Bosch boiler troubleshooting

Bosch is a leading brand of household appliances in the world market. Once a small company founded in 1886 by an engineer-electrician, at present, the company is among the world’s leading suppliers of consumer products, including boilers. The slogan of the company is: “Better to lose in profit than in trust of our buyers,” – is reflected throughout everything, including its troubleshooting system. It is represented below in a chart form.

Bosch WM 12 boiler troubleshooting

PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION
Chain saw fails to operate Kickback brake is activated Pull activation lever for kickback brake (hand guard) 5 back in position O
Plug not connected Connect plug
Mains socket faulty Use another socket
Extension cable damaged Check cord, replace
Fuse faulty/blown Replace fuse
Chain saw operates intermittently Extension cable damaged Check cord, replace
External or internal wiring defect Contact your Bosch Service Centre
On/Off switch 2 defective Contact your Bosch Service Centre
Saw chain dry No oil in reservoir Refill oil
Vent in oil filler cap 4 clogged Clean oil filler cap 4
Oil passage clogged Clean oil passage
Brake does not stop saw chain Kickback brake/run-down brake defective Contact your Bosch Service Centre
Saw chain/guide bar hot No oil in reservoir Refill oil
Vent in oil filler cap 4 clogged Clean oil filler cap 4
Oil passage clogged Clean oil passage
Chain tension too high Tension saw chain
Dull saw chain Sharpen saw chain or replace
Chain saw rips, vibrates, Chain tension too loose Tension saw chain
does not saw properly
Dull saw chain Sharpen saw chain or replace
Chain worn out Replace saw chain
Chain teeth are facing in the wrong direction Reassemble with chain in correct direction

Bosch R 30 boiler troubleshooting

PROBLEM CAUSE REMEDY
Desired room temperature is not reached Thermostatic valve(s) set too low Increase thermostatic valve setting (s)
Temperature control for CH flow set too low Increase CH flow temperature control setting
Air trapped in heating system Bleed radiators and heating system
Desired room temperature exceeded by large amount Radiators are too hot Turn down thermostatic valves
Temperature rises instead of falling Clock is incorrectly set Check setting
Room temperature too high in Economy mode Building retains heat well Start Economy mode sooner
No display or display unit does not respond Momentary power failure Switch off appliance at master switch, wait a few seconds and switch on again
Storage Tank doesn’t warm up Temperature control is too low Turn the temperature control to the desired temperature

Bosch ZBR35-3A boiler troubleshooting

PROBLEMS CAUSE/SOLUTIONS
Combustion noise too loud; rumbling noises * Insert code plug correctly; replace if defective.
* Check gas type.
* Check inlet gas pressure; adjust if defective.
* Check flue gas system; clean or repair if defective.
* Check gas/air ratio in the combustion air and flue gas; replace gas valve if defective.
Flow noises * Set pump speed correctly to match maximum output.
* Set pump mode.
Heating-up takes too long * Set pump speed correctly to match maximum output.
* Set pump mode.
Flue gas readings incorrect; CO levels too high * Check gas type.
* Check inlet gas pressure; adjust if defective.
* Check flue gas system; clean or repair if defective.
* Check gas/air ratio in flue gas; replace gas valve if defective.
Violent ignition, poor ignition * Check gas type.
* Check inlet gas pressure; adjust if defective.
* Check power supply.
* Check electrodes for visual damage; replace if defective.
* Check flue gas system; clean or repair if defective.
* Check gas/air ratio; replace gas valve if defective.
* Check gas valve; replace if defective.
* Check burner; replace if required.
DHW has unpleasant odor or has a dark color * Perform thermal disinfection of the DHW circuit.
* Replace sacrificial anode in the tank (if installed).
* Consult local water department.
Set supply temperature (e.g. of the FW200 control) exceeded * Switch off automatic anti-cycle timer, i.e., set value to 0.
* Set the required anti-cycle timer, e.g. default setting of 3 minutes.
Condensate in air box * Insert diaphragm in the mixer unit per installation instructions; replace if defective.
DHW temperature is not reached (combi boiler 2WB..-3A only) * Insert code plug correctly; replace if defective.
* Check whether voltage (120 VAC) is present between terminal 1 and terminal 3; repair if defective.
* Check turbine; replace if defective.
Heatronic is flashing (i.e. all buttons, all display segments, burner indicator etc. are flashing) * Replace fuse Si 3 (24 V) (6.3 A fuse according to IEC default).