PulsaCoil A Class Common Faults

Here you will find a selection of PulsaCoil A Class Common Faults, by following these simple steps you may be able to repair your thermal store without the need for an engineer to attend.

Although many users might assume that a PulsaCoil A Class 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. Sensor failure or relay fault – a fault with a sensor will disable the relay, cutting off power supply to the two immersion elements inside the PulsaCoil A Class system. As relays control the supply to both immersion elements, it won’t allow power to the immersion element if faulty.

3. Immersion elements – because there are two immersion elements, it is very rare that both will be faulty or fail at the same time. If both of your immersion elements 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. PCB board failure – if the PCB board 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 require, you may find there is a fault with one of the sensors, or a build-up of calcium in the plate heat exchange. The sensors connect to the PCB board, and if faulty will not power the PulsaCoil A Class pump. A build-up of calcium will result in the plate 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 do have hot water when using the ‘On Peak’ boost

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 thermal store 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 thermal store will not be heated up correctly

3. Fault with the ‘Off Peak’ element – a faulty immersion element will not heat up water inside a thermal store overnight, resulting in a lack of hot water the next day

4. Faulty relays – when relays become faulty it prevents the supply of power to an immersion element. The immersion element is vital for heating the water inside the thermal store 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 the thermal store

4. Fault with the booster immersion element relay – when the relay becomes faulty it prevents the supply of power to an immersion element. The immersion element is vital for heating the water inside the thermal store.

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. Internal cylinder leaking


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 complex 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 relays – 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 PCB board – most inexperienced engineers believe if the pump is working, and a continuity/ buzz test has been successful, that the PCB board 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. Improperly applied heat sink compound – if heat sink compound is applied to sensors, 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 Plumbing Group. 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 specialise only in the service and repair of PulsaCoil thermal stores.

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.

If the red LED is flashing and you are unable to receive hot water, an engineer will be required.

PulsaCoil A Class Common Faults – Self-help video

Some PulsaCoil A Class problems don’t require a professional repair and can be solved quickly and safely by you.

Please note that these hints and tips are provided for your interest and ease of reference only. We cannot accept any responsibility for any advice or information contained within our videos. If you are in doubt about how to fix a problem with your PulsaCoil A Class, you should always book a repair by a qualified repair engineer.

This Video on the PulsaCoil A Class thermal store shows the basic principles of operation including refilling the system.

After checking the PulsaCoil A Class common faults, if you are still having an issue with your thermal store please do not hesitate to contact our office staff who can talk you through our repair options. Please call 0800 02 365 92.