Giant Error 12: Temperature adjust button stuck closed
One of the temperature adjust buttons on the control is stuck (sensed continuously closed). The control keeps regulating at the last setting but settings cannot be changed until cleared. We diagnose and repair it across Greater Vancouver — same-day and after-hours.
One of the temperature adjust buttons on the control is stuck (sensed continuously closed). The control keeps regulating at the last setting but settings cannot be changed until cleared.
Giant 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 Giant error 12
- Object leaning against the front of the control pressing a button
- A temperature adjust button physically stuck
- Defective control if buttons cannot be freed
What you can safely check
- Make sure nothing is leaning against or pressing the front of the control
- Lightly press and release each button once to free a stuck button
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 Giant error 12
Genuine Giant 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.
Giant Error 12 Repair Across Metro Vancouver
Frequently Asked Questions
Fix Giant Error 12 Today
Licensed Giant 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