Replacing Your Residential Boiler: Everything You Need to Know

Stack has installed and serviced steam and hot-water boilers in Northeast Ohio homes since 1976.

Here in Cleveland and across most of America, homes are typically heated in two ways: furnaces or boilers. Older boilers tend to be less efficient than furnaces – water must reach a higher temperature than standard water heaters – but there are newer, high-efficiency options available now. If you know you need to replace your unit or if you’re unsure of its condition, here is everything you need to know about replacing your residential boiler.

The Trouble with Boilers

If your boiler does need to be replaced, there will typically be signs first to alert you to any issues. Sometimes they’re a quick fix, but they could also be warning you of impending failure.

You’re getting no heat

If the problem isn’t with your thermostat, it’s going to reside with the heating element. You’ll want to check if the pilot light is lit – if it is, contact a professional for an inspection.

Leaking or dripping

If you notice water leaking from your residential boiler, do not attempt to repair it yourself. Always contact a professional to resolve the issue.

The cause will usually be from a broken or damaged internal piece such as a seal or valve. You could have a simple issue like high pressure. But there could be worn out components which need to be replaced.

Loud noises

Maybe you’ve begun to notice some unusual sounds emitting from your residential boiler. Air caught in the system commonly causes this, but there could be another source such as low pressure or kettling (a buildup on the heat exchanger which restricts flow and overheats the water, resulting in kettle-like noises).

Loss of pressure

If your central heating seems not to be running well, or the boiler continually shuts off, you could have an issue with low pressure. Check your pressure gauge for a level. Most residential hot-water boilers should read roughly 12–15 psi when cold. If yours reads well below that, call a professional.

Lack of heat from your radiators

There are several reasons your radiator may not produce heat, most of which are resolved quickly. If the bottom of the element is the only part conducting any heat, you may need to bleed it, which you can do yourself if you’re comfortable with it. If only specific radiators aren’t heating up, you may need to balance them, which generally just involves adjusting valves.

However, if neither of those things seems to be the solution, there most likely is an issue with sludge buildup in the boiler. The fix for that comprises of chemically cleaning or flushing the system which should only be performed by a professional.

Discoloration

Some discoloration such as black soot or yellow flames on the burner can mean your fuel isn’t burning correctly and must be repaired immediately. This can, in turn, mean a buildup of carbon monoxide. If this is the case with your boiler, check your CO detectors and contact a professional.

All of these problems will be relatively noticeable on a day-to-day basis, but there are a few signs that might not be as obvious without a little investigation.

Signs of Residential Boiler Failure

You don’t want to wait until your boiler fails before you consider replacing it. Here are four things you’ll want to review before your system breaks down:

1. How old is it?

There are a few different types of boilers floating around, and they each have a different lifespan. Condensing boilers, which are a little newer to the market, are a little harder to establish a timeline for, but they’re expected to last 15 years or more. Cast iron boilers are a little sturdier with a 20-30 year lifetime and can last even longer with proper care and maintenance. However, they’re much less efficient than condensing boilers, so while you may pay more upfront for a new unit, your efficiency savings help offset the cost over the life of the system.

2. What are your energy expenditures?

As a residential boiler ages, its efficiency drops, and your utility bills slowly rise. When they reach an unusually high point, there’s a strong chance your system has reached the end of its life.

3. How often does it need service calls?

Any piece of equipment is going to need maintenance and minor repairs from time to time. But if you have to make abnormally frequent calls to your contractor for problems, you may have reached a point where another repair is no longer the best long-term option. Stack can evaluate the system and help determine whether boiler repair or boiler replacement makes more sense based on its condition, age, and performance.

4. How comfortable is your home?

If you’ve noticed temperature variation throughout the day in your home – especially in different areas of the house – there’s a strong possibility your unit no longer has sufficient controls.

Choosing a New Residential Boiler

After a thought out analysis and evaluation of your current system, you’ve decided it’s time for a replacement system. How do you determine what is best for you?

What type of boiler do you want?

There are several different types of boilers on the market, so you’ll need to decide which one will work best in your home.

