Glow Worm Ultracom (1) 30CXI F9 Fault Possible Cheap Fix

[Georgeyboy18]

Evening all,

I had the dreaded happen during the week... Yes the boiler came up with an F9 fault and wouldn't do anything. Just what you don't need with temperatures of -6

With this boiler the F9 fault represents a pressure issue so first things first
1) Check the pressure on the boiler (1.5 bar is about right on these)
2) If pressure is fine its time to take the cover off and check the pump
3) If the pump appears to be working fine then chances are its a faulty water pressure sensor!

Before you panic this is NOT a major issue or a major deal to repair at all and worst case scenario (with this model) it will cost you £25 for a new sensor and you can easily replace this yourself!

The most annoying problem with this fault I found was finding the correct sensor. The sensor itself had the part code 0020016532 stamped on it. According to Glow Worm technical this sensor does not even exist! The actual sensor you will need (if you have to replace it) has the part code 0020014190.

BEFORE you buy a new sensor I strongly suggest you remove the existing one and simply clean it as when I removed mine it was completely clogged up like this

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• Georgeyboy18
• 11 Feb 2012
• 1

and once cleaned out carefully with a small screwdriver and cotton buds it should look like this

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• Georgeyboy18
• 11 Feb 2012
• 1

To replace the sensor turn off the power and:

1) Close the valves on the central heating flow and return pipes (these being the 2 largest pipes usually)
2) On the left hand valve there is a drain. Simply attach a hose or stick a decent size bowl under the drain and open it to drain the boiler. Once drained close the drain valve.
3) Now simply remove the retaining clip and pull out the sensor, its as easy as that!
4) If clogged up clean it out as mentioned above and put it back, definitely worth trying as may save you £25. If it doesn't work simply start again and replace the sensor!
5) Once replaced and retaining clip is in re-fill the boiler and open the central heating valves and fire up the boiler!

Fingers crossed cleaning this out will work for you!

Hope this helps someone!

 

[muggles]

Well worked out, it's a known issue (or at least I already knew about it...), cleaning the sensor often does the trick

 

[Georgeyboy18]

Thanks, sadly when I tried searching for help on the F9 fault I couldn't find anything about it so was a matter of trial an error!

If this post helps one person then it's been worth it!

 

[mickyg]

you might wanna clean your system, otherwise you'll be getting lots of practice

 

[acdcdas]

Hi, I'm having the same problem with my glowworm flexicom 35cx.
Its just out of warranty but the pressure error (f9) keeps coming up unless i get the pressure up to over 2.5.
i have been told by the plumber that installed it that it is probably a blocked or faulty sensor.
can anyone confirm that the replacement process is the same as mentioned at the top of the thread on a different model?
cheers

 

[Terry7556]

Yes
Do not repressurise the boiler to 2.8 again or you may find this happening where water leaks out below the pump and the housing it is attached to

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• Terry7556
• 7 Jan 2015
• 2

Over £200 for a pump with housing plus labour charge
Although that only looks like a wee drip , it pizzas out if you try to put water into the system,

 

[acdcdas]

it has been leaking water when i increase the pressure.
I will check the sensor today, do you think its too late for the pump as its leaking already?

Cheers

 

[Terry7556]

If it is leaking between the pump body and the plastic housing it is attached to , then it needs replacing. The pump body and housing are supplied together if it is a genuine Glowworm part You purchase.

 

[acdcdas]

i see. is there any chance that if i get it operating at a lower pressure that it won't leak and the pump will be ok?

just hopping for the best really.
if not, do you think its easy to replace the pump myself?

Thanks

 

[acdcdas]

Just wondering if i need to isolate the gas valve too?

 

[Agile]

It might not leak at a normal operating pressure of 1-2 bar.

But having now leaked it might well continue leaking or it might just start leaking sometime in the future.

Boilers need careful attention if they are to work well for long!

Tony Glazier

 

[acdcdas]

I did it, cleaned the sensor and its working like a dream.
the leak i had noticed looks like it was coming from the overflow pipe not the pump fortunately. even though I'm not sure why the overflow pipe would be leaking still

thanks

 

[Terry7556]

The valve that the pipework connects to (red top r/h side of pump) opens or should open when pressures reaches or exceeds 3 bar
The two faces/seats of the valve do not sit perfectly flat after this as dirt or tiny ices of grit cause this and it weeps , losing pressure

 

[NotAPlumber13]

I hope this helps someone else.
I had intermittent F9 error with our GW Flexicom 24cx that eventually got unbearable. I saw the post from Georgeyboy18 and decided to try it. Simple enough for a not plumber like me. Got the pressure sensor out and cleaned it although it did not look very dirty. Then before I put the sensor back I lit inside the hole where it goes and saw that there is some type of filter. Removed the connector to the flow pipe and pulled the filter out. Cleaned it and cleaned inside the pipe. It looks like there were rust deposits around the filter that were obstructing the flow.
My boiler has been working without any problems the last three days.
Good luck.
Not a plumber.

 

[John Harmer]

I had numerous parts changed on my 30CXI which momentarily fixed my issue of no hot water. But then the dreaded F9 fault code appeared. It turned out to be the overheat thermostat had popped out. Ironically an F5 error code....not in the trade myself, but i can totally comprehend how this job could send you to an early grave. At a time like this it's not what you know, it's who you know.