Boiler Service & Repair

Boiler Repair, Maintenance, and Replacement for Wisconsin Homes

A significant share of older homes across southeast Wisconsin are heated by hot water boilers rather than forced air. From 1900s farmhouses to 1950s ranches to current-build luxury homes with in-floor radiant heat, boilers do their job quietly and efficiently for decades. Until something goes wrong. When it does, you want a plumber who actually understands hydronic systems, not a furnace shop guessing at it.

Doro Plumbing services boilers across the Hartford service area. Our Certified Master Plumber works on the plumbing side of the system: the boiler itself, the circulators, expansion tanks, zone valves, manifolds, baseboard, radiators, and the controls that make it all work together.

Types of Boilers We Service

Wisconsin homes have a wide range of boiler equipment installed over the years. We work on most of what we find:

• Cast iron sectional boilers, the workhorse of older homes, often 30+ years old and still going
• Modern high-efficiency condensing boilers using stainless steel heat exchangers
• Combi boilers that handle both heat and domestic hot water in one unit
• Cast iron and steel firetube boilers in larger homes
• Atmospheric and power-vented natural gas, propane, and oil units

If you are not sure what you have, we can take a look and tell you, including age, condition, and what we recommend going forward.

Common Boiler Repairs

The repairs we see most often:

• Failed circulator pumps and pump replacement
• Expansion tank replacement
• Zone valve repair and replacement
• Failed thermocouples, gas valves, and ignition modules on gas units
• Pressure relief valve replacement
• Air bleeds and bleeding individual zones that have lost pressure or trapped air
• Pressure-reducing valve replacement on the auto-fill water connection
• Backflow preventer service and replacement (Wisconsin code requires backflow on boiler fill lines)
• Glycol fill and concentration testing on systems with antifreeze
• Aquastat and control replacement
• Leaking sections, gaskets, and fittings

We carry common parts for most major boiler brands so we can usually finish a repair in a single visit.

Annual Service

Boilers reward regular service with long life and reliable operation. Annual service from us includes:

• Combustion analysis on gas units
• Cleaning and inspection of burners and heat exchanger
• Pressure check and adjustment
• Zone valve and circulator function tests
• Air bleed of any zones showing trapped air
• Glycol concentration test on systems with antifreeze
• Pressure relief valve test
• Visual inspection of vent piping, gas piping, and water connections
• Operational test through every zone

Skipping annual service is the most common reason older boilers fail prematurely. A small problem caught in October is much cheaper than a no-heat call in January.

Replacement and Installation

When a boiler is past saving, or you are converting to in-floor radiant heat or adding zones, we install new equipment correctly sized for the home. The sizing math matters more on boilers than on most appliances. An oversized boiler short-cycles, uses more fuel, and wears out faster than a properly sized one.

For new installations and replacements, we handle:

• Heat loss calculation to size the unit correctly
• Equipment selection based on your home, fuel availability, and goals
• Full piping including primary-secondary loops for high-efficiency units
• Circulator, manifold, and zone valve setup
• Controls, thermostats, and outdoor reset where appropriate
• Combustion air, venting, and gas piping per Wisconsin code
• Permits and inspections

In-Floor Radiant Heat

Boilers also drive in-floor radiant heat systems, which are increasingly common in basements, additions, and full new builds across this part of Wisconsin. We handle in-floor radiant work as a separate service. If you are considering adding radiant heat to an existing home or planning it for a new build, we are happy to talk through what makes sense.

Older Homes and Vintage Equipment

If you live in a Hartford foursquare, a Cedarburg century home, or a Waukesha bungalow, your boiler may be older than your grandparents. Cast iron boilers are remarkably durable and many of these older units run perfectly fine with regular service. We will not pressure you to replace something that is working. When the time eventually comes, we can plan a replacement that fits your home’s specific situation.

Doro Plumbing · (262) 229-5632 · Hartford, WI