Boiler Not Heating? Complete No‑Heat Troubleshooting Guide for Lower Mainland Homes

If your boiler is not heating and your home is getting cold, you need clear steps fast. Boilers are safe and efficient when they work properly, but when there’s no heat, it can be hard to tell what’s a simple fix and what’s a serious problem. This guide walks through the most common “boiler no heat” scenarios, what you can safely check yourself, and when to stop DIY and call a licensed technician.

Budget Heating & Plumbing is a Lower Mainland–based plumbing and heating contractor providing boiler installation, repair, and maintenance in North Vancouver, West Vancouver, Vancouver, Burnaby, New Westminster, Coquitlam, Port Coquitlam, Port Moody, Surrey, Langley, Abbotsford, Chilliwack, and surrounding areas. If your boiler has stopped heating or you’re not sure it’s safe to run, call 604-343-1985 for professional help.

Boiler Not Heating Anywhere in the House

When the entire house is cold and none of the radiators or in‑floor zones are heating, your boiler or its controls may have shut down.

What you can safely check:

• Thermostat settings: Make sure the thermostat is set to HEAT, above room temperature, and that any schedule or “vacation” mode is not holding it off.

• Power: Confirm the boiler’s power switch (often near the unit) is ON and check your electrical panel for a tripped breaker.

• Gas supply: If you can see the gas valve and feel confident, confirm it is open; if you smell gas, do not relight anything—leave the house and call for help.

Stop and call 604-343-1985 if:

• The boiler repeatedly tries to start and shuts off.

• You see error codes or flashing lights and don’t know what they mean.

• You smell gas, burning, or see scorch marks or water around the boiler.

Boiler Working But No Heat in One Room or One Zone

If most of the home is warm but one room or one area is cold, the problem is usually local to that zone, not the whole boiler.

What you can check:

• Thermostat or zone control: Make sure the thermostat for the cold area is turned up and set to HEAT, and that it has working batteries if it uses them.

• Radiator or in‑floor valves: Check that valves serving the cold radiator or zone are open and not accidentally turned off.

• Air in radiators: If you know how to safely bleed a radiator and have the right key, you can carefully release trapped air; stop if you are unsure or if water sprays or looks dirty.

Call 604-343-1985 if:

• The room or zone stays cold even after valves are opened and thermostats are turned up.

• You’re not comfortable bleeding radiators or touching any valves or piping.

• Multiple rooms on the same floor are cold while others are fine.

Hot Water But No Heating from the Boiler

If you have domestic hot water but the radiators or in‑floor heat stay cold, your boiler or system controls may not be sending heat to the space‑heating side.

Common signs:

• You have hot water at taps and showers, but radiators are cold and the home temperature drops.

• The boiler fires when you run hot water but does not run when only heating is demanded.

What you can check:

• Heating mode on controls: Verify that system controls or thermostats are set to call for heat and not in summer/cooling‑only mode.

• Timer/schedule: Make sure any programmable controls are not set to keep heating off at the time you feel cold.

Call 604-343-1985 if:

• Heating never comes on even when thermostats and controls are correctly set.

• You hear the boiler start briefly then shut down whenever heat is needed.

• You’re not sure whether your system is a combi, system, or conventional boiler and don’t want to risk mis‑adjusting controls.

Boiler Running But Radiators Are Cold or Partly Cold

Sometimes the boiler appears to run, but radiators or in‑floor loops are not heating properly.

Typical symptoms:

• Radiators warm at the bottom but cold at the top.

• Radiators cold on one side and hot on the other.

• In‑floor zones with uneven warm and cold patches.

What you can check:

• Radiator valves: Confirm each radiator’s valves are open and not blocked by furniture or painted shut.

• Obvious air: If you are experienced and have a radiator key, you can carefully bleed air from radiators one by one, watching for water to flow steadily.

Call 604-343-1985 if:

• Radiators stay cold or uneven after valves are opened and air is bled.

• You hear loud gurgling, banging, or knocking in pipes or radiators.

• You are unsure how to safely bleed radiators or suspect low system pressure.

Boiler Keeps Losing Pressure or Shutting Off

Many boilers monitor water pressure and will lock out if the pressure is too low or if they detect certain faults.

Signs of pressure or lockout problems:

• The boiler display or gauge shows low pressure.

• You’re frequently resetting the boiler or it shuts down shortly after starting.

• You see error codes or indicator lights you don’t recognize.

What you can check:

• Visible leaks: Look carefully for damp spots, drips, or pooling water around the boiler, nearby piping, and accessible radiators.

• Pressure gauge: Without touching any valves, note whether the gauge appears very low; this is useful information to share when you call.

Call 604-343-1985 if:

• The boiler keeps losing pressure or shutting down.

• You see any leaks, rust, or signs of corrosion.

• You’re not sure how to safely adjust or refill the system—do not guess with fill valves or safety devices.

