If your heating’s on but one room still feels freezing, you’re not alone. It’s one of the most common problems in UK homes — especially in winter when the boiler’s working overtime and your bedroom still feels like a fridge.
The good news? There’s always a reason behind it, and most fixes are simple.
This guide breaks down real UK causes, real UK fixes, and no pointless waffle.
🔥 1. The Room Is Losing Heat Faster Than It’s Being Heated
Most UK houses are old.
Single-brick walls, tiny gaps, old windows — they leak heat like crazy.
Common heat-loss culprits in UK homes
- Cold air getting in through window frames
- Poor insulation in external walls
- Bare floorboards letting draughts up
- Heat escaping into the loft
- Gap under the bedroom door
- Thin curtains that let cold radiate in
How to fix it (cheap, practical fixes)
- Add thermal curtains or blinds
- Use draught excluders around the door
- Seal gaps around window frames (£5 tube of sealant)
- Add a thick rug to stop cold rising
- Check for cold air “streams” with your hand
- Use 3M thermal film if windows are old
Most of this costs under £10–£20 per fix and makes a big difference quickly.
🔥 2. The Radiator Isn’t Giving Out Enough Heat
This is the most common reason.
Is the radiator warm at the top but cold at the bottom?
→ That’s sludge.
Is it warm at the bottom but cold at the top?
→ That’s trapped air.
Is one radiator cold but others are hot?
→ That’s a balancing issue.
Simple fixes you can do right now
- Bleed the radiator (takes 10 seconds)
- Check the TRV (thermostatic valve) is open
- Turn all radiators on full for 20 mins
- Then slightly close the hottest ones → this pushes more heat to the cold room
- Make sure the radiator isn’t blocked by a bed, sofa or wardrobe
If sludge is the issue, radiators need flushing — not urgent, but worth doing eventually.
🔥 3. The Boiler Can’t Supply Enough Heat to All Rooms
Old boilers, low pressure, or undersized systems struggle with multiple rooms.
Signs your boiler is the issue
- Radiators get hot, then go cold
- Your boiler pressure is under 1 bar
- You hear gurgling or kettling noises
- Boiler resets randomly
- Hot water is weak AND room heating is weak
Quick fixes
- Check boiler pressure and top up to 1.2 – 1.5 bar
- Remove any airlocks in the system
- Reset the boiler if needed
If you have a big house but a small boiler, this problem becomes noticeable in winter.
🔥 4. The Thermostat Is in the Wrong Room
This is one people never think about.
If your thermostat is in the living room, and the living room gets warm fast, the boiler will shut off…
…while your bedroom upstairs is still freezing.
Fix
Try increasing the thermostat by 1–2°C temporarily.
Or move the thermostat to a more central spot in the house.
You can also use a smart thermostat that monitors multiple rooms.
🔥 5. Cold Rooms Above Garages or Extensions
If your cold room is:
- above a garage
- part of an extension
- at the back of the house
- next to an external wall
…heat loss is usually worse than the rest of the house.
Fixes
- Use thermal curtains (massive difference)
- Add a rug or thick carpet
- Plug draughts along skirting boards
- Use a small oil-filled radiator on a low setting for an hour before bed
These rooms almost always need “supplement heat.”
🔥 6. The Room Is Too Big For the Radiator
Radiators have BTU (heat output numbers).
If the radiator is too small, it simply can’t heat the room — even if it’s fully working.
Signs your radiator is too small
- Room heats VERY slowly
- Radiator gets hot but room stays cold
- Room cools down quickly after heating stops
Fix
Use a BTU calculator and check if your radiator is the correct size.
If not, upgrading the radiator is a game-changer.
🔥 7. Poor Airflow Makes the Room Feel Colder
If your doors are closed all the time, heat can’t circulate properly.
If your doors are open all the time, heat escapes too fast.
Tricky balance.
Fix
Try leaving the bedroom door slightly open
OR
fully closed depending on where your heating source is.
Small adjustments work surprisingly well.
🔥 8. Clothes Drying in the Room Makes It Feel Cold
Wet clothes = insane moisture.
Moisture = cold air.
Drying clothes in a bedroom literally makes it feel colder (and can cause damp).
Fix
Dry in another room or use a heated airer with a door open slightly for airflow.
🔥 9. Use a Secondary Heat Source (Safely)
Sometimes the cheapest fix is just adding a little boost.
The safest low-cost options:
- Oil-filled radiator
- Micathermic heater
- Halogen heater (cheap but warms instantly)
- Electric blanket throw (uses pennies per hour)
Don’t use:
- fan heaters (expensive)
- cheap Chinese fire-risk heaters
Secondary heat is NORMAL in UK homes — don’t feel bad for using it.
🔥 10. The Room Has Damp or Humidity Issues
Cold + damp = freezing.
Wet walls pull heat OUT of the air.
Fix
Use a dehumidifier for 3–4 hours a day.
You’ll notice a big difference in warmth.
⭐ Quick Checklist to Solve a Cold Room
Use this checklist and you’ll almost always find the cause:
✔ Radiator hot top-to-bottom?
✔ TRV valve open?
✔ Room leaking heat?
✔ Curtains thick enough?
✔ Boiler pressure correct?
✔ Thermostat in a good location?
✔ Clothes drying elsewhere?
✔ Room above garage/extension?
✔ Any damp?
Tick these off and your room WILL get warmer.
⭐ Final Thoughts
If your room feels cold while the heating is on, it’s rarely because “the heating is broken.”
It’s usually one small issue that’s easy to fix — draughts, insulation, radiator balance, or airflow.
Try the steps in this guide and you’ll feel a difference immediately.
