Is heat loss or the heating system the main problem? | Homecode

What is known — and what is not

Why this is not a binary choice

A home can lose heat quickly while the heating also delivers heat unevenly or responds incorrectly. Bills add tariff, readings, hot water, occupancy and weather, so a single observation should not be used to sell a boiler, radiator or insulation measure. [1][4][6]

Build a non-invasive evidence pack

• Record each room's setpoint, air temperature, visible demand, time to warm and whether target is reached during normal use. [1]
• Record external thermostat, zone and boiler status plus room-by-room radiator response without touching hot surfaces or opening equipment. [1][3]
• Note ordinary room cooling after a scheduled period without deliberately under-heating anyone or blocking ventilation.
• Compare actual gas kWh with weather, occupancy, setpoint and hot-water context, and gather the current EPC and existing work records. [4][6]

When to stop

This review covers only the stated non-emergency observations. Stop if a fault or safety warning appears, equipment is damaged, wet, leaking or abnormally hot, or the check cannot stay on a normal room floor without opening, detaching, resetting or adjusting anything outside documented occupant controls; the new fact needs its own H3 route. [1]

Who to contact next

• Use the energy supplier first where billed kWh, readings or account data are unreliable. [5]
• Use a correctly qualified Gas Safe registered engineer where boiler, combustion, flue or integrated-control behaviour is abnormal, with a competent heating engineer for water-side heat delivery. [2][3]
• Use an independent retrofit assessor, domestic energy assessor or building surveyor for construction-specific heat loss, moisture, ventilation and measure suitability. [6]

Cost and quote evidence

Ask heating quotes for measured faults, controls and heat delivery, and fabric quotes for construction, condition, ventilation, moisture and thermal-bridge assumptions. Keep capital cost separate from uncertain kWh savings and reject a guaranteed bill, payback or value claim. [4][6]

Effect on a sale or letting

Unresolved cold and high-use concerns may prompt survey, buyer or tenant questions, but they do not prove a defect or quantify value. Keep the EPC, room evidence, Gas Safe report, independent fabric assessment, invoices and certificates; covered private rented homes in England and Wales generally need EPC E or a valid exemption, while live heating faults still require separate attention. [6][7][8]

If you smell gas or a carbon monoxide alarm sounds

• If you smell gas or suspect a leak, stop this page. HSE says to call 0800 111 999 immediately, open all the doors and windows, and shut off the gas supply at the meter control valve if you know where it is. [2]
• National Gas says not to smoke or light matches, and not to turn electrical switches on or off. Do not enter a cellar to reach a meter. The National Gas Emergency Service on 0800 111 999 is free and open 24 hours a day in Great Britain. [9]
• If a carbon monoxide alarm sounds or you suspect carbon monoxide, NHS says to stop using the suspected appliance if you can, go outside, and get medical advice before going back in. Call NHS 111 if you have symptoms. Call 999 if anyone is finding it hard to breathe, has suddenly become confused, has lost consciousness, feels weak, or has chest or muscle pain. [10]
• If you think a gas appliance is leaking carbon monoxide, NHS says to call the National Gas Helpline on 0800 111 999. That number is for Great Britain. HSENI publishes 0800 002 001 for the Northern Ireland Gas Emergency Service. [10][11]
• Do not restart or work on a gas appliance, flue or pipework. HSE says anyone employed to work on gas appliances in domestic premises must be a Gas Safe registered engineer. [2]