By Simon Stokes, Challenger Heating Services
This is one of the most common questions we hear — and it’s a fair one.
The short answer? Maybe, but not always.
Let’s break it down so you understand when and why a new gas pipe might be needed.
Why Gas Pipes Matter More With Modern Boilers
Boilers today aren’t like the ones from 20+ years ago.
Back then, boilers were rated C or lower for energy efficiency. Now, all new boilers must be A-rated — meaning over 90% efficiency.
That’s great news for performance, but it comes with a catch:
New boilers are designed differently, and they demand more from the gas supply.
Why Gas Pressure Matters
When we install a boiler, we check:
- The gas pressure at the meter
- The gas pressure at the boiler
By law, the boiler can only lose up to 1 millibar between the meter and the appliance.
Example: If we get 20.8mb at the meter, we need at least 19.8mb at the boiler.
If the reading drops to 16mb, that’s non-compliant and unsafe, and could void your boiler warranty.
When You Might Need a Bigger Gas Pipe
Sometimes, the existing 22mm gas pipe isn’t enough.
A new boiler may need:
- A 28mm pipe (or at least an upgrade on part of the run)
- Fewer bends, shorter runs, or even reducing boiler size (e.g., 30kW → 24kW) to make it work
We calculate this carefully using tools, not guesswork — looking at:
- Boiler size
- Pipe length
- Number of bends
- Existing pipework
What About Installation?
Upgrading gas pipes can be simple or complex, depending on:
- Where your boiler is (near the meter = easier; across the house = more work)
- Floor types (solid floors, tiles, Karndean make access harder)
- Route options (under floors, in lofts, through walls, outside, or underground)
If you’re planning new flooring or fitted furniture, it’s smart to check your gas pipes first.
A Note on Iron Gas Pipes
Older homes sometimes still have iron gas pipes.
While they might work, they corrode inside and create rust particles.
A new boiler can suck those particles in, risking blockages or breakdowns, another reason we sometimes recommend replacing them.
Safety First
If we find a gas leak, the pipe must be replaced.
There’s no workaround — safety always comes first.
Final Thoughts: Do You Need a New Gas Pipe?
Maybe — but maybe not. Here’s what to remember:
- We only recommend it if your system needs it for safe, compliant operation.
- Planning ahead can save you hassle and extra cost.
- Many customers say upgrading was easier than they expected.
Most importantly: It’s not just about performance, it’s about protecting your home and family.