Boiler vs. Furnace: What Philadelphia Rowhome Owners Should Know

Short answer: boilers heat water and send it to radiators or baseboards; furnaces heat air and blow it through ducts. Philadelphia's older rowhomes were often built around radiator heat, so many still run boilers — and if your house has no ductwork, sticking with a boiler (or adding a ductless system) is usually smarter than paying to duct a rowhome. If you already have ducts, a furnace typically wins on cost and adds the option of central AC.

How they differ day to day

• Boiler heat feels steady. Radiators warm rooms evenly and quietly, without blowing air — a big reason old-house owners love them. No ducts also means no duct dust.
• Furnace heat is fast and flexible. Ducted air warms the house quickly, and the same ductwork carries central air conditioning in summer — one system of ducts, two jobs.
• Maintenance differs. Boilers have fewer moving parts and long service lives; furnaces need filter changes and share their ducts with your cooling.

The rowhome reality

Much of Philadelphia's housing predates ductwork. Retrofitting supply and return ducts into a 16-foot-wide rowhome means sacrificing closet space and opening walls — doable, but the cost changes the math. Common paths we see:

• Radiators you like + boiler dying: replace the boiler. Modern 94%+ AFUE units are far more efficient than what they replace.
• No ducts + want AC too: keep the boiler for heat and add ductless mini-splits for cooling — or let mini-split heat pumps handle both.
• Ducts already exist: a furnace replacement is straightforward — and pairing it with AC in one project saves on labor (see our real package pricing).

What replacement costs

A new gas furnace installed by Lumen runs $2,000–$4,000; a complete furnace + AC setup runs $6,500–$8,500 — full numbers on the pricing page and in our furnace cost guide. Boiler pricing depends heavily on the system type — call for a real quote.

Philadelphia rebates apply to both

PGW's EnergySense program currently pays $400 on 95%+ AFUE furnaces, $1,000 on 94%+ AFUE boilers, and $1,400 on combi boilers (which handle heat and hot water in one unit) — income-qualified households get up to double. Details on our rebates page; we file the paperwork on every qualifying install.

Get an answer for your specific house

The right call depends on your ducts, your radiators, and how long you're staying. Lumen installs and repairs furnaces, boilers, and complete systems across Philadelphia — and if the honest answer is "repair, don't replace," that's what we'll tell you. Call (267) 252-2969 for a free replacement estimate.