• Up to 95% AFUE, ENERGY STAR® Certified
  • AI Control Technology, Auto Commissioning and Continuous Calibration functions optimize combustion and result in lower fuel costs. Control Panel features a backlit digital display that indicates boiler status, temperature and diagnostics.
  • 75 MBH – 164 MBH
  • 4.5:1 Turndown Modulation Ratio in Heating Mode (MAH-75)
  • 5.6:1 Turndown Modulation Ratio in Heating Mode (MAH-100)
  • 5.7:1 Turndown Modulation Ratio in Heating Mode (MAH-125)
  • 5.5:1 Turndown Modulation Ratio in Heating Mode (MAH-165)
  • Primary/Secondary LABOR SAVER™ Manifold Included
  • Heat Exchanger: 316L Stainless Steel Heat Exchanger and Burner.
  • Additional Features: Assembled Boiler With Jacket, Induced Draft Fan, High limit sensors, 30psi Relief Valve, Low Water Pressure Switch and, Temperature/Pressure Gauge.
  • Build-In Load Matching Pump contributes to savings in electrical usage.

  • Outdoor Temperature Sensor, Indirect Tank Sensor and, Floor Stand Kit
  • Our AI control technology is programmed to recognize an Indirect Tank. H2O Indirect Hot Water Heaters are available in 30 to 115 gallon capacities and feature 316L stainless steel construction and top connections for an easy installation.

See Installation, Operation and Maintenance Manual for complete instructions

Boiler Manuals
MAC/MAH Boiler Manuals Rev. A
MAC/MAH Boiler Manuals, Rev B
MAC/MAH Boiler Manuals, Rev C
MAC/MAH Boiler Manual Rev. F
MAC/MAH Boiler Manual Rev. G
MAC/MAH Boiler Manual 115-205 Rev. A
MAC/MAH Boiler Manual 100-205 Rev. A
MAC/MAH IOM Rev. A – French
MAC/MAH Boiler Manuals Rev. B
Brochure
MAC/MAH Sell Sheet Rev. 10-20-22
MAC/MAH Sell Sheet Rev. 03-08-22
MAC Brochure, Rev. 4/16
MAC Brochure, Rev. 6/16
MAC Brochure, Rev. 7/16
MAC Brochure, Rev. 1/17
MAC Brochure, Rev. 8/16
MAC Brochure, Rev. 9/17
MAC Brochure, Rev. 1/18
MAC/MAH Brochure, Rev. 2/2019
Engineering Documents/Resources
Artificially Intelligent, Condensing Boiler Application Guide, Rev. 5/16
MAH-125 Spec Sheet Rev. A
MAC-150 Spec Sheet Rev. A
MAH-125 Submittal Rev. A
MAC-150 Submittal Rev. A
Condensing Boiler Application Guide, Rev. 9/16
MAC/MAH Condensing Boiler Application Guide, Rev. E
AI Boilers 115-205 Application Guide Rev. N
Wall Hung AI Boiler Application Guide Rev. P
Installation & Operation Manual
MAC Installation & Operation Manual, Rev. 4/16
MAC Installation & Operation Manual, Rev D
MAC Installation & Operation Manual, Rev E
MAC/MAH Installation & Operation Manual, Rev F
MAC/MAH IOM Rev D
Parts Lists
MAC/MAH Parts List 75-205 Rev. B – French
MAC/MAH Parts List 75-205 Rev. B
MAC/MAH Parts List 75-205 Rev. A
MAC/MAH Parts List 75-205 Rev. A – French
MAC/MAH Parts List, Rev. C
MAC/MAH Parts List French, Rev. C
MAC Parts List, Rev. 5/16
MAC Parts List, Rev. 5/3/16
MAC Parts List, Rev. E
MAC Parts List, Rev. G
Specification/Performance
MAH-125 Spec Sheet Rev. B
MAC-150 Spec Sheet Rev. B
MAC-205 Spec Sheet
MAH-125 Spec Sheet Rev. C
MAC-150 Spec Sheet Rev. C
MAC-205 Spec Sheet Rev. B
MAH-165 Spec Sheet Rev. A
MAH-165 Spec Sheet Rev. C
MAC-205 Spec Sheet Rev. C
MAC-115 Spec Sheet Rev. A
Submittal
MAH-75 Submittal Rev. A
MAH-125 Submittal Rev. B
MAC-150 Submittal Rev. B
MAC-205 Submittal
MAH-125 Submittal Rev. C
MAC-150 Submittal Rev. C
MAH-165 Submittal Rev A
MAH-165 Submittal Rev. C
MAC-205 Submittal Rev. C
MAC-115 Submittal Rev. A
User Manual
MAC/MAH User Manual, Rev. A
MAC/MAH User Manual French, Rev. A
AI Boilers 115-205 User Manual Rev. A
MAC/MAH/MACF/MAHF User Manual Rev. B
MAC/MAH User Manual Rev. A – French
Wall Hung AI Boiler User Manual Rev. A
Warranty
MAC Condensing Boiler Warranty, Rev. 4/16
MAC Condensing Boiler Warranty, Rev B
MAC Condensing Boiler Warranty, Rev C
MAC/MAH Condensing Boiler Warranty, Rev D

