Worcester Bosch Boiler Problems
Worcester Bosch boilers are renowned for their reliability and efficiency, but like any mechanical system, they can sometimes encounter problems. In this article, we delve into a forum discussion where an individual sought help with wiring a new boiler into an existing Y-plan heating system. The task seemed straightforward but raised questions about the pump overrun and the correct wiring procedure. We explore the problem, the forum’s responses, and the eventual resolution to provide insights into dealing with Worcester Bosch boiler issues.
The Wiring Challenge
The forum member initiated the discussion by describing their task of wiring a new Worcester Bosch boiler into an existing Y-plan system. The main objective was to provide a permanent live to the boiler. However, complications arose as the wiring was not as straightforward as expected.
The specific problem revolved around the pump overrun. In a Y-plan system, the overrun pump live comes from the “oranges,” which are typically the S/L (switched live) terminals. The user separated the live for the pump from the oranges and connected a permanent live (perm live) to the boiler’s 230V terminal. The intention was for the perm live to supply the pump. The belief was that the boiler would automatically provide a perm live to the pump when needed.
Forum Responses and Suggestions
Forum members weighed in on the issue, offering valuable suggestions:
- Pump Over-run Function: Several forum contributors explained that boilers requiring pump over-run typically have dedicated terminals for connecting the pump. The pump over-run function is controlled by the boiler itself, ensuring that the pump continues running to dissipate heat from the heat exchanger even after the boiler shuts down.
- Direct Boiler Wiring: Members recommended taking a cable directly from the boiler to the pump. In this setup, the pump is solely controlled by the boiler, and its operation, including the pump over-run, is entirely managed by the boiler’s internal systems.
- Bypass Pipework: The importance of bypass pipework for pump over-run was highlighted. In cases where pump over-run is needed, bypass pipework is essential to dissipate the heat generated by the pump during the over-run period. The length and insulation of the bypass pipe may be specified by the manufacturer.
- Pump Over-run in S-Plan: A question regarding S-plan systems and the operation of pump over-run was raised. The discussion clarified that in S-plan systems, when the boiler shuts down, the valves are closed, and the water circulates through a bypass pipework to dissipate heat.
The Resolution
The original poster returned to the forum to provide an update on the situation. It was revealed that the issue had been resolved successfully. The solution lay in wiring the pump directly to the boiler, as recommended by several forum members. With the pump wired to the boiler, the boiler controlled the pump over-run function effectively.
The poster expressed gratitude for the advice and noted that both wiring configurations, while technically functional, worked. However, connecting the pump directly to the boiler ensured the correct operation of the pump over-run.
Conclusion
This forum discussion sheds light on common challenges faced when wiring a Worcester Bosch boiler into an existing heating system. It highlights the importance of correctly wiring the pump in systems requiring pump over-run, ensuring that the boiler controls the pump’s operation effectively. When encountering similar issues, it’s essential to seek advice and follow manufacturer-specific guidelines to achieve optimal boiler performance.
