
Product Information Notice
Models: GB125/35
Subject: Field Action - Safety Rework Instructions
Data subject to change without notice | BTC 410004103 C | 01.2020 Bosch Thermotechnology Corp.
All work must be performed by a licensed or qualified
contractor.
Summary
The GB125/35 oil-fired boiler from Buderus may accumulate
combustion debris under certain conditions, resulting in the siphon
becoming clogged. A clogged siphon can block the flue pipe and
consequently may lead to increased formation of carbon monoxide
(CO) in the boiler. If the boiler also has an opening into the
installation room, CO can escape, posing a safety risk.
To minimize the safety risk Bosch is initiating a field action for all
installed GB125/35 boilers.
The following actions are required for the GB125/35 model:
The burner control must be replaced with an upgraded
version (provided by Bosch free of charge).
The existing condensate siphon must be replaced with a new
one (provided by Bosch free of charge).
Replace the heat exchanger clean out cover seal if necessary
(provided by Bosch free of charge).
A labor allowance of up to $300 is available for carrying out this
field action (a separate claim form is available and must be used for
labor reimbursement).
If you have any further questions, please contact us directly on
“GB125/35 Field Action” in the subject line.
Relevant Part Numbers
Description Part Number
Burner Control Unit 8738806487
Condensate Siphon (w/ float) 7747020450
12 mm sealing cord (white)* w/silicone 8718578900
8 mm sealing cord (blue)* w/silicone 8718579535
* The specific sealing cord supplied depends on the date of production of
the boiler. We will supply the correct cord to you.
Required Field Action
-
Burner Control (LMO) Replacement
1. Switch off the boiler and remove the front cover (Fig. 1).
Figure 1
2. There is a clip located on the bottom and the top of the
Burner Control (LMO), which needs to be released for
disassembly. To remove use a flat screwdriver, place it under
the clip and push it upwards to unlock the clip (Fig. 2 and Fig.
3). Afterwards you can remove the LMO (Fig. 4).
Figure 2
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