John Wood Error Error 3: Pressure Switch Stuck Closed
The air pressure (vent) switch remained closed longer than 5 seconds after the call for heat began, before the blower started. The blower does not start. The control will not allow ignition until a safe vent condition is confirmed. We diagnose and repair it across Greater Vancouver — same-day and after-hours.
The air pressure (vent) switch remained closed longer than 5 seconds after the call for heat began, before the blower started. The blower does not start. The control will not allow ignition until a safe vent condition is confirmed.
John Wood fault codes can vary by model and series. Use this as a guide — the same code can have more than one cause. Our Technical Safety BC–licensed technicians read the code, confirm it against your unit's manual, and diagnose the true cause before any repair.
Likely causes of John Wood error Error 3
- Pressure switch contacts stuck/welded closed
- Incorrect or pinched pressure switch tubing
- Wiring error to the pressure switch
- Defective pressure switch
What you can safely check
- Confirm the blower runs when there is a call for hot water
- Do not bypass the pressure switch
Beyond these checks, do not open the unit or touch gas/electrical parts — BC law requires a licensed gas fitter. Call us for a proper diagnosis.
Parts Are Professionally Installed — Not Sold for DIY
For your safety and to keep your manufacturer warranty valid, BoilerPart.ca does not sell loose boiler parts over the counter or for self-installation. Under BC regulations, gas appliance components must be installed by a licensed gas fitter. Every part we source is genuine OEM and is professionally fitted, tested, and certified by our Technical Safety BC–licensed technicians as part of a complete repair or installation.
Parts often behind John Wood error Error 3
Genuine John Wood parts we supply and professionally install — never for DIY.
Our Guarantees & Warranties
Every repair and installation is backed by genuine parts, licensed workmanship, and a promise to make it right.
Workmanship Guarantee
Every repair and installation is backed by our written workmanship guarantee. If a part we installed fails because of our work, we make it right.
Genuine OEM Parts
We fit only manufacturer-original (OEM) components so your boiler performs to spec and keeps its factory warranty intact.
Manufacturer Warranty Honoured
As an authorised service provider for the brands we work on, our installs preserve and register your manufacturer parts warranty.
Licensed & Insured
All work is completed by Technical Safety BC–licensed gas fitters (Licence LGA0043870, Boiler Permit LBP0046450). We are fully licensed, bonded and insured for your protection.
Up-Front Pricing
You approve the diagnosis and quote before any work begins. No hidden fees and no surprise charges.
Satisfaction Commitment
Backed by the full HVAC resources of CanroHeat.ca and four decades of service in Greater Vancouver since 1985.
John Wood Error Error 3 Repair Across Metro Vancouver
Related John Wood Venting & Combustion Codes
Frequently Asked Questions
Fix John Wood Error Error 3 Today
Licensed John Wood diagnosis and repair with genuine parts — same-day and after-hours across Greater Vancouver.
A Division of CanroHeat.ca · Licensed Gas Fitters · Serving Greater Vancouver since 1985