Worcester Bosch Boiler EA 338 Fault Code
The Worcester fault code EA 338 low wter pressure Q & A or require an engineer for an emergency boiler repair.
The Worcester Boiler Fault Code EA 338 Error Common Q & A
Just below, we have a list of common questions relating to the EA 338 fault code on the Worcester Bosch Boiler.
- What does the EA 338 fault code mean on my Worcester boiler?
- Why does my boiler keep cutting out, and displaying the EA 338 fault code?
- What happens if the water pressure in my boiler is too low?
- How can I check if my water pressure is too low?
- When I reset my boiler, it works for a few minutes and then turns off, what is the problem?
- How do I fix the problem that’s causing the EA 338 fault code?
- How do I add pressure to my boiler?
- I’ve added pressure via the filling loop, and it’s now too high, what should I do?
- Now the boiler is showing the correct pressure, what should I do to clear the EA 338 fault code?
- My boiler is losing pressure after topping it up, what could be the problem?
- Where do leaks in a central heating system come from?
- How do I find the leak that’s causing the EA 338 fault code to occur on my Worcester boiler?
- There are small drops of water below my boiler, is this the problem?
- How can I determine if my PCB is subject to water damage?
- Will a boiler engineer be able to fix the PCB on my Worcester boiler?
- What else can cause low water pressure issues, and the EA 338 fault code to be displayed?
What does the EA 338 fault code mean on my Worcester boiler?
When a problem occurs with your boiler, it will lock out and display a fault code.
In this case, the EA 338 fault code means that the boiler can fire up, but is cutting out due to low water pressure.
Why does my boiler keep cutting out, and displaying the EA 338 fault code?
Your boiler has various sensors to determine that the operating conditions are correct for the appliance to fire. These include water and air pressure sensors.
In this case, it’s the water pressure sensor that has detected a problem. It’s found that the pump isn’t detecting water, or that the water pressure is too low.
What happens if the water pressure in my boiler is too low?
Most modern boilers will lock out when the water pressure drops below 1 bar. This is to stop internal boiler components from developing damage.
The most likely component that will be damaged by working with a low water pressure is the heat exchanger. If this overheats, there’s the possibility of it cracking. If this happens, a replacement could cost around £500.
The boiler locks out and displays the Worcester EA 338 fault code to stop this from happening, and to highlight the problem for your service engineer.
How can I check if my water pressure is too low?
Newer boilers will have a pressure gauge that’s easy to access. Typically, these will be built into the control/display panel on the front of the boiler.
This gauge will have red sections that are indicators of when water pressure is too high, or too low. Usually, anything below 1 bar or above 3 bar, will be in the red part of the gauge.
Most manufacturers will suggest that boilers are re-pressurised to 1.3 bar. Check your owner’s manual for the exact operating pressure for your boiler.
When I reset my boiler, it works for a few minutes and then turns off, what is the problem?
The problem here is that unless it’s an intermittent electrical malfunction, the cause of the EA 338 fault won’t be fixed by simply resetting the boiler.
Your Worcester boiler has a reset function that’s designed to be used after the problem is fixed. The boiler is locking out for a reason, in this case because it’s trying to avoid frying expensive internal boiler components.
Don’t reset your boiler until the problem has been rectified.
How do I fix the problem that’s causing the EA 338 fault code?
Most central heating systems will lose tiny amounts of pressure over a space of months/years. If this sounds like your heating system, then topping up the boiler pressure could be the answer.
However, if the boiler is losing pressure, getting topped up, and then losing pressure periodically after this, there’s a bigger problem at hand.
How do I add pressure to my boiler?
Pressure can be added to a boiler by adding water.
Worcester boilers have an external filling loop which allows water to be added. This is a small braided hose located below the boiler which should have a valve on it.
As you open this valve, water will be added to the central heating system, and the pressure will increase.
If you’ve not topped up pressure on a boiler before, it’s worth going steady, as you don’t want to over pressurise your boiler.
I’ve added pressure via the filling loop, and it’s now too high, what should I do?
It’s not good to have a boiler that’s above its operating pressure.
So first of all, if it’s above 2 bar, you should switch off your appliance.
As a boiler heats up pressure will increase, and any additional pressure is going to put unwanted strain on components such as the pump, and potentially cause damage.
Now the boiler is off, you’ll need to bleed water from the system.
To do this, you’ll need a container/bucket to catch water, towels to protect walls/flooring, and a specifically designed radiator bleed key.
Each radiator has a small bleed valve on the top-side of the rad. Slowly open this valve. As you do, you’ll notice a hissing noise (this is air escaping, and nothing to worry about).
