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Radiant Floor Heating/Propane-fired Buderus GB142 problem


I have a Buderus GB142 boiler heating my house with radiant floor heat. It was installed in 2008 with the propane adapter kit. The first year it worked fine but in the second year it started failing with 6A error codes. The installer contacted the local Buderus rep who recommended cleaning the boiler fins with mineral oil. That took care of the problem for a while but the next year he replaced the flame sensor and cleaned the fins. This year the flame sensor was replaced again and the fins cleaned but I am still getting the 6A failure every few days.
The Buderus people say this boiler has issues running on propane.
They told me that my boiler only had a 2 year warranty even though the current ones have a 5 year warranty.
I saw a video on youtube talking about this boiler having problems with generator power and the solution was to replace the control unit. In the video they changed the controller from version 3.5 to version 3.6
My controller is version 3.5. Do you think upgrading the controller to version 3.6 would help my problem?
Do you have any suggestions on fixing this problem?

Propane is a less-than-ideal fuel, as it often "doped" for weather and other conditions dependent on source, destination and application. When used as a fuel source for any condensing boiler, a combustion test and proper, learned, adjustment, by a Buderus certified technician, is absolutely critical.

As to whether your particular Buderus GB142 will benefit from a new control, I cannot say without a hands-on inspection.

The warranty you speak of is for controls and is quite liberal, as the average warranty, for all but the heat exchanger, is typically one year (more than enough in most cases).

Though we install and service Buderus boilers, including the Gb142, we are leaning toward the relatively new Lambda burner technology, currently only available from Viessmann. This new burner is self-adjusting for fuel quality and looks very promising for this challenging application.

You will want to make sure that combustion is clean and plan on annual maintenance (a must for all condensing boilers regardless of fuel source).  

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Morgan M. Audetat


Radiant panel heating design, including floors and ceilings, European wall panels and snow melting for residential and light commercial buildings..............................................................-Master of Steam and Hot Water,City of Minneapolis....................................................--- Master Plumber, State of Minnesota...........


30 years..... Charter Board Member - Radiant Panel Association, former manufacturer of condensing boilers, former national distributor of radiant floor products, son and apprentice of mechanical & plumbing contractor. Current mechanical/plumbing contractor specializing in hydronic based, integrated HVAC systems. Radiant floor heating/cooling. Snow Melting. Condensing Boilers. Indirect water heaters. System design, consulting and technical training world-wide. Licensed contractor, designer, installer and consultant.

B.S. University WI 1981 CONTINUING EDUCATION: Viessmann Condensing boiler and Solar water heating certification 2010, N.D.S.U. Lead Worker RRP certification 2010, Knight condensing boiler certification 2009, Wrightsoft Manual J CAD certification 2009, RPA Designer & Installer Certification 2008, Nate Hydronic/Forced Air Certification 2008, Uponor/Wirsbo advanced design school certification 2007, Buderus Wall-hung certification 2007, Power Limited License (low voltage controls) 40 CE credits 2005, Basic Hydronic Certification IPEX & Northern Alberta Institute of Technology 1998, Charter Board Member - Radiant Panel Association 1994, Residential Off-Electric to Hydronic Conversion Heating School Canadian Hydronics Council 1994, B&G Little Red School House 1993, Rood Utilities (now Auburn Technical Institute) Oil Burner School 1993 ,Tekmar Controls residential and commercial 1993, Division Manager and Advanced Hydronic Seminar Instructor for the first Exclusively Hydronic Radiant Floor Distributor in the USA 1990, Hydronic Radiant Heating Association Workshop participant with Richard c. Bourne, PE spring 1988, Master Plumbing, Hydronic, Solar Course Red Rocks Community College 1987.

Awards and Honors
2009 System Showcase Award - Radiant Panel Association

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