Although many users might assume that a PulsaCoil 2000 thermal store is the same as a conventional hot water cylinder, the only similarity in fact is that they both hold hot water and are heated via immersion heaters. In every other respect, the two are vastly different systems. As such, we have outlined some common faults specific to the PulsaCoil A Class and how you can identify them yourself.
If you are experiencing a lack of hot water, there is likely to be an issue connect with the immersion elements, which heat up the water inside the tank.
1. Electricity supply fault – if there is no electricity to your PulsaCoil A Class system, the PSC (pump speed control), immersion elements, and other internal components of the system will stop working, and the water cannot heat up.
2. Main thermostat or relay fault – a fault with the main thermostat will disable the relay, cutting off power supply to the two immersion elements inside the PulsaCoil A Class system. As the relay controls the supply to both immersion elements, it won’t allow power to either immersion element thermostats or immersion elements if faulty.
3. Immersion elements or immersion element thermostats fault – because there are two immersion elements, and a thermostat for each, it is very rare that both will be faulty or cut-out at the same time. If both of your immersion elements or immersion element thermostats have failed, it is likely that one has been faulty for some time, but has gone unnoticed as the second had acted as a back-up in supplying hot water.
4. PSC (pump speed control) or store sensor failure – if the pump speed control or store sensor is not working correctly, the PulsaCoil A Class pump cannot be supplied with power, and no hot water can be pumped through the system.
5. Hot water sensor failure – this sensor instructs the PSC (pump speed control) to send the correct power supply to the pump, pumping hot water around the installation. If faulty, this instruction will not be sent.
If you have some hot water, but not as much as you need, you may find there is a fault with the hot water sensor, or a build-up of calcium in the pleated heat exchange. The hot water sensor connects to the PSC (pump speed control), and if faulty will not power the PulsaCoil A Class pump. A build-up of calcium will result in the plated heat exchanger failing to exchange hot water. If either of these problems occur, hot water cannot be pumped around the system.
I have no hot water when using ‘Off Peak’ but using the booster works
1. Fault with the ‘Off Peak’ supply – If no supply is fed through to the ‘Off Peak’ immersion element, it cannot heat the water inside the storage tank overnight
2. Fault with the ‘Off Peak’ switched fused spur – spurs are an isolation point for supplies to immersion elements. If a spur becomes faulty, there will be no supply to the immersion element and the water inside the tank will not be heated up correctly
3. Fault with the ‘Off Peak’ element – a faulty immersion element will not heat up water inside a storage tank overnight, resulting in a lack of hot water the next day
4. Fault with the ‘Off Peak’ immersion element thermostat – when the thermostat becomes faulty it prevents the supply of power to an immersion element. The immersion element is vital for heating the water inside the storage tank overnight
5. Damage to the ‘Off Peak’ cables – damaged cables can stop the supply of power to ‘Off Peak’ immersion elements. They can also become a fire hazard so will need urgent repair.
1. Fault with the Booster supply – if no supply is being fed to the booster immersion element, it cannot begin heating the water inside the storage tank
2. Fault with the booster switched fused spur – spurs are an isolation point for supplies to immersion elements. If a spur becomes faulty, there will be no supply from the booster and the water inside the tank will not be heated up correctly
3. Fault with the booster immersion element – a faulty immersion element will not heat up water inside a storage tank on demand
4. Fault with the booster immersion element thermostat – when the thermostat becomes faulty it prevents the supply of power to an immersion element. The immersion element is vital for heating the water inside the storage tank instantaneously
5. Damage to the booster cables – damaged cables can stop the supply of power to booster immersion elements. They can also become a fire hazard so will need urgent repair
1. Immersion thermostat pocket leaking
2. Thermal storage tank inside system rusted
3. Pipe work rusted
4. Pipe burst
5. Sensor dry pocket failed
All of these problems occur due to wear and tear. It is usual for the original immersion element inside a PulsaCoil A Class pocket to start leaking.
As the PulsaCoil A Class is a unique thermal store, there are a few common mistakes made by engineers inexperienced in installing and repairing this tricky system.
1. Incorrect testing of immersion element – we often find that a simple continuity buzzer has been used to check immersion elements. This is problematic, as even a faulty immersion element can show a closed circuit. An ohms resistance is required to establish if an immersion element is faulty
2. Checking the pump incorrectly – a certain voltage is required for a PulsaCoil A Class pump. If this voltage is showing and the engineer is still not getting hot water, he could be wrong in diagnosing a fault in the pump. This should be correctly inspected in other ways to ensure that it is in fact the pump that is faulty
3. Not knowing how to properly test the relay – just because the relay is not allowing power to pass does not mean it is faulty. The relay is connected to other components that tell it to switch on or off. This can be inspected by bypassing a component safely
4. Diagnosing a faulty PSC – most inexperienced engineers believe if the pump is working, and a continuity/ buzz test has been successful, that the PSC must be faulty. However, in the PulsaCoil A Class this is not always the case, and certain further tests must be undertaken prior to diagnosing a fault. As this is the most expensive part second to the entire system
5. Not resetting thermostats – some engineers believe if a thermostat is not showing continuity it must be faulty. This is not always true, sometimes a simple reset can fix the problem. Resetting the thermostat is simple if you know what you are doing, but can be difficult and extremely hazardous if you don’t. If the problem persists then we would recommend changing it.
6. Improperly applied heat sink compound – if the heat sink compound is not applied to the correct sensor, it will give you a fluctuation in temperature, or no hot water at all. It is vital that the engineer applies it to the correct sensor
7. Failing to check the supply – this may sound simple but ‘Off Peak’ supplies only come on at night, so different types of test will have to be performed in lieu of a standard voltage test. This can save you money as the ‘Off Peak’ supply is your network distributors responsibility.
PulsaCoil A Class boilers are backed by our comprehensive Hot Water Cyllinders Ltd. after-sales service, providing service and support for PulsaCoil A Class products all year round. Our Engineers have an exceptional understanding of the Pulsacoil range of hot water solutions because we specialize only in the service and repair of PulsaCoil products.
All parts and spares required for your PulsaCoil A Class are available please visit our spares page.
On the front of the PulsaCoil A Class boiler control panel is a red LED indicator. Next to the LED is a label which states "Fault attention required" if flashing.
On some of the original models of the PulsaCoil A Class this flashing light can simply mean that the internal temperature has cooled below the factory preset and you are able to reheat it using the on peak boost function, by pressing the black 'On Peak Boost button' on the front of the unit, this can occur even when there is no fault.
There is no requirement to use the on peak boost, unless additional hot water is required. The unit will re-heat automatically during the off peak cycle.