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). |