Boiler Making Banging, Knocking, or Whistling Noises

Unusual noises from your boiler or heating system can be early warnings of bigger issues.

Common noises:

• Banging or knocking in pipes or radiators when the boiler starts or stops.

• Whistling, kettling, or high‑pitched sounds from the boiler itself.

• Loud humming or grinding from pumps or fans.

What you can do:

• Note when the noise happens: at startup, when shutting down, or continuously.

• Check that nothing is physically touching or pressing on exposed piping near the boiler.

Call 604-343-1985 if:

• Noises are loud, new, or getting worse.

• Noises are accompanied by loss of heat, error codes, or system shutdowns.

• You feel uncomfortable running the system because of the sounds.

Safety First: When to Turn the Boiler Off Immediately

Certain warning signs mean you should turn the system off (if it is safe to do so) and get professional help:

• Smell of gas near the boiler or gas piping.

• Strong burning, melting plastic, or electrical smells.

• Soot, scorch marks, or black staining on or around the boiler.

• You or family members feel unwell (headaches, nausea, dizziness) when the boiler is running, which can be a sign of possible carbon monoxide issues.

If any of these apply, switch the boiler off at its dedicated switch and/or breaker if you can do so safely, leave the area if necessary, and call 604-343-1985. In case of a suspected gas leak or carbon monoxide emergency, follow local emergency instructions immediately.

Simple Boiler Checks You Can Try vs When to Call Budget

Safe basic checks you can usually try:

• Making sure thermostats are set correctly and have working batteries.

• Confirming the boiler power switch is on and looking for a tripped breaker once.

• Ensuring radiator valves are open and not physically blocked.

• Observing, but not adjusting, system pressure, error codes, and unusual noises so you can describe them clearly.

Call Budget Heating & Plumbing at 604-343-1985 when:

• You have no heat anywhere and basic checks haven’t fixed it.

• You have heat in some areas but not others, and valves and thermostats appear correct.

• The boiler shows error codes, keeps resetting, or loses pressure.

• You notice leaks, rust, scorch marks, unusual smells, or loud noises.

• You’re simply not comfortable touching anything and want a professional to handle it.

Professional Boiler Help for No‑Heat Problems in the Lower Mainland

Boiler systems are reliable when properly installed and maintained, but “boiler not heating” is a serious comfort and safety issue that shouldn’t be ignored. Whether your whole house is cold, one floor has no heat, or radiators are only partly warm, a proper diagnosis protects both your home and your equipment.

Budget Heating & Plumbing provides boiler troubleshooting, repair, installation, and maintenance throughout the Lower Mainland and Fraser Valley, including North Vancouver, West Vancouver, Vancouver, Burnaby, New Westminster, Coquitlam, Port Coquitlam, Port Moody, Surrey, Langley, Abbotsford, Chilliwack, and nearby communities. If your boiler is not heating or you’re worried about running it safely, call 604-343-1985 to speak with a technician and book service.

Boiler Not Heating: Frequently Asked Questions

Why is my boiler not heating my house?

Common reasons include thermostat or control issues, low system pressure, air in radiators, failed pumps or valves, ignition problems, or safety lockouts. If basic checks (thermostat settings, power, visible leaks) don’t reveal anything obvious, call 604-343-1985 so a technician can diagnose the boiler safely.

Why do I have hot water but no heating from my boiler?

If your taps and showers are hot but radiators or in‑floor heating stay cold, the boiler may not be switching into heating mode due to a faulty valve, control, thermostat, or sensor. This usually requires a professional to test components and controls—call 604-343-1985 to book a service visit.

Why are some radiators hot and others cold?

This often points to closed or stuck valves, trapped air, balancing issues, or circulation problems on specific branches of the system. You can check that radiator valves are open; if radiators remain cold or only partly warm, call 604-343-1985 for help with bleeding, balancing, and diagnosing circulation issues.

Why does my boiler keep losing pressure?

Pressure loss is commonly caused by leaks in the system, faulty expansion vessels, or relief valves that are discharging. Repeatedly topping up pressure without fixing the underlying problem can damage the boiler, so if you see low pressure or frequent lockouts, call 604-343-1985 to have the system inspected.

Is it safe to reset my boiler when there is no heat?

One reset after a brief power issue or known cause can be reasonable, but repeated resets without understanding the fault can be unsafe and may damage components. If your boiler keeps locking out or showing error codes, stop resetting it and call 604-343-1985 so a licensed technician can investigate.

When should I turn my boiler off and call for emergency help?

Turn the boiler off (if it is safe to do so) and seek immediate help if you smell gas, notice strong burning or electrical smells, see soot or scorch marks, or if people feel unwell (headaches, nausea, dizziness) when the boiler runs. In any of these situations, shut the system down, follow local emergency instructions if needed, and call 604-343-1985.