Like someone said, if you go on vacation or away for a while in the winter you worry and have to have a friend come over just to make sure the thing is running. It's working perfectly fine and then all of a sudden there's no hot water or no heat and you go look and of course there is some error code. You pray that a simple reset will do the trick and you will not be at the mercy of your repairman in the dead of winter. They are very efficient, however. I have a 1,400 square foot condo and my gas bill is rarely over $60 during the winter. I forgot to mention and wonder if anyone else has had this problem. A few weeks ago I heard this loud boom and thought someone had hit our building. Looked outside and saw nothing. I was next to the room where my Munchkin is. I'm thinking surely it wasn't from there. Opened the door just to check and everything was fine. Well, like 5 days later there was another loud boom and it definitely came from the boiler room. It was so loud my ears felt like they were going to pop and my dog kept barking for an hour. I opened the door and didn't see or smell any gas. There are 2 expansion tanks to the system so I thought it was probably from them. I had my HVAC guy come out the next day. I wasn't home. He has a key to my place since he's out so much, but he tightened some valve where gas was in fact leaking and he said I guess they are having problems with a lot of them doing that! I'm at the point where I'm looking into getting a new system. I think it is pathetic that a company would put out a product that has so many issues and that someone would consider replacing after only 8 years.

J. Griffon

Cleveland, OH

"When installed properly they are great"

5.0 rating
Very Satisfied

Gotta love all the hatred on this site. Just shows how many sub-par installers there are around the country. I have installed many HTP boilers. The t-80m and t-500 might not be my favorite to service due to the cramped boiler enclosure but I have not had any that I installed fail. However I have replaced quite a few installed by other contractors. Installs that made me scratch my head. When these high efficiency boilers (any brand) are installed haphazardly they will fail. The Munchkin boilers were among the first high efficiency boilers on the market. Being the first means contractors had no idea how to install them properly since they know what they are doing, after all they had been installing boilers for years, who needs to get training to install a simple boiler. So they would install them like the ancient cast iron or copper tube boilers they had been installing for the past 100 years. There is the problem…these especially are not your grandfather's boilers, they need to be installed how they were intended to be installed. There is no inherent flaw in these boilers. No reason or case for a class action lawsuit against HTP. If you want to go legal on someone, go after the contractor who installed your boiler. Every product has its issues, I'm not trying to say these are perfect, they definitely have their quirks, but no fatal flaws. When they are installed in the proper manner, when they and the entire system is properly maintained by the homeowner (calling a knowledgeable(that is the important word) authorized repair technician) servicing and calibrating the boiler and system yearly, the boiler will last quite a long time. But if you don't it will fail prematurely and you can't blame that on the manufacturer. If you don't change your new Mustang's oil and the engine dies do you blame Ford for making a crappy product that stopped working? It is sad that so many people have a hard time finding someone competent to work on their Munchkin. I would be more than happy to work on any HTP boiler in the country. The travel charge might be pretty high, but what fun it would be. Stop the Munchkin hate.

Justin smith

Palo Alto, CA

"10 years strong"

5.0 rating
Very Satisfied

Here is how to keep these boilers running forever: Proper install: Keep exhaust away from intake (critical). Make sure exhaust gas is analyzed and adjusted on the money. Maintain: Clean "coffee grounds" out every other year (use old credit card or feeler gauge to get between the fins), flush out with water, and use a wet vac to pull water from the condensate drain. Clean the igniter and flame sensor with a green pad and use compressed air to clear off dust (keep control board clean). To make service easier, I added quick release clamps and gaskets on the lid, added flexible gas pipe before Dungs (I noticed they now do this with Elite FT boilers). These will pay for themselves if maintained. We service our cars regularly, why not our boilers.

S. Archer

Newton, MA

"In line damper"

4.0 rating
Somewhat Satisfied

One comment was made that a Fernco in-line damper was installed to combat downdraft problems. My question is "Where on the system should the damper be installed?". Thanks!

j. wanchisn

Richmond, VA

Other Munchkin R1 (Revision 1) Reviews

Most of the reviews around the web pertaining to the Munchkin R1 revolve around troubleshooting issues. Web forums such as and reflect a wide array of complications homeowners have had with this unit. Ignition failure, water discharge, blower motor replacement and failing components are among the issues posted.

In addition, contractors on note that Munchkin units have had problems in the past with specific components, such as inducers and swirl plates. In order to prevent unexpected repairs or component failure, these contractors advise consumers to ensure their units receive yearly maintenance.

HTP Munchkin R1 (Revision 1) Model Numbers

The Munchkin R1 (Revision 1) 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

Munchkin R1 (Revision 1) Warranty

HTP provides a 3-year warranty for the R1 blower motor and a complete 1-year warranty for any defective parts. Within two to seven years after installation, HTP will replace or repair any part that is defective due to a leaking heat exchanger.

During the eighth through twelfth year of use, HTP will cover only a certain percentage of the cost to repair or replace the defective boiler. The percentage paid varies depending on the age of the unit.

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