How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask John Your Own Question
John, restaurant equipment technician
Category: Appliance
Satisfied Customers: 2136
Experience:  25+ years experience. I'm now employed by a commercial cooking equipment service company
Type Your Appliance Question Here...
John is online now
A new question is answered every 9 seconds

Bosch Highflow YS2431R instant gas HWS10 years old). Tries

This answer was rated:

Bosch Highflow YS2431R instant gas HWS10 years old). Tries to light, then flashes error 12 on control and reduces water flow. Water is slightly warmed for a moment so ignition has taken place for a short while. An error list would or any other info would be great. Thanks, AM

The spark ignition wire, in addition to lighting the burner, serves as a flame proofer to make certain the flame is lit. Over time the wire tends to pull away from the flame front, and the signal to the ingition module gets too weak to keep the gas valve open.

The solution is usually to gently bend the wire back toward the burner flame.

If my answer helps you, please click on the 'accept' button.

Thank you for choosing justanswer.

John and other Appliance Specialists are ready to help you
Customer: replied 7 years ago.

Thanks John, your right on the mark. I've just discovered the gas pressure is low. That would mean the falme is a bit small to react with the wire.

Yes, that's correct. If the gas pressure gets too low for the burner to operate correctly, replace the gas pressure regulator.