Baxi 836 Problems

The Baxi 836 is a popular combi boiler that many households rely on for their heating needs. However, like any piece of machinery, it can present some challenges. One such problem that users have reported is the boiler continuing to fire even when there isn’t a demand for heat. Let’s delve into the issue and discuss potential solutions.

Problem: A Baxi 836 combi boiler user noticed that despite the zone valves indicating no demand for heat (an open circuit), the boiler continues to operate. If the wire to the boiler is disconnected, it stops.

Temporary Solution: To ensure that the house remains warm, a temporary measure was implemented. The valves were held open, and the call for heat was directly derived from the time clock. This solution provided heat but is not a permanent fix.

Possible Solutions:

1. Consult the Installer: The first step in addressing any installation-related problem should always be to consult with the installer. However, in this case, the installer believed that the wiring was correct and usually only deals with wireless stats. For more intricate electrical works, they would employ an electrician.
2. Using a Relay: After some troubleshooting, a successful solution was found. A 230v relay was wired using the orange and grey contacts on the zone valves. A clean closing contact was then taken off the relay to the boiler. This arrangement worked perfectly.The boiler does not truly have a dry volt-free closing contact. Instead, there are two contacts with 230v present on one of them. When this contact is shorted to the other, the boiler fires up. It seems there may be some minor voltage anomalies, potentially caused by the way the system is wired, or interference from other devices, which might be enough to mislead the boiler into thinking it needs to run.

Conclusion:

While the Baxi 836 combi boiler is efficient and generally reliable, it’s not immune to issues. Wiring and electrical complexities can occasionally present challenges. If you’re facing similar problems, it’s advisable to seek guidance from a professional or someone familiar with the workings of the particular boiler model.

Remember, while temporary solutions might address the immediate need, it’s crucial to identify and solve the root cause of the problem for long-term efficiency and safety. In this case, introducing a relay between the zone valves and the boiler appeared to resolve the issue, ensuring that the boiler only fires when genuinely needed.