If your only goal is hot water for faucets and showers, a tankless water heater is a direct answer. If you already have a hydronic boiler for heat, you may be able to make domestic hot water from it, which can mean you do not need a separate heater at all. The right choice depends on what already runs in your house.
This guide covers domestic hot water only. Boiler repair, replacement and heating system design beyond hot water are outside what this site covers. For hot water questions, call (860) 397-8103 and describe what you have now.
Side by side: what each option does
A quick comparison of the common ways to make hot water. Details change with the brand and your home.
| Option | Heats your home | Hot water source | Best fit |
|---|---|---|---|
| Tankless water heater | No | Heats water as it flows | Home with separate heating, wants endless hot water |
| Boiler with indirect tank | Yes | Boiler heats a separate insulated tank | Home with an existing boiler and steady hot water demand |
| Combi boiler | Yes | One unit heats home and makes on-demand hot water | Smaller homes, limited space, modest simultaneous use |
| Boiler with tankless coil | Yes | Coil inside the boiler heats water | Older systems, often less efficient in summer |
| Stand-alone tank heater | No | Stored water heated by gas or electric | Simple, lower cost, any heating type |
How each approach works
A tankless water heater has no storage. When you open a hot tap, flow triggers a burner or heating element that warms the water as it passes through. You get hot water as long as the unit can keep up with the flow.
A boiler heats water for a hydronic system with radiators or baseboard. Some boilers can also make domestic hot water. How they do it is the part that matters for your choice.
Indirect tank
An indirect tank is a well-insulated storage tank that gets heat from the boiler through an internal coil. It has no burner or element of its own. It keeps hot water ready, holds temperature well and is often more efficient than a tankless coil in a boiler.
Combi boiler
A combi boiler combines heating and on-demand hot water in one wall-mounted unit. It saves space and removes the separate heater. Hot water output is limited by the unit, so a household running two showers and a washer at once may find it tight.
Tankless coil
Some older boilers have a coil inside that heats domestic water. It makes hot water without a tank, but the boiler must stay hot to supply it, which wastes fuel in warm months. Many homeowners replace this setup when it wears out.
Questions to ask before you decide
- What do I already have: a boiler, a furnace with ducts, or electric heat?
- How old is the boiler, and does it have a tankless coil or an indirect tank?
- How many people and fixtures use hot water at the same time?
- Can the gas line, venting and electrical supply handle the new unit?
- What is the full installed scope, including venting, drains and removal?
- Who services the unit afterward, and how often does it need flushing?
- Should I replace only the hot water side, or is the boiler near the end of its life?
What this site does and does not cover
We handle domestic hot water: tank heaters, tankless heaters and the plumbing that connects them. Boiler work beyond domestic hot water, including heating zones, radiators and boiler replacement, is outside what this site covers. A heating contractor is the right call for that.
When tankless is the better pick
Tankless fits when your heat comes from a furnace or electric baseboard, so there is no boiler to lean on. It also fits if you want endless hot water, have a bigger family and want to free floor space. See our tankless water heater service page for the work involved.
Watch the installed cost. Gas models may need a larger gas line and new venting, and electric models can need a heavy circuit. Our guide on water heater installation covers what a planned install includes.
When a boiler setup is the better pick
If you have a working hydronic boiler in good shape, an indirect tank is often a sensible way to make domestic hot water. It uses a heat source you already own and gives steady supply. It is a dependable setup for homes that already run on baseboard or radiators.
If the boiler is old and likely due for replacement, it may be worth replacing the whole system at once. That decision belongs with a heating contractor, and a plumber can then connect the hot water side.
Rocky Hill housing and hot water choices
Most Rocky Hill housing dates from 1960 to 1990, and about 39 percent of units were multi-family in 2010. Homes of that age often have an existing heating plant with its own hot water arrangement, so the first step is finding out what you have. In multi-family buildings, shared systems may limit what you can change.
This means check before you shop. Look at the data plate on your boiler or heater, and ask your landlord or association if the equipment is shared.
Source type: town planning document and census counts
Common mistakes
- Buying a tankless heater without checking whether your boiler could already supply hot water.
- Choosing a combi boiler for a large household with several simultaneous showers.
- Keeping a tankless coil boiler running all summer just for hot water.
- Ignoring venting and gas supply until install day.
- Assuming a boiler plumber and a water heater plumber are always the same visit.
Talk it through
We help with the domestic hot water side across Rocky Hill and nearby towns, including Wethersfield and Cromwell. Plumbers follow model codes such as the International Plumbing Code (IPC), and Connecticut's state building code is based on the 2021 International Codes. Ask the building department what applies to your switch. Call (860) 397-8103 and tell us what is installed today.
Questions homeowners ask
Is a tankless water heater better than a boiler?
They do different jobs. A tankless unit only heats water for your taps. A boiler heats a hydronic system and can also supply hot water through an indirect tank or combi design. If you already own a good boiler, adding a separate tankless unit may not be needed.
What is an indirect water heater?
It is an insulated storage tank with an internal coil. Hot water from your boiler runs through the coil and heats the stored water. It has no burner of its own, so it relies on the boiler running.
Can a combi boiler replace my water heater?
Often yes, because it heats your home and makes hot water on demand. Output is limited, so large households with several showers at once may find it too slow. Ask a contractor to size it.
Do you work on boilers?
Boiler work beyond domestic hot water is outside what this site covers. We handle tank and tankless water heaters and the plumbing around them. For heating zones, radiators or boiler replacement, a heating contractor is the right call.
What should I ask before swapping my hot water setup?
Ask what you have now, how old it is, what the full installed scope includes and who services it afterward. Also ask whether gas line, venting or electrical changes are needed.
Do you serve homes near Rocky Hill?
Yes. We serve Rocky Hill and nearby towns, including Wethersfield, Newington and Cromwell. Call (860) 397-8103 and we confirm availability for your address.
Call the 24/7 line, describe the problem, and we confirm what it will cost before any work starts.