Worcester oil boilers: internal versus external siting

What is actually going on with internal versus external oil boiler siting

An external unit frees up a garage, outbuilding or utility room entirely, at the cost of slightly more exposed pipework and a casing built to shrug off rain and frost rather than the more compact internal enclosure. Internal models are typically quieter to stand near and marginally simpler to service, since the engineer isn't working in a garden in January. Either format uses broadly the same burner and controls internally.

Internal versus external oil boiler siting — the facts that change the job

• External units free internal space entirely for other use
• Internal units are more sheltered for winter servicing access
• Both formats need the same OFTEC-compliant tank and fire valve setup
• External casings are built to resist rain and frost ingress
• Flue and combustion air routing differs between the two formats

Questions we get asked

Is an external oil boiler less reliable in winter?

Not inherently — they're designed for outdoor use — but very exposed sites benefit from extra weather protection or a sheltered position.

Can I switch from internal to external on replacement?

Often yes, subject to a suitable outside wall, tank position and flue route being available; we confirm on survey.

Where we deal with this

• Wookey Hole (BA5) · 11 mi
• Selwood (BA11) · 8 mi
• Farrington Gurney (BS39) · 4 mi
• Burrington (BS40) · 10 mi
• Backwell (BS48) · 13 mi