Run capacitor
Common no-start and weak-compressor failure point. Match the microfarad and voltage rating.
Burnham Boiler E2 Error Code — What It Means
E2 on a Burnham boiler indicates a pressure switch fault — the control system detected that the pressure switch did not close when the inducer started, or opened unexpectedly during operation. Burnham’s boiler control platform (used across the Series 2, ES2, and IN series) requires proof of negative draft pressure before allowing ignition. E2 is specifically the “pressure switch failed to close” or “pressure switch opened during operation” fault. The boiler locks out and must be manually reset.
Common Causes
- Blocked condensate drain on condensing models — Burnham condensing boilers generate significant condensate. A blocked drain allows water to back up into the heat exchanger or pressure hose, impeding inducer airflow.
- Clogged or cracked pressure switch hose — The small rubber or silicone hose between the inducer housing and the pressure switch fails from heat cycling. Cracks and kinks are common on older units.
- Failed inducer motor — A worn inducer bearing reduces airflow, and the switch never sees adequate negative pressure to close.
- Blocked flue or air intake pipe — Ice at the intake terminal (a common winter problem on PVC-vented Burnham boilers), bird nests, or debris can reduce airflow enough to prevent the pressure switch from closing.
Step-by-Step Fix
- Reset the lockout — Press the reset button on the control board or disconnect power for 30 seconds, then restore.
- Check the flue and intake terminals — Walk outside and visually inspect both the exhaust and intake pipe terminations. Clear any ice, debris, or blockage.
- Inspect the pressure switch hose — Remove both ends and blow through the hose. If moisture is present, clear it and check the condensate drain system.
- Verify the condensate drain is flowing — On condensing Burnham boilers, confirm the condensate trap is clear and the drain line is not blocked. A filled trap starves the inducer of airflow.
- Listen to the inducer — With power restored and a heat call active, the inducer should sound strong. A laboring or intermittent inducer needs replacement.
- Test the pressure switch — Disconnect the hose and use a manometer or vacuum pump to confirm the switch closes at its rated water column value. Replace a switch that fails to close at spec.
- Reset and test through a full cycle — Restore power, run a heat call, and confirm the boiler fires and reaches setpoint without re-triggering E2.
Parts Often Needed
| Part | Notes |
|---|---|
| Pressure switch | Match the WC rating printed on the Burnham label |
| Pressure switch hose | Use silicone tubing rated for the temperature; rubber degrades quickly |
| Inducer motor | Match Burnham model and HP rating |
Need Replacement Parts?
Before ordering, match the water-heating part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
When to Call a Pro
If the condensate drain system requires significant disassembly, or if the inducer motor needs replacement and you are not comfortable with gas appliance wiring, contact a licensed plumber or HVAC technician experienced with hydronic systems.