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PulsaCoil 2000 Common Faults

PulsaCoil 2000 Common Faults

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PulsaCoil 2000 Common Faults

If you have a technical query about your PulsaCoil 2000 thermal store, boiler or water heating system, a variety of technical support is available for tenants and homeowners.

Helpful video – Fix The PulsaCoil 2000 Yourself

Some Gledhill PulsaCoil 2000 problems don’t require 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 Gledhill PulsaCoil 2000, you should always book a repair by a qualified repair engineer.

This Video on the Gledhill PulsaCoil 2000 thermal store shows the basic principles of operation including refilling the system.


If all else fails, give us a call! Our householder technical support team can answer your queries and offer expert advice about your Gledhill PulsaCoil 2000 thermal store, boiler, or water heating system. We’re available 5 days a week, excluding bank holidays, between 9 am and 5 pm Monday to Friday.

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 with the PulsaCoil 2000 and how you can identify them yourself.

PulsaCoil 2000 no hot water

If you are experiencing a lack of hot water or an erratic supply of hot water, it will usually be for one of four reasons:

  1. Lack of water in the thermal store. This is generally the result of evaporation or a leak in either the internal thermal cylinder or immersion heater. If the thermostat has locked open, this can lead to steaming or ‘kettling’ of the system, causing water to evaporate internally in the cylinder, and resulting in a lack of hot water at the tap outlets. You can check your hot water levels yourself using our DIY video as a guide (link).
  2. Failure of the immersion heater element or thermostat. Failure in either of these components will prevent the system from heating up, resulting in a lack of hot water.
  3. Delivery system failure. An issue with the sensor, pump, printed circuit board, or plate heat exchanger can affect the delivery system. Even if the internal thermal store heats up successfully, if any of these components fail, the delivery system will not send hot water to your tap outlets.
  4. Failure of the external economy-seven time clock. This can prevent the ‘off peak’ immersion from heating overnight, leaving the internal cylinder cold.

Further items causing your Pulsacoil 2000 to have no hot water can be found here.

PulsaCoil 2000 is cold to touch

If your thermal store is cold, it will likely be for one of four reasons:

    1. Immersion heater thermostat tripped – this can be reset manually by an electrically competent person
    2. External economy seven-time clock failure – this can prevent the off-peak immersion from heating and would need testing by a qualified engineer
    3. Immersion heater thermostat or element* failure – both will need to be tested by a qualified engineer

*PulsaCoil 2000 uses a 3kw, 14inch Incoloy Immersion heater element, operating through an 11inch rod thermostat which has a separate safety overheat manual reset cut-out.

PulsaCoil 2000 red fault light is illuminated or the green light has disappeared

Your PulsaCoil 2000 is equipped with a Printed Circuit Board which automatically monitors the system to ensure that it operates most efficiently. When the red fault light is illuminated, or the green light disappears (link below), it means the system has overheated and a resetting by a service engineer will be required.

There are two options for dealing with a red light fault:

      1. Reset the ‘manual safety overheat reset button’ yourself by removing the front cover. This will only work for a short period of time, as it causes the PulsaCoil 2000 to continually overheat, tripping the ‘manual safety overheat reset switch’ and killing all power to the unit.
      2. Call an engineer. We can come out and remove the ‘manual safety overheat reset button’ and the ‘On & Off Peak’ immersion thermostats. Both can be replaced with the new retrofit immersion heater thermostats, incorporating separate overheat safety cut-out switches.

If you find that the green light on your PulsaCoil 2000 has disappeared, but you still have hot water, it may be that the green light has simply failed. You can remove the front cover and check the Printed Circuit Board. The small red led should be flashing twice per second. If this is not the case, or if the red fault light has been illuminated, call a service engineer.

PulsaCoil 2000 is leaking

If your PulsaCoil 2000 is leaking or continually losing water from the header tank, this could be for one of three reasons:

  1. The immersion is leaking. This is a replaceable part which would involve
    draining down the internal cylinder
  2. Leaking pipework. Generally, if the leak is external to the cylinder then this is repairable, either by tightening or replacing damaged pipework or fittings.
  3. Leaking Cylinder. Unfortunately, this would mean your PulsaCoil 2000 is beyond economical repair and you require a replacement boiler.

Your time clock is not set up correctly

The PulsaCoil 2000 can either be installed on a traditional off-peak system controlled via the electricity meter or via an external time clock. Time Clocks installed on PulsaCoil 2000s are all installed aftermarket and are not warranted or included in PulsaCoil 2000 policies.

Know how to set your time clock correctly:
      • Economy seven timings are generally set around 12:00 through until 7:00 am
      • Economy ten timings are generally set around 12:00 through until 7:00 am as per economy seven and then an additional top-up between 15.00 and 17:00 pm

Need a new time clock? PulsaCoil Group can install one.

Inexperienced engineer mistakes and misdiagnoses

As the PulsaCoil 2000 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 elements – 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


  1. 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


  1. 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


  1. 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


  1. 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.


  1. 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


  1. Failing to check the supply – this may sound simple but ‘Off Peak’ supplies only come on at night, so different types of tests 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 distributor’s responsibility.

PulsaCoil 2000 boilers are backed by our comprehensive PulsaCoil Group after-sales service, providing service and support for PulsaCoil 2000 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.

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Our Technical Support team can answer technical queries and offer expert advice about our Gledhill PulsaCoil 2000 thermal store, boiler, or water heating system. Search the forum with your query to see if a solution has already been posted. If you can’t find what you’re looking for, simply post your own question and we’ll respond as soon as we can.

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