1. Steam boilers: These are not as common in homes today, but they do still exist. A heat exchanger boils the water and sends it through a system of pipes using pressure, and gravity brings cooled water back to the boiler.
2. Hot water boiler: Like the steam boiler, this type uses a heat exchanger. They differ in that they use pumps to distribute the heat through your home.
3. Natural gas boiler: Gas boilers are the most common type in Northeast Ohio homes. They burn natural gas from your utility line to heat water in the boiler’s heat exchanger. Modern gas boilers use electronic ignition instead of a standing pilot light, so they only burn fuel when your home calls for heat. In rural areas without gas service, many gas boilers can be set up to run on propane instead. Gas boilers still need electricity to run the ignition, controls, and circulator pumps, so they won’t produce heat during a power outage unless you have a backup generator.
4. Oil boiler: While water-based, these are still fueled by oil, so they are more common in rural areas for the same reason natural gas boilers are used there.
5. Condensing boiler: A condensing boiler captures heat that a standard boiler sends up the chimney. It cools the exhaust gases until the water vapor in them condenses, then uses that recovered heat to pre-warm the water returning to the boiler. That extra heat recovery lets condensing boilers reach 90% AFUE or higher, which lowers your heating bills. They vent through PVC pipe instead of a chimney and need a drain for the condensation they produce. They’re most efficient in systems with lower return water temperatures, like radiant floor heating.
6. Electric boiler: Electric boilers heat water with electric elements instead of burning fuel. They’re nearly 100% efficient at the unit, produce no combustion gases, and don’t need a chimney or vent, which usually makes installation simpler and less expensive. They also run more quietly than gas or oil models. The tradeoff is operating cost: electricity typically costs more than natural gas in Ohio, so an electric boiler usually costs more to run each month. Electric boilers are a practical fit for smaller homes, additions, or homes without gas service.

What about efficiency?

You always want to look at the AFUE (annual fuel utilization efficiency) rating of a new residential boiler. For a high-efficiency system, you’ll want to look for anything with an AFUE of 85 percent or higher. Non-condensing gas boilers typically rate around 80–87% AFUE. Condensing models reach 90–95% or higher. Electric boilers are nearly 100 percent efficient as they produce no waste gas.

What are your venting abilities?

Different types of boilers also have different venting requirements. If your home has a chimney, a chimney-vented boiler will easily pair with your ventilation system. Power-vent and direct-vent boilers need access to a roof or wall vent; if you don’t have a vent currently available, you’ll need to create one. The power-vented systems can only be placed in open rooms, as well, and condensing boilers have particular requirements.

Ready to Install a New Boiler? Talk to Stack’s Boiler Experts

Stack has been installing and servicing steam and hot-water boilers in Northeast Ohio homes since 1976. We’ll evaluate your current heating system, size a new boiler to your home, and explain your options so you can choose the right fit for your comfort and budget. When you’re ready, our licensed technicians handle the installation from start to finish.

Schedule a Boiler Consultation or call (440) 937-9134. Learn more about our boiler replacement services.

Frequently Asked Questions

Can I install a boiler myself?

Installing a boiler yourself isn’t recommended. Boiler installation involves gas piping, venting, and combustion testing, and a mistake can cause gas leaks or carbon monoxide exposure. Most Ohio communities require a permit and inspection, and many manufacturers won’t honor the warranty unless a licensed professional installs the unit.

How do I know what size boiler I need?

Hot-water boilers are sized with a heat loss calculation for your home. Steam boilers are sized by measuring the radiators connected to the system. Matching the old boiler’s size isn’t always correct, especially if the home has been insulated or renovated since it was installed.

How long does a residential boiler last?

It depends on the type and how well it’s maintained. Cast iron boilers often last 20–30 years, and condensing boilers are expected to last 15 years or more. Regular maintenance helps extend a boiler’s lifespan.

What are the signs I need a new boiler?

Common signs include an aging boiler, rising energy bills, frequent repair calls, uneven heating between rooms, leaks, and unusual noises. If your boiler shows several of these signs, have a professional evaluate whether repair or replacement makes more sense.