product-586

Looks good, runs good. Having some issues with the hot water not mixing properly all the time. Install company not sure what is causing it.

Tim
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Nice compact unit. Longer horizontal combi venting runs are difficult.

Roy
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Easy install customer support was fast and easy

Ray
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Very efficient and fairly easy to install. Had no issues upon startup

Bob
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Every contractor I talked to said this is the best boiler they have installed!

John
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

I’ll recommend it to my customers. It’s made nice. Easy to work on it.

Zigzag Industrial
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Yes, great space saver and love the unlimited hot water.

Homeowner
Product Reviewed:
Condensing Gas Boiler - MAC/MAH
product-586

Great product. Very quiet and reliable. Good tech support.

Charles Arnett
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

It’s super compact. The unit is so quiet but my only concern was the water run off, but I muffled that.

Scott Strother
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Ease of installation and performance would be the two main features I would share. I also like the quiet operation of the unit. I live in CT, and installation occurred on this winters coldest day. The water inlet temperature is very cold this time of year, and but the on demand DHW comes on pretty quickly and fills a tub super hot.

Seweryn Borecki
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Very clean, doesn’t take up much room and works great!

Nicole Talaia
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

This boiler installed very quickly and easy.

Chris Ghosio
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

I would recommend it and have. It is so nice to have on demand hot water and there is no noise.

Patricia Gardner
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Great boiler very efficient and definitely quiet. Easy to install.

Ty Kovalewski
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

The overall dimenseions, efficiency, and ease of use is great. After speaking to many installers/ HVAC technicians, Utica was the most frequently suggested brand to purchase. Low maintenance, quality of construction, and high quality components were the main reasons for the recommendations.

Jason Matthews
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Yes I would recommend this product because it is small, compact, quiet and easy to install.

Charlie Cashin
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Yes I would recomment this product. Unit is very quiet, east to install, and a great value compared to other brands.

Red Riehle
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

I would recomment this product. The product is very efficient and works great.

I would strongly recommend this product to anyone in need of replacing existing boiler/water heater or just upgrading for efficiency purposes.

Jorge Morales
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Works well.

On the Mac 150 if they had the hot and cold inlets off set from the boiler inlet and out let it would ease the install, now they are all inline.

Gary Adams
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Yes I would recomment this product to a friend. Dependable, easy to install, and helpful tech support.

Edward Hosmer
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Saving money and energy with your product.

Spring brook fuel and ice should NOT be installing your product no license and don’t know what they are doing. Without your rep my unit would not be working.

Homeowner
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

This was an easy installation and is a good boiler for larger homes.

I had a hard time with the venting of this boiler. The supply house didn’t have a good knowledge of this product. I was told I could vent it with 2″ pipe. After talking to the factory service and engineering department I was still unsure of how to vent it. Help finaly came when I talked to Howard Dyson and Gary Alex. I ended up venting the boiler with 2″ cpvc on the exhaust side and pvc on the intake.

Homeowner
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

I highly recommend Utica Boilers. Built in USA. Rep for company is very helpful

Scott
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

The 40 year old boiler we had never gave us a problem but replaced to be more efficient

James
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High
product-586

Easy installation and user friendly

Paul
Product Reviewed:
Condensing Gas Boiler - MAC/MAH High