In a two-story house, heating systems need to work extra hard to evenly distribute warm water throughout the system. Trapped air can build up, especially in the upper radiators, causing cold spots and inefficient heating. Bleeding your radiators regularly helps to:
- Improve overall heating performance
- Reduce energy bills
- Extend the life of your boiler
- Eliminate strange noises from your pipes
Signs Your Radiators Need Bleeding
Knowing when to bleed your radiators can prevent bigger problems later. Watch out for:
- Cold spots on top of the radiator
- Gurgling or banging noises
- Radiator not heating evenly
- The radiator is cold while others are hot
Tools You’ll Need
Make sure you have the following before you begin:
- Radiator key (or a flathead screwdriver for some models)
- An old towel or a cloth
- A small bowl or container to catch water
- Gloves (optional but recommended)
- Boiler manual (in case you need to repressurize it)
Step-by-Step Guide to Bleed Radiators in a 2-Story House
Step 1: Turn Off the Heating System
Switch off your central heating and wait for 30 minutes. This prevents hot water from spilling out and allows the air to settle at the top of your radiators.
Step 2: Start with the Radiators Upstairs
Always begin with the radiator on the top floor, farthest from the boiler. Air tends to rise, so the highest radiators usually trap the most.
Step 3: Use the Radiator Key
Insert the key into the bleed valve (usually at the top side of the radiator) and slowly turn counterclockwise until you hear a hissing sound — that’s the air escaping.
Step 4: Catch the Drips with a Cloth or Container
As soon as water starts trickling out, close the valve by turning the key clockwise. This means all the air has been released.
Step 5: Wait for the Hiss to Stop
Let the air release completely — this may take a few seconds to a minute. Don’t let too much water escape.
Step 6: Repeat Downstairs
Once all upstairs radiators are bled, move to the ground floor. Follow the same process — farthest radiator first, then work toward the boiler.
Step 7: Re-pressurize Your Boiler
After bleeding all radiators, check the pressure gauge on your boiler. If it has dropped below the recommended level (usually 1-1.5 bar), you’ll need to top it up using the filling loop.
Important Safety Tips During the Process
- Always wait for radiators to cool before bleeding
- Do not force the bleed valve if it’s stuck
- Use gloves to avoid burns or dirty water stains
- Keep towels nearby to prevent floor damage
How Often Should You Bleed Your Radiators?
At least once a year — ideally before winter hits. But if you notice uneven heating or strange noises, it’s time to bleed them again.
Common Mistakes to Avoid
- Bleeding while the heating is on
- Forgetting to check the boiler pressure afterward
- Letting too much water escape
- Ignoring small drips that indicate valve issues
Benefits of Proper Radiator Maintenance
- Saves energy and money
- Keeps your home evenly heated
- Prevents breakdowns and costly repairs
- Increases system lifespan
FAQs – Bleeding Radiators in Two-Story Houses
Should I always start upstairs when bleeding radiators?
Yes. Air rises and typically accumulates in higher radiators first.
How long does it take to bleed each radiator?
Around 5 minutes per radiator — longer if there’s a lot of air trapped.
What if no water comes out when I bleed?
It could mean your system pressure is too low. Repressurize your boiler and try again.
Is it normal to bleed radiators multiple times a year?
If your system collects air frequently, yes. Otherwise, once a year is typical.
Do I need to bleed all radiators in the house?
Yes, even if some seem to be working fine. It ensures balanced heating.
Can I bleed radiators without a key?
Some models accept a flathead screwdriver, but using a proper key is safer and more precise.
Final Thoughts & Heating Efficiency Advice
Bleeding your radiators is a quick but powerful way to maintain a cozy home. Especially in a 2-story house, it ensures consistent warmth from top to bottom and keeps your heating system running smoothly.
For best results, combine bleeding with yearly servicing and regular pressure checks. A warm house doesn’t just feel good — it saves you money in the long run.
