Worcester Bosch Greenstar GB162 Error Code WB20

Worcester Bosch Home Boiler Minor Mechanical

Model: Greenstar GB162 | Code: WB20

Applicable Systems
Greenstar GB162

Symptoms

The boiler reports a heating circuit short cycle. The heating circuit is cycling too frequently.

Possible Causes

  • Flow rate insufficient through the heat exchanger
  • Temperature differential set too small
  • System balancing issue causing rapid temperature swings

Troubleshooting Steps

  1. Step 1: Verify the system flow rate
    Flow is adequate for the boiler capacity
  2. Step 2: Check the temperature differential setting
    Differential is set correctly
  3. Step 3: Balance the heating system if needed
    System temperatures are balanced

How to Reset

To reset: Adjust the system to prevent short cycling, then clear the alarm.

Source: Worcester Bosch Boiler Manual, Worcester Bosch Group

Category: Home Boiler