A boiler heats water for a home’s hydronic heating system. Some arrangements also provide domestic hot water, while others use a separate water heater. The pipework and controls in the home determine what a replacement needs to support.
Understand the existing setup
Ask whether the boiler feeds radiators, in-floor tubing or another heating circuit. Identify any separate hot-water tank and note the space available for new equipment. A combination, or “combi,” unit serves heating and domestic hot water in one appliance, but suitability depends on demand and installation details.
Efficiency figures are useful only when comparing appropriate models under their stated conditions. Venting, fuel supply and controls can change the scope and cost.
Plan the replacement
Photograph the rating label and note any rooms that heat poorly. Our boiler and heating team can review the current system and explain suitable service or replacement options.
Separate space heat from tap water
Some homes use a boiler only to circulate hot water through radiators or in-floor loops. Others also rely on it, directly or through another component, for domestic hot water. That distinction matters when comparing a combination unit with a boiler plus separate water heater. Ask the installer to show which existing pipes and controls serve each purpose and how the proposed replacement will meet both demands.
If only one heating zone is cold, the problem may be in its controls or distribution rather than the heat source. Record which rooms are affected before assuming the boiler needs replacing. For a planned bathroom or whole-home project, our in-floor heating guide explains another part of the system to consider.