While thermal store hot water heaters do not suffer from the same problems found with unvented hot water heaters, they are susceptible to a number of problems that might cause the need for professional repairs or service. In particular, they are prone to problems with the electrical supply, as well as faults in the thermostat and immersion heater. While some of these issues can be handled by the average homeowner, others will require the assistance of a professional EasyFlow technician. Below, we’ve detailed some of the more common thermal store faults that you might experience.

In order to ensure a safe temperature at the taps, thermal store hot water heaters use a blending valve to mix hot water with cold water from the mains prior to sending it to the taps. Not only does this help prevent scalding (as required by G3 building regulations), but it also serves to enhance the capacity of the system, allowing a smaller hot water heater to provide a greater volume of hot water than what the cylinder could hold.

Of course, blending valves are subject to wear and tear, and will eventually fail. As they deteriorate, you will notice the water temperature at the taps steadily declining. Eventually, no hot water will be available. To check if the blending valve is the culprit, you can do a couple of things:

• Check the Tank: Check the brass boss located where the immersion heater in the tank is installed to see if the water is actually hot. If it is not, your problem isn‘t with the blending valve. If it is, move to the next step.
• Adjust the Valve: Turn the blending valve to the minimum setting. Check the temperature of the hot and cold inlet pipes and ensure that there is a large difference between the hot and cold pipes. Note that the water from the tap should feel similar to the cold inlet pipe.
• Adjust the Valve Again: Now, turn the valve to its maximum. The outlet temperature should rise to about 55 degrees centigrade if the blending valve is working. If it does not, then the valve needs to be replaced.

Thermal store systems can use one of two types of heat exchanger – some use a coil wound through the centre of the cylinder, while others use a plate heat exchanger. In plate type systems, the passageways within the exchanger can become clogged with debris (rust, dirt, sand/sediment, and lime scale). When this happens, water cannot move through the exchanger, which means heat from the hot water heater cannot be moved to the main water line, and it will run cold at the taps. The symptoms are similar to what happens if the blending valve begins to malfunction, but the underlying problem is very different. In this instance, you’ll need to service the plate heat exchanger, which is not something that you should attempt on your own. Call EasyFlow today.

In many thermal store systems, a pump has been added to force water through the heat exchanger. Water moves upward, out the top of the cylinder, and is then pumped back into the cylinder at the bottom, where it goes through a series of baffles to prevent it from coming in contact with cold water stores. Like all other components, pumps will eventually wear out and fail. The only recourse in this situation is to have a professional EasyFlow technician replace the failed pump.

While thermal store systems don’t suffer the same issues as unvented systems, they are still tied to the electric lines. This means that any leaks, regardless of size or location, are serious concerns. It is absolutely essential that you call an EasyFlow engineer if you notice any leaks from the thermal store.

At EasyFlow, we offer repairs and service for thermal store systems. Call today at 0800 433 4043 or use the convenient form below to get in touch. EasyFlow is a Country and Town Limited Service and we provide services throughout Manchester, Liverpool and Chester and the surrounding areas.

If you need assistance with any hot water heater repairs, to schedule hot water heater maintenance, or to install a new hot water heater, call EasyFlow at 0800 433 4043