Worcester Greenstar E9 fault, diagnostics, and Ideal Logic2 Max installation

1st Feb, 2023 | Heating
Diagnosing the old boiler

A customer of ours contacted us to advise they had heating but no hot water from their Worcester Greenstar, and no-fault code was showing.

We initially advised over the phone that this could potentially be a blocked plate-to-plate heat exchanger or a stuck diverter valve which they can help diagnose if competent. This gentleman is a chemical engineer, so can more than hold his own.

We advised the client to run the hot tap and watch the temperature on the LCD screen on the front of the boiler to see if this rises rapidly; it was a slow rise which is not common with a blocked plate. We then asked the client to feel the flow pipe to see if this heated up which would indicate the diverter was stuck and the water was flowing around the heating system; however, it didn’t.

With the hot tap still running for a long period of time and conducting the basic checks we advised above; the boiler eventually went to lockout showing an E9 fault code. We then advised the client that we would need to attend site to investigate further.

Boiler checks

When attending site, we take the necessary steps which is a process of elimination. We started with a visual inspection and basic safety checks, before getting the boiler into fault state where we looked at the manufacturer’s instructions which advises to check the following:

Check fuse on the PCB – it couldn’t be this as there was power to the boiler.

Check system pressure – this was 1.5 bar which is recommend, along with the central heating being operational.

Check pump operation – the radiators were getting hot, so we knew the pump was circulating around the heating system.

Bleed appliance – we bled the boiler and radiators to make sure there was no trapped air or air in the system.

Check safety temperature limiter – this helped us identify the fault.

An E9 fault means the safety temperature limiter in the central heating flow pipe has tripped to prevent the boiler from overheating and potentially causing an explosion. The temperature sensor on this particular Worcester Greenstar boiler is in a dry pocket, some sensors are in wet pockets which means you have to drain the boiler before your remove the sensor.

After isolation of the appliance and checking all the electrical connections and harness we knew there was no damage to these, nor was there any water damage as inside the boiler was dry. We removed the sensor from the central heating flow pipe to see if it would shut off without showing an E9 fault, which would indicate a partially blocked heat exchanger. To allow us to check the fault more quickly without running the hot tap, we put the boiler into service mode which makes the boiler operate at its maximum capacity to prove the boiler can operate safely. After a very short period, the boiler locked out as the sensor reached 105 degrees, then shutting the boiler off without any fault code showing as the sensor was removed from the dry pocket on the flow pipe. This is how we proved the heat exchanger was the problem.


The next steps

We contacted Worcester technical for peace of mind, of any further checks we could or should do. They advised the boiler would be beyond economical repair and advised we recommend a replacement to the client.
During the inspection of the boiler, it was clear the boiler had not been serviced or looked after, some of the signs were as follows:

 – Site glass to the burner has not been upgraded.

 – Full condense.

 – Poor water quality.

 – No magnetic filter for ongoing system protection.

 – No electrolytic filter to help with hard water areas.

 – Expansion vessel had lost charge.

These are just some of the tell-tale signs that the boiler has not been looked after. We actually find it amazing that it is not legislation to have your gas burning appliances serviced in every household given the devastation they can cause should there be an explosion.

It is mandatory that cars should have an MOT, however it is not for boilers to have a service/safety check, which in most cases can cause as much devastation to property and life if they are not maintained correctly, however that is another discussion altogether.

While it is never a pleasurable experience to advise a client that their appliance will need replacing, it is part and parcel of your duty of care to make sure that the client is safe after your inspection.
We find that if you explain the details of your diagnostic in a way people can understand then they are receptive. We gave the client an estimate for the works which was accepted and fortunately the client did not have to stay in the property while we sourced the necessary materials to undertake the works.

When we attended site this upgrade had its benefits, we knew we could give the system a cleanse without replacing the boiler first as the boiler would operate in central heating mode. Here is a link to a previous blog on a MagnaCleanse https://warnersinnovations.co.uk/how-to-combat-rising-gas-prices/ we also have some content in our YouTube video below if you are a visual person.

After giving the system a cleanse, we drained down and got the new boiler on the wall. This was the Ideal Logic 2 Max which has only recently been brought to market. While we personally didn’t think there was much wrong with the original Logic Max for the price, it seems there had been a few modifications like relocating the PRV and condense, updating the LCD interface and settings and making the front panel more aesthetically pleasing.

Installing the new boiler

I must admit the interface is a welcomed update with the ability to go up/down and back/forwards, this is certainly more user friendly. I am not particularly sold on the relocation of the PRV and condense as trying to combine them into a hotun, while being supported as we like to do was challenging. We also like to terminate them into an internal drain where possible to prevent the condense from freezing in extreme conditions.

We like to make sure the boiler is protected, along with running as efficiently as practically possible. Here are some of the products we incorporated on this installation.

 – Halo RF programable room thermostat – this smart thermostat is a welcome addition to any Ideal boiler. The simple installation process due to no wiring makes this a stress-free installation while making sure your boiler is boiler plus compliant.

 – Ideal magnetic filter– usually located on the return pipe to help protect the boiler and system from any potential magnetite build up through poor water quality. Having this installed allows you to easily check the water quality on an annual service.

 – Mini shock arrestor – this prevents water hammer and damage to the internal boiler parts.

 – Electrolytic filter – helps break down the irons in the water.

Looking after your new boiler

After commissioning the appliance as per manufacturer’s instructions, we like to talk to the client to find out their needs and how to best set up the system to be operating as efficiently as possible for them. We find most people have their settings at maximum either left like this initially from the original installation or the potentiometers have been turned to maximum to give them hotter water and heating without thinking about the pros and cons.

We advise that the hot water setting is no higher than 50-55 degrees depending on how far this needs to travel as you will inevitably get some heat loss. However, you will find in most cases people mix their hot water with cold as it is too hot. We will explain why this is not beneficial after discussing the central heating.

We advise under new regulations of part L of the building regulations that the flow temperature on your boiler should be 55 degrees. This is to allow the return temperature to be lower allowing your boiler to condense. If your condensing boiler is not condensing, then it is not realistically doing the job it was designed and manufactured for.

While you will receive financial benefits to your boiler running more efficiently, such as the boiler condensing using the latent heat and less in gas consumption; your radiators and home will take longer to heat up which is just something to bear in mind.

Having your hot water or heating set to a temperature you don’t need will only increase running costs, which is something we are all conscious about today.

If you would like any further information, please do not hesitate to contact a member of our team:

01636 551555


Here is the journey of the boiler installation on youtube: