Mira Vortex Waste Problems

Shower drainage problems are not uncommon, but they can be particularly bothersome if not addressed in time. One of these issues has emerged with certain Mira Vortex waste installations, especially in showers that experience high flow rates. Here, we will delve into the problem and look at potential solutions.

The Problem: A Mira Atom thermostatic mixer shower was installed, running off a 35kw combi boiler, and produced a powerful flow. However, the challenge lay in the shower waste’s inability to keep up with this flow. As a result, the shower tray would fill up almost to the brink of overflowing. An intriguing observation was that the waste flowed faster when there was more water in the tray, creating a cyclical effect where the tray filled up and emptied in intervals.

The waste system in question has a 50 litres per minute flow rate. However, there’s a catch – this rate was tested at 120mm head, which is higher than the height of the shower tray. This raised concerns about whether the height discrepancy was the root of the drainage issue.

Potential Causes:

1. Faulty Gradient of the Waste Pipe: One possibility is that the 40mm waste pipe might not have the correct fall, meaning it could be running slightly uphill or there might be an obstruction where it connects to the soil stack or within the waste pipe itself. A waste pipe that is too level or has insufficient fall will not drain efficiently.
2. Tilers Mess or Blockages: There could be obstructions in the waste system. It was noted that after pouring jugs of warm water directly down the drain, the drainage problem appeared to rectify itself temporarily. This could mean an airlock was broken or there was tiling residue blocking the drain. Furthermore, there’s a possibility of blockages, especially in complex pipe configurations, which can be difficult to clear without using potent cleaning agents.
3. Ventilation Issues: The waste problem might also stem from air trying to escape from the shower waste while water is flowing in. This creates a cushion of air that obstructs the wastewater. It’s analogous to the ‘glug-glug’ action when trying to pour water out of a full container too quickly.
4. Installation Concerns: The expertise of the installer has come into question. The configuration and design of the waste system, the type of trap used, and the fall of the waste pipe are all critical factors in ensuring efficient drainage.

Potential Solutions:

1. Reevaluate Waste Pipe Gradient: Ensuring that the waste pipe has the correct gradient is crucial. If it’s too level or running uphill, it will need to be adjusted.
2. Clear Blockages: Regularly check for and clear any obstructions in the waste system. Be particularly vigilant about hair or debris that might accumulate in the shower trap.
3. Vent the Soil Stack: Changing the current configuration to a fully vented stack that extends above the roof can help alleviate air pressure issues in the drainage system.
4. Reevaluate Installation: If the drainage problem persists, it might be necessary to consult a different plumber or expert to assess the installation and recommend changes. It’s important to choose a waste system compatible with the shower tray and ensure that it’s installed correctly.

In conclusion, while the Mira Vortex waste problem might be bothersome, understanding the potential causes can guide homeowners towards the right solution. Proper installation, regular maintenance, and addressing issues promptly can ensure a hassle-free shower experience.