Yes, existing radiators can usually remain if they’re compatible, sized correctly, and in good condition. An installer should check the sludge, leaks, and pipework. Flushing and new valves may be chosen to protect performance and efficiency.

A new boiler can modestly improve air quality and reduce humidity only if it’s sealed-combustion and properly vented; otherwise, the effects are minimal. Better control prevents dampness, but real freedom comes from ventilation, dehumidification, and maintenance.

Yes, many governments offer grants, rebates, or low-interest financing for efficient heating upgrades, though eligibility varies by income, location, and system type. They should check national energy offices, local utilities, and approved-lender programs.

Common warning signs include CO alarms sounding, headaches, dizziness, nausea, confusion, fatigue, or breathlessness; pets acting ill; sooty stains, yellow flames, condensation, stale air, or pilot outages. Leaving immediately and contacting professionals protects independence.