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

PROBLEMPOSSIBLE CAUSECORRECTIVE ACTION
Chain saw fails to operateKickback brake is activatedPull activation lever for kickback brake (hand guard) 5 back in position O
Plug not connectedConnect plug
Mains socket faultyUse another socket
Extension cable damagedCheck cord, replace
Fuse faulty/blownReplace fuse
Chain saw operates intermittentlyExtension cable damagedCheck cord, replace
External or internal wiring defectContact your Bosch Service Centre
On/Off switch 2 defectiveContact your Bosch Service Centre
Saw chain dryNo oil in reservoirRefill oil
Vent in oil filler cap 4 cloggedClean oil filler cap 4
Oil passage cloggedClean oil passage
Brake does not stop saw chainKickback brake/run-down brake defectiveContact your Bosch Service Centre
Saw chain/guide bar hotNo oil in reservoirRefill oil
Vent in oil filler cap 4 cloggedClean oil filler cap 4
Oil passage cloggedClean oil passage
Chain tension too highTension saw chain
Dull saw chainSharpen saw chain or replace
Chain saw rips, vibrates,Chain tension too looseTension saw chain
does not saw properly
Dull saw chainSharpen saw chain or replace
Chain worn outReplace saw chain
Chain teeth are facing in the wrong directionReassemble with chain in correct direction

Bosch R 30 boiler troubleshooting

PROBLEMCAUSEREMEDY
Desired room temperature is not reachedThermostatic valve(s) set too lowIncrease thermostatic valve setting (s)
Temperature control for CH flow set too lowIncrease CH flow temperature control setting
Air trapped in heating systemBleed radiators and heating system
Desired room temperature exceeded by large amountRadiators are too hotTurn down thermostatic valves
Temperature rises instead of fallingClock is incorrectly setCheck setting
Room temperature too high in Economy modeBuilding retains heat wellStart Economy mode sooner
No display or display unit does not respondMomentary power failureSwitch off appliance at master switch, wait a few seconds and switch on again
Storage Tank doesn’t warm upTemperature control is too lowTurn the temperature control to the desired temperature

Bosch ZBR35-3A boiler troubleshooting

PROBLEMSCAUSE/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).