Tankless Combi Boiler Repair Experts
Diagnosing & Fixing All Tankless Combi Error Codes – Fast, Reliable & Guaranteed
Is your tankless combi boiler flashing a cryptic error code? Don’t panic — we’re here to help.
At Pipe Doctor Home Services, we specialize in repairing all makes and models of tankless combi boilers. If you’re staring at an error code like E003, E012, or E110, you’ve come to the right place.
Below is a complete list of the most common error codes found on popular tankless combi boiler systems, what they mean, and why it’s time to call the pros.
Tankless Combi Boiler Error Codes & Meanings
E002 – Overheating – typically due to circulation issues
E003 – Ignition failure – burner won’t ignite
E004 – False flame detection – unit thinks there’s a flame when there isn’t
E005 – Flame loss – burner ignites but then goes out
E006 – High water temperature – system safety shutdown
E007 – Circulation pump failure or blockage
E008 – Air in the system or low flow rate
E009 – Abnormal flow sensor reading
E010 – Exhaust blockage or venting issue
E011 – Intake air restriction or issue with combustion air
E012 – Flame loss during operation
E016 – Heat exchanger over-temperature
E017 – PCB communication error
E018 – Sensor disconnection or failure
E021 – Abnormal exhaust temperature
E027 – Hot water outlet sensor error
E028 – Return sensor fault
E031 – 3-way valve issue
E032 – Condensate trap or line blockage
E035 – Fan motor error
E037 – Internal sensor malfunction
E040 – Abnormal pressure detected
E046 – Internal temperature sensor error
E047 – Abnormal operation temperature
E060 – Water adjustment valve fault
E061 – Incorrect DHW sensor reading
E062 – Domestic hot water temperature too high
E110 – Exhaust gas temperature too high – potential danger
E351 – Gas valve communication error
E352 – Flow sensor problem
E353 – Heat exchanger temperature rise too fast
E354 – Boiler temperature differential too large
E429 – Internal control board fault
E432 – Ignition module error
E434 – Flow sensor connection issue
E438 – DHW inlet sensor error
Why These Error Codes Matter
These aren’t just annoying blinking lights — they’re early warnings of a system failure that could lead to:
• No hot water or no heat
• Frozen or damaged pipes
• Overheating and shutdowns
• Carbon monoxide risk (with venting issues)
• Costly breakdowns if ignored
What to Expect from Our Repair Service
- Fully licensed & insured technicians
- Same-day or next-day service available
- Diagnostic + repair in one visit whenever possible
- 24-month satisfaction guarantee
- Transparent pricing – no surprises
- Stocked trucks with genuine parts for most models
Book Your Tankless Combi Repair Today
Don’t waste time Googling error codes — let the pros handle it.
Call us now to schedule a diagnostic service visit. One of our expert technicians will arrive in a clearly marked vehicle, properly uniformed, and ready to solve your problem.
Call Now: (516) 348-6300
Serving Nassau County, Long Island
“I Had E003 – No Hot Water for 2 Days! These Guys Fixed It in One Hour.”
“Called Pipe Doctor after my boiler kept flashing E003. Another company told me I needed a new unit. These guys came, diagnosed a bad ignitor, replaced it, and I was back in hot water an hour later. Life savers!”
— Rachel M., Rockville Centre NY
Pro Tip:
Never reset your boiler repeatedly to clear the code — that can cause permanent damage. Let a certified technician properly diagnose the problem.
