Incorrect Dip Switch Setting
🔎What the code means
Error 031 indicates “Incorrect DIP switch settings” (sometimes shown as “031 Wrong dip switch setting, possibly LP gas set when the fuel is Natural gas, or vice‐versa”).
In other words: the internal configuration of the unit (via DIP switches on the circuit board) is not set properly for the fuel type, venting, altitude, or other installation parameter.
Steps in Sequence
- Turn off the gas supply and power to the unit.
- Open the front panel (per manual) to access the circuit board with DIP switches.
- Verify the unit’s nameplate: fuel type (Natural vs LP), model, serial, altitude rating.
- Reference the pics below or reference your manual for your model (HS199), set the DIP switches accordingly for your fuel type and installation conditions.
- Ensure no switches are left in ambiguous or intermediate positions.
Re-install the panel, restore power & gas. - Observe if the error goes away and the unit operates correctly.
- If the error persists, further diagnostics may be required (e.g., board fault, installation mismatch) but start with correct switch configuration.
Key Things to Check
Step 1: Verify Fuel Type Setting
Confirm whether your unit is set up for Natural Gas or Propane (LP).If the DIP switches are configured for LP but the unit is using Natural Gas (or vice-versa), it will trigger this error.
Step 2: Check Installation Conditions
On the HS199 series, the manual shows the DIP switch banks for fuel type/high altitude. Is the unit installed at a high altitude? If so, there may be switches that adjust for altitude. The manual shows “High-Altitude Installations” section.
Is the vent length very long or does it differ from standard configuration? Check the parameters below for your venting type and length and adjust your Dip Switch settings accordingly.
Set the DIP Switches Located on the Upper Bank for Venting
Steps to take after you confirm all settings are correct for your boiler conditions:
Reset after adjustment
After adjusting DIP switches, power the unit off, wait a minute, then power it on again so it can read the settings.
Monitor whether the error clears, or if a different error appears.
⚠ Safety & professional service note
Because this error involves internal configuration of the gas appliance, if you’re not experienced with gas-fired equipment you should shut the unit off and call a qualified service technician. Improper settings can lead to unsafe operation (combustion problems, carbon monoxide risk, etc.).
The manufacturer manuals indicate service procedure is for qualified professionals.