To add an additional radiator to your central heating system, shut off the heating, drain the system, install the radiator and connect it to the existing pipework.
Adding a radiator to your central heating system can improve comfort in cold rooms. This guide covers everything from planning to installation. Follow these steps to expand your heating system properly.
Assess Your Boiler Capacity
Before adding a radiator, check if your boiler can handle the extra load. Most combi boilers between 24-30 kW can support 10-12 radiators. Larger homes may need a 30-42 kW unit.
Calculate your total heat demand:
| Room Type | BTU Requirement |
|---|---|
| Small bedroom | 4,000-6,000 BTU |
| Medium living room | 8,000-12,000 BTU |
| Large kitchen | 10,000-15,000 BTU |
For proper radiator sizing, use a BTU calculator. If your boiler struggles with demand, consider upgrading to a more powerful gas heater.
Choose Radiator Location
Optimal Placement
Best locations for new radiators:
- Under windows (counteracts cold drafts)
- Against exterior walls
- In frequently used cold spots
Clearance Requirements
- 125mm from floor
- 50mm from walls
- 100mm from window sills
Installation Process
Tools and Materials Needed
- Radiator brackets
- PTFE tape
- Pipe cutter
- Adjustable spanner
- Bleed key
Step-by-Step Installation
- Turn off boiler and drain system
- Identify nearest flow/return pipes
- Mark wall for bracket placement
- Secure brackets with wall plugs
- Attach valves with PTFE tape
- Connect to existing pipework
- Refill system and bleed air
For complex installations, consider a licensed plumber to ensure proper connections.
Balancing Your System
After adding a radiator, you must balance the system:
- Turn all radiators to maximum
- Note which heat up fastest
- Adjust lockshield valves on hot radiators
- Repeat until even heat distribution
Maintenance Tips
- Bleed radiators annually
- Check for leaks monthly
- Consider a power flush every 5 years
- Insulate pipes to improve efficiency
For older systems, upgrading to a modern thermostat can improve control.
Common Mistakes to Avoid
- Oversizing the radiator
- Poor pipe sloping (causes air locks)
- Incorrect valve installation
- Forgetting to bleed the system
Always follow manufacturer guidelines for your specific heating system. Proper installation ensures efficient operation and prevents damage to your boiler.
