Though normally very sturdy, occasionally your mixer shower might develop a fault. Here are some of the most common issues we get asked by our customers.


Mixer showers are one of the most prominent showers found across the UK today, being installed in homes and hotels nationwide.


These showers are considered to be very reliable, and new models by some manufacturers are automatically covered with as much as 5-year guarantees (as opposed to only 1-2 years standard for electric showers).


Mixers use separate hot and cold water supplies, and blend both to provide the water at the temperature you demand from it. A cartridge inside the shower regulates the temperature as desired, and come in either manual or thermostatic varieties. They can be installed on gravity fed systems (where the water is taken from hot and cold tanks), combination boilers, or on a pump (which also takes water from hot and cold tanks). A homeowner favourite is the Mira Excel EV.


Our 2-minute video below neatly sums up the main issues with mixer valves. Or you can read the transcript underneath.



The most common faults with mixer showers are:


  • Intermittently running hot and cold. From our experience, this occurs mostly on combination boiler setups. The usual suspects for this problem are a blocked shower head, kinked or damaged shower hose, or blocked inlet filters in the shower itself. It could also be due to faulty non-return valves.
  • Permanently running either hot or cold. Blocked inlet filters and faulty non-return valves can also cause the shower to either run constantly hot or cold, despite your efforts to adjust the temperature. If either of these suggestions don't work at correcting this problem, a new thermostatic cartridge – essentially the heart of a mixer shower – will be needed. This will almost certainly fix the issue, but occasionally the cost of a new cartridge may exceed the value of a new shower, so it's worth bearing in mind.
  • Water dripping out of the shower head when the shower is off. This is a fairly frequent complaint with mixer showers that we receive. Depending on the exact model of your shower, the problem could be deduced down to: new seals being required; new flow cartridge, if supported by your mixer; or a new thermostatic cartridge, as explained above.
  • Noticeably reduced water flow rate. Similar to undesired temperature changes mid-shower, this common problem can also be caused by a blocked shower head, kinked or damaged shower hose, or blocked inlet filters in the shower itself. If installed, blocked filters on a pump may also be the issue, which prevents the pump from boosting the water supply up to the shower, and defeating the object of the pump's purpose.            


            Common problems with mixer showers image 1 - Blocked filters can be a problem with mixer showers, but cleaning them should help to sort the problem.
Blocked filters can be a problem with mixer showers, but cleaning them should help to sort the problem.


The following solutions should help to remedy the problems mentioned above:


  • Blocked shower heads. A build-up of limescale and debris on the nozzles or inside the shower head can cause blockages, preventing water from exiting through the head properly. Simply clean the shower head using a descaler or replace it.
  • Kinked or damaged shower hoses. Unfortunately, a shower hose that has been sufficiently damaged or kinked (including internal collapse or stretching) will need to be replaced and cannot be fixed.
  • Blocked inlet filters. These can usually be removed from the shower (please consult your shower's manual) for a gentle clean, before being reinserted. Failing that, new inlet filters will need to be purchased.
  • Faulty non-return valves. Non-return valves that are faulty will need to be replaced, as damaged valves will not be performing their job optimally or at all, which can cause damage to the shower.
  • Faulty seals / flow cartridge / temperature cartridge. Cartridges, both flow and temperature, as well as seals, will need to be purchased and installed to rectify faulty editions in the shower currently.       


Always ensure all instructions are followed from the manufacturer or consult a trained plumber when performing some of these item replacements.