HTP Error A05: Gas Valve Relay Fault
The control detected a gas valve (GV) relay failure (not opening, not closing, or general relay error) and locked out for safety. The boiler will not fire. We diagnose and repair it across Greater Vancouver — same-day and after-hours.
The control detected a gas valve (GV) relay failure (not opening, not closing, or general relay error) and locked out for safety. The boiler will not fire.
HTP 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 HTP error A05
- Failed gas valve relay on the control board
- Faulty gas valve coil or wiring
- Control board fault
- Loose gas valve harness connection
- Internal control self-check failure
What you can safely check
- No safe homeowner internal check; record the A05 code for the technician
- Confirm the boiler has power and the thermostat is calling for heat
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.
Error A05 usually leaves you without heat or hot water and can indicate a safety-related fault. Don't keep resetting it — call for priority after-hours HTP repair.
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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 HTP error A05
Genuine HTP parts we supply and professionally install — never for DIY.
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HTP Error A05 Repair Across Metro Vancouver
Frequently Asked Questions
Fix HTP Error A05 Today
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