Boiler repair vs replacement in NJ: why yours probably doesn't need replacing yet

How long a boiler actually lasts

The part of a boiler that does the work is the heat exchanger: the cast-iron sections or steel vessel where the burner's heat passes into the water. A well-maintained cast-iron boiler commonly runs for twenty-five or thirty years, and plenty of North Jersey basements still have older ones working well.

Everything else on the boiler, the burner, the controls, the pump, the valves and the safety devices, is a component. Components wear out on their own schedule, and replacing one does not mean the boiler is failing. A twenty-year-old boiler with a new igniter is not a twenty-year-old boiler that is about to die.

The parts that fail, and why they don't mean a new boiler

These are the repairs we make most often on boilers that other people had written off. Each one is measured in hours, not days.

• Ignition parts: the thermocouple, flame sensor, igniter or pilot assembly. When these fail the boiler will not light or will not stay lit, which looks like a dead boiler but is usually a small part.
• The circulator pump on a hot-water system. If the boiler is hot but the radiators are not, the pump that moves the water may have failed.
• The expansion tank. When it loses its air charge, pressure climbs as the water heats and the relief valve starts to drip or discharge.
• Zone valves and thermostats. One cold zone in an otherwise warm house is almost always a zone valve, a thermostat or its wiring.
• On steam systems, the low-water cut-off and the pressure control. Both are safety devices, and both can stop the boiler when they need cleaning or replacing.
• The gas valve and the control board. More expensive than the parts above, but still a small fraction of a new boiler.

A plumber who recommends replacement because of any of these has not given you a reason to replace the boiler.

When replacement really is the right call

There are genuine reasons to replace a boiler, and an honest plumber will tell you plainly when you have one.

• A leaking heat exchanger. Water or steam escaping from the body of the boiler itself, rather than from a fitting or valve, means a cracked section. On steam boilers, needing to add water far more often than before can be the first sign, though an automatic water feeder can hide it.
• Combustion problems traced to the heat exchanger. Soot, flame roll-out or carbon monoxide caused by a damaged heat exchanger are not repairs; that boiler should be shut down and replaced.
• Parts no longer made. Some older boilers use controls or burners that are no longer manufactured. If a critical part cannot be had, the economics change.
• Repeated major failures. One repair is maintenance. A new major failure every winter is a pattern worth pricing against a replacement.

A rule of thumb many in the trade use: if the repair costs more than half the price of a replacement, and the boiler is already old, replacement deserves a serious look. Below that, repair almost always wins.

The efficiency argument, honestly

Newer boilers are more efficient. ENERGY STAR certified gas boilers are rated at 90% AFUE or higher, and oil boilers at 87% or higher, while many older boilers run well below that. Over years of fuel bills, that difference is real money.

But it rarely pays for a new boiler on its own, especially when the old one only needs a part. And for steam heat the gap is smaller than the sales pitch suggests. High-efficiency condensing boilers only work on hot-water systems. A steam system needs a steam boiler, and those cannot condense, so the efficiency gain from replacing a working steam boiler is modest.

Steam boilers are a special case

Many homes in Essex, Hudson and the older parts of Bergen still heat with steam. Replacing a steam boiler well is specialist work, and getting it wrong is behind a lot of noisy, uneven heat.

• A steam boiler has to be sized to the radiators actually connected to it, not to the square footage of the house. An oversized boiler short-cycles and wastes fuel.
• The piping right next to the boiler has to follow the manufacturer's instructions. Shortcuts here send water up into the system with the steam, which causes banging and wet, inefficient heat.
• A new steam boiler has to be skimmed to remove oil left from manufacturing. Skip it, and the water level surges and the boiler struggles for months.

If your steam boiler is working, keeping it running is very often the better decision.

Questions to ask before you agree to a new boiler

• What exactly has failed? Can you show me?
• Is the problem in the heat exchanger, or in a part attached to the boiler?
• What would repairing that part cost, including labour?
• If I replace the boiler, how was the new one sized?
• Is the price for the boiler alone, or does it include the near-boiler piping, the permit, the inspection and removing the old unit?

If the answers are vague, get a second opinion. A good plumber will not mind you asking.

Permits and inspection in New Jersey

Replacing a boiler in New Jersey needs a permit and an inspection through your town's construction office. The contractor doing the work should pull the permit, and it should be in the price. Repairs and part replacements generally do not need one. Ask any installer who quotes for a new boiler whether the permit is included.

How we approach it

We diagnose the whole system before recommending anything, we show you the part that has failed, and we give you the price before any work starts. If your boiler genuinely needs replacing, we will tell you why and size the new one properly. If it needs a part, that is what we will fix.