Technical Service Bulletin
Issue: Boiler will not start the trial for ignition
▪ Vitodens 200, WB2B Series (all models)
▪ Vitodens 200-W, B2HA Series (models 19 to 100, 285 to 352)
▪ Vitodens 200-W, B2HB Series (all models)
▪ Vitodens 222-F, B2TB Series (all models)
The information in this bulletin is intended exclusively for licensed heating contractors, and is NOT intended for the end user. This material is NOT intended to take the place of the information contained in the manuals shipped with the product.
Use of this information by unqualified personnel may result in property damage, personal injury or death.
End users are asked to contact a qualified contractor for all installation and service work. If you need assistance finding a contractor in your area, contact your Viessmann Sales Representative, or use our Contractor Locator.
By hitting "Yes" below you confirm that you have read, understood and agree to this warning, that you are licensed and hold the current, appropriate licences to work on said equipment in the location and/or jurisdiction of installation.
Boiler will not start the trial for ignition, and no fault is displayed on the boiler control.
The boiler pump or DHW pump is running.
Coding address "38" has a value of "3".
Boiler control does not detect water flowing through the heat exchanger.
Turn the boiler off, and place a jumper in plug 33 (the flow switch counter plug). Then turn the boiler back on again.
After the boiler starts, determine the reason why the flow switch is not closing – e.g. check if there is a faulty pump or flow switch, and check if the heat exchanger is blocked. After finishing the tests, turn the boiler off and remove the jumper from plug 33.
The jumper must be removed after troubleshooting.