When the hissing noise stops, you’ll start to see water being released. It’s a good idea to have someone checking the boiler’s pressure gauge, to determine when the boiler drops to the optimum pressure.
Once the boiler is set at the correct pressure, close the valve, dry around the valve, and check it in a few minutes to ensure it’s not leaking.
Now the boiler is showing the correct pressure, what should I do to clear the EA 338 fault code?
If your Worcester boiler is now showing the correct pressure (1.3 bar, or the pressure recommended by your owner’s manual), the boiler can be reset.
Before resetting the boiler, it’s worth leaving the appliance for 10-15 minutes.
Central heating systems will lose pressure fastest, when pressure is highest.
So, if you see pressure decreasing over the next few minutes, there’s another problem that needs to be fixed by a boiler engineer.
My boiler is losing pressure after topping it up, what could be the problem?
The most widespread problem we see with central heating system, is leaks.
Sometimes they’re not visible, and that leads people to believe they don’t have one.
Where do leaks in a central heating system come from?
Every part in your boiler and throughout your central heating system is a potential culprit. So, that includes:
- Pin holes in towel rails and radiators
- Weak copper joints
- Blown seals on a boiler’s pump
- A crack in the heat exchanger
- Leaking radiator valves
Many of these leaks are easy to spot, such as a leak from a radiator valve. However, there are others that are not so easy to pin-point.
For instance, if you have a minimalist bathroom design whereby the pipe work for radiators is chased into the wall and boarded/tiled over, it’s going to be hard to pin-point whether that is the source of the leak.
How do I find the leak that’s causing the EA 338 fault code to occur on my Worcester boiler?
First, you’ll want to check that there’s no water leaking from your boiler. If there is, there’s a good chance that it’s coming from the heat exchanger or pump.
Next, you’ll need to examine each towel rail, radiator, valve and section of pipework individually. If there is a sign of water, that needs to be fixed.
Finally, if you can’t spot a leak, look for walls that have sections of pipe going through them.
Can you see signs of moisture on the walls?
If there is, that’s a signal of a pin-hole in weakened copper pipe, or a copper joint that needs re-soldering.
There are small drops of water below my boiler, is this the problem?
The biggest problem here isn’t the leak, as a boiler engineer will be able to remove the boiler’s casing to find and fix it.
The problem is, how long has it been going on, and has it caused any other damage?
Modern boilers are full of electrical components. Among those, is the PCB (printed circuit board).
This is the heart of any boiler, as it receives and gives signals to all other electrical components.
These include the:
- Pump
- Fan
- Gas valve
- Flame sensor
- Air pressure switch
The last thing you want, is for moisture to make its way into the PCB. Directly dripping onto the PCB can be fatal, completely ruin it and lead to a replacement.
However, any leak in a boiler can be fatal. The internal temperature of the boiler can produce condensation, and this condensation makes its way into all boiler parts.
How can I determine if my PCB is subject to water damage?
If you have a Worcester boiler with water damage, you’ll have noticed it acting strangely.
As damage increases, it will malfunction. So, it might start giving and receiving incorrect signals to boiler parts. This could lead to many issues including:
- The wrong fault codes being displayed
- It turns on and off randomly
- The heating doesn’t get to temperature
- Hot water works, but heating doesn’t (and vice-versa)
Another sign of water damage is going to be a control panel’s LED lights come on sporadically.
Will a boiler engineer be able to fix the PCB on my Worcester boiler?
Minor faults can be fixed. For example, loose connections can be re-secured.
However, water damage is rarely something that can be fixed with a simple repair.
If the PCB is broken, a replacement will be needed. They’re available from local plumbing merchants, but the cost including installation can be £500 and beyond.
What else can cause low water pressure issues, and the EA 338 fault code to be displayed?
If there’s still a low-pressure issue after finding and fixing a heating system leak, your boiler engineer is going to be looking for two things.
First, the water pressure sensor needs to be tested. If this is faulty, it’s likely to be obvious. The gauge will be showing a pressure that’s within operating range (above 1 bar), but the pressure sensor is getting a signal that it’s below this pressure and lock out the boiler.
If this is the case, replacing the sensor will fix the problem.
Secondly, they’ll be looking at the pressure release valve and expansion vessel. These components are designed to release system pressure when it gets too high.
However, if they activate before they should, this is going to lead to a pressure being lost before it should, and that’s a pressure that the boiler isn’t able to operate with.
Other Worcester boiler issues
More more boiler issue regarding the Worcester Bosch the please visit the Worcester Boiler Problems And Cures page.